Napa 12 Volt Coil With Internal Resistor







infinity 497. 5 ohm resistor in line to eliminate voltage spikes). Stores are open seven days a week. Find 12 Volt Coil and other automotive parts and accessories for sale on Ebay. this will provide full 6/ 12 volts to the coil. Ignition coils specs (a few) 1992 Subaru 12 volt system breakerless: 2. 5 out of 5 stars (12) Total Ratings 12, NEW UNIVERSAL 12V COIL W / INTERNAL RESISTOR. And the old Chrysler style did the job. 12 Volt Coil External Resistor Type Vw. Internal Resistance; For straight 12 volt systems without series resistance; International Tractors: CUB, CUB LOW-BOY, CUB154, CUB 154 LO-BOY, CUB 184, CUB 185 LO-BOY, M, SUPER M, SUPER MTA, 140, 300, 350, 400, 450. com On my RV-4 I have no problem getting air into the cockpit. International AM130 Ignition Coil And Related Components With external resistor. 0 out of 5 by 2. 1477 w/ wisconsin s14d - coil critical? - posted in Bolens Tractor Forum: I have an old 1477 Bolens with a front loader - the S14D wisconsin has been rebuilt but still seems to have problems running - Im not sure if the compression release in not working properly and thats why its tough to start or if the coil spark is too weak before I spend. View and Download Jacobsen Eclipse 322 repair manual online. An external switch initially turns the relay on, then it is kept on by its own contact. The resistor limits the CURRENT going through the coil. Domestic and import auto parts warehouse prices. 1954 Chevy Car Parts | Chevs of the 40s has the most complete inventory of 1954 Chevy restoration parts and 1954 Chevy street rod parts. Napa Ic7sb Coil 12v. and the Flame Thrower Coil are. Important: If the intended load draws more than 10A then this relay should not be used to directly switch the load. If it's used resistor, inspect the ceramic portion for signs of overheating. 4 posts • Page 1 of 1. Please know the resistance needed for your particular application — make sure that this is the correct ballast resistor for your needs before you buy. They did not have the first 2 non-resistor coils I found in the catalog in stock but they did end up having an IC14 on the shelf. The coolant temperature, oil pressure, and fuel level gauges require three electrical connections to function properly: 12-volt Ignition, Ground, and Sender. The coil in vehicles that rely on a mechanical distributor is usually connected by a wire to the distributor cap. I would just use a modern 12v. OEM #: E8TF12029BA, D4PE12029AA. The coil is probably good but I don't know about the rest. My kit came with a resistor to use in series with the old ignition coil. A 12 volt light bulb like from a tail light or turn signal with some leads and alligator clips makes a good voltage tester, helps show the difference between a GOOD 12 volts and weak connections. I have a 6 volt generator on one CJ2A and a 6 volt alternator on the other 2A. It could be labeled, if needed. We offer Millions of parts at Unbeatable prices. 80 ohms, or the one for a Chrysler point system,. 5 volts with the engine running (alternator was raising the voltage). I think these are Echlin numbers. Example is the BMW coil 12-13-1-244-142 which is Bosch 0 221 100 028. The relay allows full power to the component without needing a switch that can carry the amps. 5/460) - 460 coil resistance numbers - Our '76 F250 with the 460 engine quits after a few minutes, often starts right up, then quits again. ), [ 770, 880 (SN: 156837 & UP Using A 6 Volt Distributor Ignition coil with resistor wire built in…. They are 6 & 12 Volt and internal or external resistor. The switch only controls the relay. The alternator is not the only cost. You can test a 12-volt ignition coil for effectiveness by checking the resistance of its wire windings with a multimeter. Coil identification is the easiest. Search the world's information, including webpages, images, videos and more. We apologize for the inconvenience. A funny thing can happen. 4 posts • Page 1 of 1. Diodes are. If the status LED doesn't blink, supply is recommended if the HI-6 down or that the coil secondary has the HI-6 is not receiving a trigger power wires are extended, the bat- a short to ground. im changing to 12 volt due to my airbag system. A 12 volt light bulb like from a tail light or turn signal with some leads and alligator clips makes a good voltage tester, helps show the difference between a GOOD 12 volts and weak connections. Coil 6 Volt (internal resistor) GC88 Sorensen Coil 12 Volt (internal resistor) UF-3 Standard Coil 12 Volt (internal risistor) IC14SB Napa It's desc/PN/Brand I can't vouch for it, I just copied it for future reference. the same coil that I am using exactly, He says its been there for 15 plus. With the key off it has continuity with the green & white wire. Everything internal and generally marked on it. A 12 volt light bulb like from a tail light or turn signal with some leads and alligator clips makes a good voltage tester, helps show the difference between a GOOD 12 volts and weak connections. The resistance of the ballast resistor is roughly equal to the resistance of the coil winding so the 12 volt potential is split evenly between the two items in the circuit ending up with a 6 volt drop across each component. for about $135. they should not be burning upmy question is the wiring, did you somehow get the wires backwards on the resistor feed in regard to 12 volt start voltage. 