1974 F-100...

Having some fun electrical gremlins and need advice. It first started out as having lazy turn signals which have totally ceased to work; even though I have replaced the turn signal relay and the emergency flasher relay. I also have flickering head/dash lights...

Now I have been informed that my brakelights work intermitently (sometimes only one side comes on while braking, then neither side comes on, and then the other side will be the only one that comes on). Too bad I ain't running a Disco.

I have replaced all fuses and cleaned up the fuse box, dipping the ends of the fuses in dialectric grease for conductivity, all relevant grounds are cleaned up but I am over my head on this one.

Any specific advice?

 

Help.

 

Well Gene, all the things you mention relate to the headlight switch & turn signal switch.

1st thing I would do is clean all the grounds.

 

Put the turn signals on, and then walk around the truck. See if any of the lights are on all the time, or are very dim and on all the time. If you find some that are lit, take the bulb out and clean the outside of it up, and also the socket connections.

 

Could it be that you've gone a little too crazy with the dielectric grease? The stuff isn't a conductor, it's an insulator. The reason it's put on electrical connections is to keep the air away from the clean metal and by doing so, prevent corrosion in the long term. It won't magically fix a marginal/(dirty) connection. It'll even make a poor connection worse.
First thing I would recommend is take a test light and check to see if you can get any flicker, glimmer or glow from the base of the bulbs with the turn signals on (or the hazards). If so, bad ground. If not, pull the bulb and check for power on the contact(s) in the socket. If so, bad bulb. If not, keep working back toward the turn signal switch checking any connections along the way.

 

Welp, I replaced the light switch and I still have the flicker. And the turn signals still fail to work. I guess that I will replace the signal switch next...