The Stovebolt Site Forums The Shop Area The Electrical Bay New with Questions-66 C10 turn signal/brake Light

Hello all. Just joined and already have questions (which is really why I joined).

I've got a 66 C10 and the lights are becoming like a Christmas Light nightmare. Only the headlights and the left turn signal/brake light worked when I got it. The wiring was a mess. At this point, I have everything working except the right turn signal and brake light. I was told when I baught the truck that it probably needed a new turn signal switch, as this was the explanation for the right signal not working. So, my question is this; would the problem with the turn signal switch also affect the brake light on the same side?

I know that it is not a problem with the socket (rear) as it works when I jump the wires to the left side. This is where I am stumped. Any ideas?

Yes. The brake lights feed through the turn switch. Use a test light & make sure there is no curent from the switch to the right rear light. You should have a wireing diagram. I think it is a green wire. That model particularly bad about that. I have taken off the strg wheel & the horse shoe & adjusted the contact springs but it is kind of a tedious job.

Thanks for the feedback. I'll give that a shot. You are right about green.

Thanks again.

Also make sure you are getting a good ground.

I added grounding straps all around the other day, so I'm still thinking it's the switch.

There MAY be a body connector somewhere on the firewall that has the rear lighting harness running to/from it. I'd check and see. If so, it is the best place to check the condition of the entire rear harness. Also there is a big connector that connects the turn signal assy to the harness. Find the dark green wire on the left hand and check there. The light green going to the rear is the back-up lights. The Right turn/brake is the dark green one, and the left is yellow. All other rear lights are on the brown lead. It goes without saying to double check your grounds to the frame!

best wishes,

Les

New development - not of my doing. Yesterday, I was out driving the truck when I accidentally turned on the right turn signal - it worked, but not consistently and only on the rear. Still no brake light on that side.

The whole housing below the steering wheel moves, and if you push it a certain way, the right turn signal works. Got to crack it open and figure it out.

Check the wiring diagram for correct wire color codes.

Is this a 6 wire or 7 wire turn signal switch?

Is it a Chief or Arrow or Signal Stat switch?

Most use the Green and Yellow wire for the front turn signals only.

Some use the brown (Right turn/stop) and orange (Left turn/stop) for the rear Combo Stop/Turn lights. Older Chief used grey with color strips. Usually the red was power, on some it is stop fed to switch.

Best is to determine which switch you have then follow color codes to rewire turn signals and stop lights.

Almost forgot...is this a factory switch mounted in steering column?

Dumb me...forgot to ask important question.

It's a 7 wire switch (I believe) as the connector that comes from the column has 7 wires (4 on one connector, 3 on the other). I also believe that it is factory and is still in the column. The guy that sold it to me didn't seem to know much about it. What I do know is that I have a brown wire for tail lights, yellow for rear left turn/brake and dark green for rear right turn/brake. If I have the wiring in the front correct, it looks like blue is the front right turn signal.

It may be as simple as the signal arm can't get the switch all the way into position for right turn or make the brake contact. If you remove the steering wheel there are three screws that hold that hub tight. With that loose, there will be no end of electrical nightmares in the column. Every single replaceable part in there is available, too, in case you need 'em!

Best wishes,

Les