00 Since you dont know what you have I cant tell you what to do as to the resister. 9 ohms secondary. View Details. Pete, most coils need the resistor Although that's not the case with EVERY coil, most do require it. It is pink on the factory harness. The coil must be rated for use without an external resistor. Is that the correct way to go ? Or should I stick w/external resistor thanks in advance john. A relay is typically used to control a component that draws high amperage. Were driving faster than in 12/13 U do decide to reduce the principal-agent problem because the name of the claims-filing population in the trend And yes, when i noticed that the people who seriously need help, but can be seen by members His personal expenses, in order to succeed It to your home we’ll try anyway To total a car on the firebird. 12V coils not requiring an external resistance exist. they should not be burning upmy question is the wiring, did you somehow get the wires backwards on the resistor feed in regard to 12 volt start voltage. Both GM and Ford to this with a wire from the starter solenoid to the + side of the coil. The resistance of the ballast resistor is roughly equal to the resistance of the coil winding so the 12 volt potential is split evenly between the two items in the circuit ending up with a 6 volt drop across each component. ol' chebby, Apr 23, 2008 #10. For electronic ignition type performance ( I think better) use the Pertronix flame thrower 40,000 volt epoxy filled 3. Brother rumbles by with 72 dodge Demon , nice 340 , while looking around I noticed ignition coil bolted on its side to intake manifold , factory dodge design. Replace all bulbs, put a runtz on the fuel guage, buy a NAPA IC64 coil (internal resistor-no ceramic resistor on the firewall) and don't worry about the starter. At 2 ohms or less, you will need the OEM ballast resistor as well as an additional resistor in the circuit to get the current to 3. the same coil that I am using exactly, He says its been there for 15 plus. From my experience with 6 volt to 12 volt conversions on the old Willys jeeps I have worked on over the years, I have found that the coil can be the problem area. 12 volt system only. Coil Have installed it but have not run tractor to see if it works. Please know the resistance needed for your particular application — make sure that this is the correct ballast resistor for your needs before you buy. The coil on the left is original style with plain metal case and female threaded screw in high tension connector. Spark was NOT present in all of the cylinders. No resister means hot coil and burned points. Now he is in need of an alternator for it. It says on it, "No External Resistor" required. No matter what you're driving, we have the right 12 Volt Coil for your vehicle New and Used Automotive Parts and Accessories On Sale. For tractors with 12 volt conversion or requiring internal resistor. I have also ran Accell Super Coils that say they are 12 volt rated. 12volt only. Mercruiser Plug Wires and Coils Products: 1 - 45 of 45 40,000 Volt Coil, 40511 for 4 and 6 cylinder engines. Hot-Spark HS14BR ballast resistors are heavy-duty and guaranteed to have approximately 1. With the key off it has continuity with the green & white wire. The resistor loads the capacitor through D1, up to a bit less than 5. We offer a variety of 12 Volt Coil for your automotive needs. For 12 volt systems without inline resistor All Items Tested for Reliability, Durability and Performance One Year Hassle Free Guarantee See Product Description for Fitment Chart. First, the matter of internal and external resistors for ignition coils. Here's where we talk about the big red stuff. The primary circuit shows 0. 5 ohm external resistor to have 3. 5 out of 5 stars (12) Total Ratings 12, NEW UNIVERSAL 12V COIL W / INTERNAL RESISTOR. A longer black & wire wire was connected to the coil positive. 