I need help from the Cougar community. I’m putting my 70 Cougar back together after being down for a couple of years for paint. I had it all the way down to just motor, transmission and rear end, so it could still be loaded on the car hauler. The main warning harness was never touch. All exterior lights were at one point disconnected, including the front parking lights, the front marker lights, the rear marker lights, the rear turn signals, the backup lights, and the tag lights. The gauge cluster is back in and everything works EXCEPT the front parking lights, front & rear marker lights and headlights. I did install a new headlight switch, so I tried putting the old one back on and no change. Both turn signals light up green on the gauge cluster. The rear lights do all light up on the back of the car. The rear tag light is not connecting nor are the courtesy lights connect in the door panels. Somebody point me in the correct direction. All help appreciated.
With fresh paint have you checked that all the grounds are good?
Randy Goodling
CCOA #95
Randy, I have not checked each individual spot but I will start there. Thanks for the advice.
Grounds are a good place to start, By chance did you put in new turn signal housings? There are a few different variations, 69 and 70 wire differently. Then there are the 1970 Mustang Mach 1 and the Comet and Mavrick units.
Circut breaker in light switch ?
I used the original turn signal housings.
I’m a tad confused on what has to be grounded. Does every light ground to the chassis? I know there is a ground wire back by the fuel filler neck. I know the entire lower dash has a ground wire connected to it. Everything in the guage cluster works, all interior lights work, the rear tail lights work. Just no headlights, side marker lights, parking lamps or turn signals. I’m going to take the wiring diagram and just start checking every connection and test my grounds.
on '67 and '68 there is an inline fuse for the turn signal circuit. 15 amps if I recall correctly. I don’t know that it was still used in 1970.
There is a ground on the ground of the core support. IIRC it grounds the lights, horn and other items not part of the engine harness. This may, or may not be the problem.
badcatt, there is a horn ground. It is NOT hooked up currently but I don’t see the horn as part of the circuit for exterior lights.
Something else I’m wondering, it’s unclear on the diagram where there are grounds. There is a ground back by the filler neck and I’ve checked that. This morning, I checked every connection. I pulled each of the rear brake light bulbs. The rear 6 bulbs were all on. Each one would go out when I removed them from the taillight enclosure except for the inner 2 by the fuel filler neck. I thought that was odd. Are those bulbs, the only ones that ground to the chassis?
I see the front turn signal housings are grounded to chassis. Make sure you have a ground there. It is not a wire, the nuts should have the washers with serrations on them. To much paint on the back side of the valiance can keep you from getting a ground.
It’s been a while since I played with my electriacl system.
badcatt, great catch. I’ll double check that. Thanks!!!
To troubleshoot electrical problems you have to have a few tools. You can get a multi meter at Harbor Freight for less than $10. You can use it to instantly find out if you are getting voltage at each location and tell if the is continuity to ground. At a bare minimum get a test light. You can’t look at electrical problems and figure out the problem.
batcatt is the man!!! He was exactly right. I took a small wire wheel on my drill and cleaned a spot on the tabs on the back of the front valance, cleaned the nuts and threads on the parking lamp housings and… BAM, all the lights are working now!. Thanks to everyone that made suggestions.