Hey ya’ll. Been slowly bring my 68 XR7 back to life. Been using this site a lot throughout the process. First time poster, long time lurker. I’m currently having an issue with voltage to my coil being less than 9V after rewiring gauges and putting in vintage air. I noticed this weird wire that was ran from across the car under the dash to two identical looking red three prong plugs. Does anyone know what they do or why this wire would be ran across the car? I can’t seem to find that info anywhere. Thank you.
Welcome! You can get a free schematic of the factory wiring (which the mated red plugs appear to be) here:
But it looks like somebody has added some wiring of their own too. Only way to know on those is to trace out where they go and/or use a meter to see what voltages are present when.
Voltage to the coil is only 12V while the starter motor is engaged. With the ignition switch ON and engine running, there is a resistance wire feeding the coil that drops voltage to 9V or less. So you might not be seeing a problem there.
Thank you for the schematic link. I’ll have to see what color the wires are and find out what the plugs do. The black wire seems to run from one side wedged in the pictured plug across to the driver side and wedged into a plug that looks exactly the same.
The voltage drop issue is causing the car to not have any spark when I attempt to start it. The battery is good and it gets 12v to the solenoid when I crank the car. Something between there and the positive side of the ignition coil is dropping the voltage to about 3v. Something must have happened when I was putting in the vintage air. I never messed with any ignition wires.
I finally saw the weird added black wire you described. That’s not right, and worth figuring out. But as far as the coil goes - the pink resistance wire to the coil is under the dash, and is very fragile. I wonder if you might have damaged it just by moving wires around under there? Because 3V at the coil is definitely too low.
My brain tells me the weird wire has something to do with blinkers or lights of some sort because it goes into identical plugs on both sides. I downloaded the free schematic at WCCC but, have to find it to verify.
I’m hoping I figured out the voltage issues. I took my gauge cluster back apart and found that I’d accidentally swapped the “12v+” and the “12v+ light” wires on the speedo. Once I put them back, it illuminated and I got 12v back to the coil. I tested voltage from “+” terminal of battery to “+” side of the coil with key on ignition and got 12v. I went to start back over with getting timing right and make sure I’m good on that front and noticed the distributor condenser was totally rusted out. Hoping once I swap that after cleaning the points and getting timing back, it’ll fire up. I’ll test that theory out this weekend when the part comes in.
Not sure I understand what voltage you are measuring there, but +terminal of battery to ground should be 12.5V with car not running for a fully charged battery, and then +terminal of coil to ground should be around 11-12V with key at START, and 6-9V with key at ON.
Power windows?
No sir. Crank variety.
Power windows were not an available factory option for a 1968 Cougar. There are currently several aftermarket options available though.
Randy Goodling
CCOA #95
Of all the owner wiring mods Ive seen over the years I’ve gotta say yours ranks right up there in creativity and a good example of what not to do.
In my opinion, that black wire stuffed into the connector needs to be addressed whether it is needed or not.
I’m guessing the strands were simply wrapped around a male pin and then they remated the connector the best they could.
Also, disconnecting this wire should help you identify its purpose.
I was finally able to get the car running. After chasing my tail for days, I found a ground wire that was causing a parasitic loss on the negative side of the coil. Once I removed it and reconnected the pink wire, it fired right up. Still haven’t figured out the black homemade one, I’m thinking it’s got something to do with the exterior lighting because I no longer have reverse or running lights on my bumpers once I took the wire out.