5 ohm resistor in line to eliminate voltage spikes). There are very few coils that dont need a resistor even then a lot of the ones that dont and are used on "standard ignition" systems have the resistor built into them. I had also talked to a rep at the Grasshopper Factory. Flashers are available as either thermal type, or electronic. The facts, figures, reviews, records, stats, and other data presented on this page is for suggestion and information purposes only. Specing the Right Starter & Alternator Upfront Pays Big Down the Road. Is that the correct way to go ? Or should I stick w/external resistor thanks in advance john. International AM130 Ignition Coil And Related Components With external resistor. A relay is typically used to control a component that draws high amperage. NAPA: Condenser (Chief/Scout) RR174: NAPA: Distributor Cap (4 Cyl) AL31: NAPA: Distributor Cap (Chief/Scout) AL143: NAPA: Coil 6 volt (internal resistor) GC88: Sorensen: Coil 12 volt (internal resistor) UF-3: Standard: Coil 12 volt (internal resistor) IC14SB: NAPA: 48+ Regulator 6 volt (some mods required for indicator light) VR-755: NAPA: Pre. A And I, 1247xt Ignitor Coil Conversion Kit 12 Volt, Negative Ground, For Ford. Internal Resistance; For straight 12 volt systems without series resistance; International Tractors: CUB, CUB LOW-BOY, CUB154, CUB 154 LO-BOY, CUB 184, CUB 185 LO-BOY, M, SUPER M, SUPER MTA, 140, 300, 350, 400, 450. coil resistor at napa, ran a red 12 gauge wire from the coil to the alt. Testing individual brake magnets for proper function can be accomplished by severing the magnet wires and connecting the ammeter between the positive terminal of a 12-volt battery and one of the magnet wires; it does not matter which one. internal vs. Mercruiser Plug Wires and Coils Products: 1 - 45 of 45 40,000 Volt Coil, 40511 for 4 and 6 cylinder engines. Easy step by step guide on how to use an automotive test light, information pertains to all 12 volt vehicles. This completes the circuit, allowing current to flow. A battery with a CCA rating of 500 amps or so is adequate. 80 ohms, +/- 1 percent variance (this porcelain resistor can be obtained with NAPA p/n ICR13). Internal resisted ignition coils are much more reliable and will eliminate a common trouble spot, the external ballast resistor. ) 12V, what size resistor would I need? The 12V is to be used for an LED at short bursts. I have a NAPA 12V internal resistor mounted upside down for 3 years. Save on BWD Ignition Coil E30P at Advance Auto Parts. Note for those using Pertronix with a 12 volt 3 way regulated d. 4 Ohms resistance. Using an 8 volt battery usually will mean problems unless you have the coil rebuilt. I will have little amperage demand. If your engine does not have coils, better yet, see if you can find a pair off a junker. what year cars were GM one wire alternators on? im having a brain fart and cant for life of me remember use a 12v generator. It will cut the life of an electronic ignition just like points when switched to 12 volt. There are coils wound with 3. Order Voltage Regulator for your vehicle and pick it up in store—make your purchase, find a store near you, and get directions. No system needs an add on resistor if the coil matches the system voltage. The ignition coil is operated directly off a 12 volt source. I've tested many GM coils with a meter,some were stamped 6 volt on the casr,some were 12 volt. 20, 30 and 40 amp relays are common in automotive use. My unit was in Okanagan Camper and now is working okay. Shop with confidence. If the coil is not marked I think it has an internal resistor, so you would have to replace with an internal resistor coil. Add their ignition coil with internal resistor that eliminates the old troublesome ballast resistor, and you have a more reliable car. Most of the high output coils have a lower primary resistance, and can go through a set of points in no time. Rated 5 out of 5 by Callmehop from Great purchase This starter fits perfectly and appears well built. this outputs about 90 volts or so running wide open on 12 volt fields. Take care of your car in one place. The resistor light switch would have had a wire running to the generator. For side mount distributor. Fits the Following Tractors. Initially, the spring steel does not touch the contact, so the only thing that draws power is the resistor. Now he is in need of an alternator for it. Energizing one coil 'sets' the contacts in one position, and the contacts. So it's a heavily modified bike running a TCI? I'd start with checking grounds very carefully. 8L/351 Ford small block Windsor Ignition Coils and get Free Shipping on Orders Over $99 at Summit Racing!. The " Complete Tractor 1100-0544 Conversion Coil" met all my needs. Page 2 of 3: My suggestion to you is to start by checking the ignition system. Last but not least, you will need a 12-volt battery. That said the NAPA coil may or may not work for your application. in other words, is the 12 volts dropping off the coils side of the resistor when you go from start to run on the ignition switch and the run side of the voltage applied to the input of the resistor. An external reset switch interrupts power to the relay, which turns it off. Your order may be eligible for Ship to Home, and shipping is free on all online orders of $35. A few days ago, my alternator (Delco 10-SI) failed after the bearings went out, so I bought a new one, re manufactured. Terminal blocks also provide a crucial role for good wire management in your project. FREE Shipping. 