I installed pertronix and a new 1.5 ohm flame thrower coil on my 302. I took a voltage reading like the directions said and I got 5.75 volts. I need 12 volts. I need to take out the resistor but I don't know where it is. HELP!!!!!
As I understand it the hot wire to the coil itself is the resistor on our cars. I know mid 60s cars have seperate coiled wire resistors... another member will have tackled this for certain I'm sure.
This is true...the wire itself is a special resistance wire, in fact if you follow the wire far enough to where you can see the insulation without any grease and oil on it, the message "resistance wire - do not cut" is printed on it. I guess I would run a new wire from the ignition switch out to the coil bypassing the factory wire altogether.
Get the full 12 volts to it. Defeats the purpose of the flame thrower coil if you only get half the voltage to it. (If it runs at all)
Besides the ignition switch in the car, where would be the easiest place to pick-up 12 volts to run to the coil? Preferably under the hood.
Nick, I think you will end up going into the dash area anyway to find a switched voltage source. Nothing else under the hood that I can think of is switched voltage.
I think you can follow the stock resistance wire back and you will find a splice. You can check the voltage at that point by inserting a pin into the wire.
Yeah, on my '70 the resistor wire plugs into a connector right beside the master cylinder. I just cut the wire near the connector and soldered on a piece of 16 AWG.
That could work too .... I've done that on a boat I installed the Pertronix into. Cut out the resistor part of the wire. If I remember right it was a little fatter wire back to the splice and it was easy to find where to cut it. But that was a Mercruise I/O.
Away around it is to use a relay. Operate the relay from the original coil lead and wire so the relay passes full 12 volts from another source, to your new ignition. No need to get all involved behind the dash.
I followed the coil resistor wire back to a plug. The plug was shared by two other wires (oil light, temperature light). I noticed another plug next to the three wire plug that had two wires going in and one wire cominig out. That wire went to a plug that was not plugged into anything. It ended at the front end of the intake manifold where it just layed there. I have no idea what it should go to. I do not have A/C. I checked the wire and it is a 12v key on only power source. It is a 16 gauge wire so I extended it with 16 gauge wire and connected it to the coil. I rechecked the voltage at the coil and got 11v. When I checked the wire by itself it was 12.5v. I lost 1.5v when connected to the coil and have no clue why. The car started but I still need to work on the carb so I couldn't tell if it made that much difference. I didn't have to put starter fluid in the carb this time. When I was getting 5.5v to the coil the car would start but I had to use starter fluid. I think my accelerator pump is gone.
There may be a tab under your voltage regulator that is 12v switched. There is on my Mustang. Also, the original Petronix stuff will run on less than 12v.
I know this is a really old thread but maybe someone can help me. I have a 71 Comet and I spliced a brand new wire from the Plug that hangs right near the master cylinder which had one red going to the coil, one yellow going to the oil pressure sending unit, and one orange that is just hot. Unfortunately I have never heard about the exterior resistor needed for coils (or resistor wire that apparently was what I spliced) until today. Burned my points and have no spark out the coil wire (that connects to top of dist.). Then I read all this stuff about the resistor wire lol. So should I go buy some resistor wire and re-splice that wire I took out from that plug so I can use the original "exterior resistor required" coil? Or just say F it and get a pertronix that can use 12v hot coils?
