Turn Signal & Tail Light Issues In A ‘66 Cj5

So my son’s CJ runs amazing, but the taillights and front turn signals don’t work right. The previous owner mounted nice LED tail lights, but I need to trace and possibly re-run wiring from the switch. I’ve seen multiple diagrams, but what exactly does the stop light switch do? And what does it physically look like? I’m new to Jeeps and haven’t had to require a truck before (I did lots of wiring working radars in the service, so electronics do not scare me), so please forgive my ignorance.

(Edited for spelling)

 

Sorry for the spelling error… it is the “stop light switch” listed on the diagram. Not sure what it is or what it physically looks like.

Thanks for the tip on LED lights. I’ll try a mock up with conventional bulbs and see what happens and work from there.

 

Well, after redoing all the grounds, the LED taillights light up, but they don’t work for brake lights or turn signals, and I think I found the reason why:



I have to figure out the colors (black, brown, blue, orange, yellow) as to what goes where. I suspect they are separately to each corner’s turn signal. And my best guess would then be that the “stop light switch” in the wiring diagram would be the sensor when the brake pedal is pressed, but I could be wrong on that. But we’re making progress. At least I got the headlights working today and routed the wiring in the engine compartment in a neatly manner so it looks a lot cleaner. The engine swap runs strong mechanically, but the electronics technician in me wants to slap whoever wired it up.

Zac

 

search for turn signal wiring...a couple of members have posted schematics with all the coded wiring for the switch.

 

Will do. The detailed writing diagram I found through Google showed the wiring but not the specific colors.

 

I bought an aftermarket turn signal, so I’m not sure if the colors will be the same as yours, but I took a picture of the wiring schematic anyway.

regardless, with a multimeter it should be pretty easy to figure out what each wire is supposed to do.

 

Thanks for the help. I am beginning to think there’s a relay that flashes somewhere that I haven’t found in the signal chain. I took a long 16 ga. wire and touched each lead from the Sparton unit, and we have figured out left and right, but they don’t flash. So now I have to figure out the next link in the signal chain. I don’t think it even has a hazard switch.

 

Flasher should be on the firewall, above and to the left of the clutch pedal, under the dash....

 

There is a lip on the bottom of the dash that turns towards the firewall. Slid your hand along the lip on the drivers side and see if you feel anything. Have seen flashers attached there

 

I’m guessing these two bolts are where it should be?

 

Your entire steering column, maybe even the dashboard, are from a '72-'75 AMC intermediate Jeep. They still used the Spartan signal unit, but the wiring colors will be different from the early CJ which you '66 is. This may at least point you in the right direction to get your lights figured out.
-Donny

 

Can’t find the hazard switch anywhere in a store or from an online retailer. Fortunately, there was one on an eBay auction that ended today, and I won it. Literally got my bid in with minutes to go.

 

Well, I got the taillights working, but the blinkers still don’t, even after replacing the flasher with an LED compatible one. But I noticed that both banks of red LEDS are on when I turn on the headlights, so with the flasher is always on, or something isn’t wired correctly. Guess I’m staying with hand signals until my back feels well enough to get under the Jeep and behind the dash. But so glad I got the fuel tank sending unit hooked up to the fuel gauge and the headlights put in. It’s going to have to work until Monday or Tuesday.