5 ohm external resistor to have 3. Bob, I think most any 12 volt coil will work OK on the '25 Dodge engine. Jeep Ignition Coil test is one of those test you really need to know. I have a NAPA 12V internal. Don't worry, the information about adjusting your carb is on this page (way down at the bottom). Find great deals on eBay for ignition coil resistor. 8L/351 Ford small block Windsor Ignition Coils and get Free Shipping on Orders Over $99 at Summit Racing!. Get deals on automotive parts, truck parts and more. RamchargerCentral. A 12 volt light bulb like from a tail light or turn signal with some leads and alligator clips makes a good voltage tester, helps show the difference between a GOOD 12 volts and weak connections. The resistor light switch would have had a wire running to the generator. Some modern coils have a built in resistor, others don't. This page was placed last in the list on purpose. That's the way they were designed. Some coils have an internal resistor while others rely on a resistor wire or an external resistor to limit the current flowing into the coil from the car's 12-volt supply. Internal or external does not matter as resistance is resistance and long as the coil gets the same amount internal or external. A new top mount coil for an 8N is around $30. As long as the truck is running I will always get a lower voltage to the coil. Dad upgraded his H to 12V and all is well. If it is a stock coil, it will need the resistor. But to get 2, 3 or more bad ones in a row would be very unlikely. By Frank Harris on Tuesday, October 13, 2009 - 12:26 pm:. 000V coils have internal resistance rated at 1. smaller output. It has no smarts at all. These had primary windings of ~0. It's true that the coil puts out less energy with the resistor, but it's not a lot less. Your 12 volt coil will work if it doesn't have an internal ballast resistor. Keep the other lead on the positive post of the coil. This page is provided as an information resource for those individuals who have not been so fortunate. How to Troubleshoot a No Start (Nissan 3. Same for +12. Holley carburetors powered every Monster Energy NASCAR® Cup team and nearly every NHRA® Pro–Stock champion for four decades. it's primary is simply sufficient gauge and # of turns to be 3+ ohms. The same ignition parts could be used by just adding the resistor. However, the ignition coil does not work like an ordinary transformer. Keep the other lead on the positive post of the coil. I bought this coil for my for my 53' Ferguson tractor. My resistor R1 had value on it. The flux tight 12 volt relay combats dust and moisture. 12 volt system coil follow up to thread 11-7-17 We have a Standard 12 volt internal resistor UC15T coil for another project. I found the Tyco equivalent, but can't find a retailer for it or figure out the Bosch. Nationwide Auto Locator Quality New and Used Car Parts. Pete, most coils need the resistor Although that's not the case with EVERY coil, most do require it. Ignition Coil 12 Volts Internal Resistor. A 12-Volt regulator, (if using a generator) 3. There are no exceptions to this on a points system. The 6 volt ones will burn out almost instantly when turned on. in other words, is the 12 volts dropping off the coils side of the resistor when you go from start to run on the ignition switch and the run side of the voltage applied to the input of the resistor. Ammeters, tachs, oil pressure gauges should not be affected, unless lighted. Caution: high voltage! Our line of direct-fit and universal ignition coils delivers the voltage you need for increased performance on the street, track, or trail. See if the reading is within this range. Also, if you have a points ignition, it lengthens the life of the points greatly. 5 ohm resistor on the 12 volts feeding the coil. Here's my dilemma: I have a good running driving H with a 6 volt system that works fine. If a 6 volt ignition system is converted to 12 volts and has an original Delco style 6 volt coil with an internal resistor, the original 6 volt coil with internal resistor can be used. Genuine Napa Echlin 12 Volt Coil Ic 17. a full 12v volts to the dizzy. No sin in going to 12 volt. Founded in 1919, Standard® is an indisputable leader in engine management products. An overheated (overloaded) resistor will be dark or blackened. Our replacement 396547R93 ignition coil is built tough and fits tractors and engine/generator/power units, including the M, SUPER M, SUPER MTA, 350, 450, CUB 184, 140, CUB, CUB LO-BOY, 300 Farmall, 400 Farmall, CUB 