The Stovebolt Site Forums The Shop Area The Electrical Bay Faulty brake light. on my 1966 C-10

The left brake light on my 1966 C-10 is not working, but the turn signal is OK. I changed the brake light switch, and it is still not working. Does anyone have any idea of what could be wrong?

Doug 57,

The left brake lamp is also the left turn signal lamp...or it's suppose to be. You are indicating that lamp won't light when the brakes are applied, but will light and flash when the turn signals indicate a left turn! You are SURE it's the same lamp!

It would seem to me that a circuit isn't being made to the left brake light ONLY when the turn signal switch is centered.

Could there be junk inside the switch, or a broken contact in the switch? I think if the turn signal functions on this side, it would exclude the flasher unit.

I searched for a typical turn signal wiring diagram, but alas, no luck. Maybe help is on the way!

Stuart

I guess it could be a problem with the turn signal switch. I'll pull it out and examine it.

Doug57,

I am not familiar with what type of switch this truck has. Is it a column add-on type, or a factory, under the steering wheel type?

I found schematics for the Signal-Stat aftermarket type, and looking at the wiring diagram, it looks like it would have to be a open contact issue.

Could you flick the switch with "vigor", or shoot it with contact cleaner and see if this produces any positive results..non-flammable only!

Stuart

Stuart, If it's factory, the switch is under the steering wheel.

The contacts sit in the bottom of a two piece assembly. The turn signal lever attachs by a screw into the top half. The contacts are located above and below where signal lever is attached. There doesn't appear to be enough room to give the contacts a good dousing spray. There are two 'J' shaped spring contacts, I've seen these go bad. To get to the switch you will have remove the steering wheel. Mar-Kee still makes the switch, but there are 2-3 different ones for 60-66. You will probably have to buy the complete switch. I haven't seen just the 'J' springs. Shop around I've seen $10-30 difference in price. If the light socket and bulb are good, there's only one wire for brake and turn signal, and that appears good.

Larry

Thanks for your help. The switch is marked "GUIDE 64", so it must be a factory installed assembly. I'll remove the switch assembly, and will give it a good cleaning. Hopefully, that will solve the problem. If that does not work, I'll have to get a new one.

The problem is solved.

I removed and disassembled the switch, and found a lot of crud on the contacts. I cleaned them up, and put everything back together. Everything works fine now.

Thanks again for your help.