C2 Coil wiring

[Mike Swanson]

I have a really stupid question. I am removing my manifold today. On the + side of the coil there were two wires, 1 for the distributor and another wire that went nowhere, just hanging. Where the heck does it go.

I looked at the service manual and now I'm really confused, it shows coil + should be resistor and starter solenoid. Coil - should be distributor and only distributor.

What the heck is going on here??

Thanks,

Mike

[Mike M.]

Re: C2 Coil wiring

sounds like someone cut the violet wire from the starter solenoid to the coil. its purpose is to energize the coil with full 12 volts when in crank mode. it drops out when ignition switch returns to run mode at which time the coil receives just 6 volts for run mode. the 12 volts during crank mode allows for more spark during cranking. the ballast resistor allows for 6 volts during run mode, thus sparing the points from premature deterioration in the event the coil and hence points were receiving 12 volts in the run mode. mike

[Mike Swanson]

Re: C2 Coil wiring

Mike,

OK, I'll check the starter solenoid to see if the other end is still on there. Will you please clarify what should be on which side of the coil +/-?

Thanks,

Mike

[William C.]

Re: C2 Coil wiring

Coil - to the dist.

[Stephen L.]

Re: C2 Coil wiring

If the hanging wire is black it could be for a capacitor for radio noise suppression. Do you have a capacitor mounted on/near the coil??? Its a small aluminum cylinder.

[Mike Swanson]

Re: C2 Coil wiring

Steve, It is a very thin light purple colored wire. It seems that the whole damn this was wired backwards. It had distributor and this hanging wire on the positive side of the coil and the twin red leads on the negative side of the coil. I think it is backwards.
I have to crawl under and check the starter solenoid to see if maybe the hanging wire was on the solenoid. I doubt it since it seems that Bubba has gotten hold of this.
I just want to put it back correct so that;s whay I have been asking for help.

I have a few pics to send by e-mail of how it was before I removed anything if anyone is interested in helping me sort this out.

Thanks,
Mike

[Stephen L.]

Re: C2 Coil wiring

The 2 "pink" wires should be on the + terminal. One is a 12 gage which goes to the ballast resistor. The other wire is 18 gage and goes to the starter solenoid on terminal "R". Also on the + terminal there should be a short black wire leading to the radio noise capacitor (CORVETTES ONLY). The - terminal will only have a black wire to the distributor. If you have a "purple wire that is "cut and hanging" someone possibly was running an auxiliary tachometer (a real racer guy) and just cut the wire when the tach was removed. Place a volt meter on the + terminal and start the car. During this brief period you should see something close to 12 volts. After the car starts and you have released the key the voltage should back off to something under 10. What this means is that during a start cycle the coil sees full battery voltage and when the car is running the ballast resistor is introduced into the circuitry and the voltage at the coil drops to this reduced voltage to save the life of the coil.

Electric tachs get their engine RPM signal from the disributor points on these cars. The typical place to connect this up is at the - terminal on the coil.

[Mike Swanson]

Re: C2 Coil wiring

Steve,

Thanks for the excellent explanation. Given that the thing was wired backwards ie. distributor on + and solenoid and balast on -, should this have even worked? What would be the effects.

Thanks again for all your help,

Mike

[Stephen L.]

Re: C2 Coil wiring

I'm not an expert in the specifics of coils, but it is a coil or inductance which is a coil of wire. It acts like a transformer increasng the 12v to kilovolts for the high voltage to the spark plugs, the frequency dictated by the points opening/closing in the distributor. It shouldn't hurt the coil winding to be connected in "reverse" but there is the possibility that the dynamic performance might be altered when wired this way. You may experience an improvement in ignition and vehicle performance.....

[Mike Swanson]

Re: C2 Coil wiring

Steve,

Thanks so much for all you help. I will be putting everything back together this week.
Mike