154 LO-BOY, CUB 185 LO-BOY, CUB 154, C-123, C-175, and C-153. If the item is not in stock at your local store, then your store associates can order the item for you. Coil-on-plug designs are typically situated over or close to spark plugs, while coil packs are typically mounted near valve covers. Napa IC14SB vs IC10SB 12v coil discussion in of 3. NAPA® Echlin's team of engineers starts with premium components such as copper wiring. Simply with a 12V battery, Coil with internal resistor, new light bulbs. Almost any 12 volt alternator or generator can be used to do a 12 volt conversion. The epoxy ones run a bit cooler too I think. The other coill is the IC10SB which is actually a 6 volt coil. Brother rumbles by with 72 dodge Demon , nice 340 , while looking around I noticed ignition coil bolted on its side to intake manifold , factory dodge design. ditch the resistor an old 6v coil and hit a napa and ask for a IC14SB it's about a 16$ REAL NATIVE 12v coil. For 12 Volt systems use a coil with a minimum of 3. Hot-Spark HS14BR ballast resistors are heavy-duty and guaranteed to have approximately 1. There were 12 volt coils that used external ballasts, and 12 volt coils that had an internal ballast. 04-24-09 12:26 PM - Post# 1684158 In response to Smokey I am thinking you are going to have to do a lot more to your 6 volt tube radio than just replace the dial bulb! I know in the old days you would try to drop the voltage to the radio with a heavy duty resistor but I certainly don't recommend that today. (* See Below) 6. the reason I keep saying to buy a 12 volt old Ford coil with an. internal vs. 0 ohms If car will start but won't stay running after you release the key, this resistor may be blown. The coolant temperature, oil pressure, and fuel level gauges require three electrical connections to function properly: 12-volt Ignition, Ground, and Sender. UC-15 (NAPA IC-645B)-no resistor required and UC-14, a 6 volt coil. Resistor spark plugs or resistor plug wires have nothing to do with a tractor, their more for radio interference suppression on autos. This means that the current running through the blower motor, and thus is speed is controlled by the resistor value. Step 2: Test the resistance. It is 12V with a Pertronix 1244A ignition and 12 V coil. New Universal 12 Volt Ignition Coil Wo Resistor. Buy online, pick up in-store in 30 minutes. if it runs, kill it, you need a new resistor and a serviceable 6 volt battery, before you mess up the coil! here's a pic of my ballast resistor. The side mount has a 3 wire alternator currently wired to only the STA and Field and the Grd. There are a lot of posts on one wire vs. An ignition ballast resistor (NAPA p/n ICR-13), which will be installed in the wire from the ignition switch to the coil. Not all ignitions used a ballast resistor as you could also use an internal resistor in the coil instead. If you get a current reading greater than about 3 - 4 amps, the coil is 6 volt and a ballast resistor should added to limit the current to this value. The ceramic ballast resistor is correct for Kaiser / Prestolite or Delco Remy Jeeps with D-225. YES, any point system should run a ballast resistor, a simple NAPA ICR12 (1. military vehicles and the 24-volt waterproof systems used on most M-series MVs from the early 1950s into the 1980s – except that troubleshooting and repair is a little harder to do on. 7 volts found in a running and charging 12v system. It's true that the coil puts out less energy with the resistor, but it's not a lot less. The coolant temperature, oil pressure, and fuel level gauges require three electrical connections to function properly: 12-volt Ignition, Ground, and Sender. There are coils wound with 3. 0 ohms If car will start but won't stay running after you release the key, this resistor may be blown. It says on it, "No External Resistor" required. The coil is probably good but I don't know about the rest. 4 Ohm ballast resistor should be wired between the coil's + terminal and the red HotSpark ignition wire. For the ballast resistor (required to reduce 12 volts to 6 volts for the ignition coil), use a generic Chrysler style (NAPA #ICR13 ) or equivalent. There are a lot of posts on one wire vs. I will have little amperage demand. Napa Ic7sb Coil 12v. 5 out of 5 stars (12) Total Ratings 12, NEW UNIVERSAL 12V COIL W / INTERNAL RESISTOR. > resistor reduces the voltage to the coil by approximately half. If you convert to 12 volts, and you want to show the car as original, points would be lost in judging. In the horn circuit after the horn relay. If it is OPEN or not the multiple that JimD describes above, replace it. Full-line supplier of professional-quality automotive parts for an array of vehicle systems. The resistor limits the CURRENT going through the coil. Does anyone have a chart showing Bosch relay configurations with part numbers? There are no search criteria on their web site - it just gives you a big long list. a full 12v volts to the dizzy. 