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Both terminals of coil hot without key in ignition

2114 Views 4 Replies 3 Participants Last post by  baylensmanfl
Hey guys, I have a bit of an electrical problem going on. I have a 68 mustang, and it's been in the garage for the winter. I went to start it the other day and it will crank over but it wouldn't start. So I did the basics, and wasn't getting any spark to the plugs. So I have a ton of new parts that I keep as extras, and I replaced everything. The dizzy cap, starter solenoid, ignition switch, coil, I took my pertronix out and put points back in (cheaper if anything burns up) Only thing I didn't change yet was my distributor. But noticed the points were firing without the key even being in the ignition. Also, both the + and - are hot on the coil all the time (both coils I have), without the key. So I poked my test light into the socket by the fire wall, and the wire in the plug that comes from inside the car that runs to the coil is hot, again without the key being on.

Next I put my test light on the back of the ignition switch, and the battery side of the ignition switch is hot (which it should be correct?) and the "ignition" side of the switch is also hot (without the key even being in the ignition). To refresh your memory, the ignition side is where the pink resistor wire and a green/red stripe wire run and come out as the single wire that goes to the switch. So I unhooked the ignition side of my switch, and found out the pink resistor wire is hot at all times and the other wire isn't, without the key on as well. So my understanding I have a short somewhere right? Are there any wires that would feed power into the ignition switch I need to check? Because the resistor wire is getting power when it's not even hooked up to the ignition switch. When I unhook the ignition wire from my solenoid, it kills the power to the pink resistor wire.

Also, is the ignition side of my starter solenoid supposed to be hot all the time, because mine is, even on the other one I have as a back up. I've got it narrowed down this far, and just wanting to see if I have an issue between the battery and pink resistor wire. And is there is a SAFE way to bypass this or what I should check next? Could the pink resistor wire just be shot? Or would it be something shorted coming into the car from the battery since it's giving it power? Any help is appreciated as always guy. Thank you, and drive safe this year!
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The wire that connects to the + side of the coil should only be hot with the key in the on or start position as it receives power from the ignition switch. If that wire is hot all the time, you have an issue somewhere back toward the ignition switch. If you have 2 small posts on your solenoid, one is hot with the key in the start position and the other goes to the neutral safety switch. First I'd disconnect the wire from the + terminal on the coil and the connectors from both the small studs on the solenoid. Then I'd connect a wire to the + battery post and touch the other end to one of the solenoid studs to see if the solenoid will crank the starter. Then I'd jumper a wire from battery + to coil + and use my solenoid wire to crank the engine. This should give you spark at the plugs if everything on this portion of the starting circuit is good (this takes the ignition switch, etc. out of the starting circuit). Be sure the trans is in neutral/park,the hand brake is set and the tires blocked (to prevent accidental transmission engagement).

This is only good if you haven't done modifications to the electrical systems as that changes the possible parameters. Also, check for signs (droppings) of rodent damage.
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As a matter of fact, I did this, I'm sorry I forgot to mention it. And it was giving me spark again. But I still have power at the ignition side of the solenoid without the key on, I also have power running from the fire wall plug to the coil without the key on. As soon as I unhook the ignition wire from the solenoid it kills the power to the pink resistor wire.
In a nutshell, the wire that's labeled "battery" on the ignition has power at all times, and the pink resistor wire has power at all times.
Does it still have power if you pull the pink and brown wires from the solenoid? Remember the pink wire in front the brown wire in back when hooking it up (its just like underwear). If you have power with the two wire pulled off the solenoid you have a problem in the harness. start at the alternator and work your way to the firewall looking for burns or pinches. If you don't have power when the wire is pulled i'd try a new solenoid.
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