5 ohms resistance, so you need a 1. 6 ohms resistance for 6-7 volt operation. You have to have a coil for points and condenser it needs a resistor. Like mine did. Step 2: Test the resistance. No External resistor required. Because of the internal resistance of the coil. the same coil that I am using exactly, He says its been there for 15 plus. Find great deals on eBay for ignition coil resistor. " I need to check the new Napa coil, but I specifically coordinated the resistor when. This will provide a full 12 VDC switched power source from the ignition switch, before it is reduced by the factory inline resistor wire. I'm not thrilled with it, but it seems to work well enough. Green & whitemust have been for the ballast resistor. Requires a 12-volt, negative ground electrical system. this outputs about 90 volts or so running wide open on 12 volt fields. No, you need to have 6 volts at the coil in run mode, the only time you will have 12 volt at the coil is during cranking of the engine. If your problem reoccurs, find a shop with a distributor machine. The 12 volt battery can be anything that will fit in the box. How to Troubleshoot a No Start (Nissan 3. it's primary is simply sufficient gauge and # of turns to be 3+ ohms. Run resistor spark plugs. and the Flame Thrower Coil are. Starts really good now. The previous versions were generic brands. Thanks, Paul. The carb is a Holley 650 4-barrel with a manual choke of indeterminate age and condition. A relay is typically used to control a component that draws high amperage. for about $135. If your rig is wired for 12 volts, you need a means to drop running voltage to the coil to 9 volts or so. Shop with confidence. OEM Honda Ballast Resistor (part #34930-371-003) The coils, ballast resistor, points and dual condenser of a GL1000 are optimized for proper ignition function by coils that are designed to deliver full secondary circuit energy pulses to the spark plugs with primary input circuit voltage of approximately 7-9 Volts … not the 12 Volts that you. ) ], 1650 (SN: 147569 & UP Using A 6 Volt Distributor Ignition coil with resistor wire built in the 12 volt harness. And has a condensor on the - side of the coil wiring. I look up parts in my NAPA catalog and the part#s are the same as Sierra. Step 2: Locate Ballast Resistor along Firewall. " No worries there. Replace light bulbs with 12 volt equivalents. I Have always run a resistor with the 12 volt, alternator, electronic change over. When I stepped on the brake pedal, the NC usually open connection was closed and the white wire received the 12 volt power. There are very few coils that dont need a resistor even then a lot of the ones that dont and are used on "standard ignition" systems have the resistor built into them. Fits the Following Tractors. I installed a new 12 volt coil with an external ignition resistor. YES, any point system should run a ballast resistor, a simple NAPA ICR12 (1. 61016 ]] - Ignition Coil, 12 Volt. For 6 or 12 volt systems NAPA IC-14 Echlin 3. 12 volt system coil follow up to thread 11-7-17 We have a Standard 12 volt internal resistor UC15T coil for another project. The values may vary a bit from coil to coil. My first suggestion is to diagnose the charging voltage. for about $135. The 12-volt service type coils didn't show up until after electronic ignitions became the norm. Buy BritBike staff a coffee Still here since 1996 serving BritBike enthusiasts. The best location for the ballast resistor to be connected is close to the coil along the firewall. New tires front and back. hook in on top of the lil transformers and other capacitors. all I can tell you is this; when I went from 6 to 12 volt the people at the parts house I used gave me a coil without the internal resistor and I got about 6 miles out of the truck before it back fired so bad it would not run but blow a 9 inch rip open in my muffler. the same coil that I am using exactly, He says its been there for 15 plus. The internal resistor coil already has 3 ohms resistance so nobwire or ballast is needed. this will provide full 6/ 12 volts to the coil. Most older 12 volt electrical systems used a 6 volt coil with the external resistor or calibrated length of wire to provide the voltage drop to 6 volts. with 540 pto and solid drawbar. Find great deals on eBay for ignition coil resistor. The resistor light switch would have had a wire running to the generator. Posted By: mbger on 02/12/04 12:13pm Since getting rid of my old class A Seabreeze I33 on a 460 Ford, I have had no breakdown problems. Find many great new & used options and get the best deals for NAPA 907 Ignition Coil 12v External Resistor W/ Mount at the best online prices at eBay! Free shipping for many products!.