The only fuse I can find on my CJ5 is inline between the ignition switch (Acc circuit) and the flasher (10 amp). There is no visible fuse on the light switch.
This fuse to the flasher blew, so I replaced it. It blew again.
Unfortunately, I can’t remember if it blew when I applied the brakes or turned on the headlights or used the turn signal.
All power is now lost to the rear lights. The headlights and front parking lights are working, but not the turn signals.
The PO had installed LEDs on the rear. After the fuse blew a second time, I figured it was a good time to replace the LEDs with traditional filament lights, which I wanted to do.
After disconnecting the LEDs and isolating the wires (no rear lights connected at all at this point), I replaced the fuse and this time it didn’t blow.
Before connecting the new rear lights to the three lines running to the rear, I tested the lines for power. No power on any of them.
I ran a straight line from the battery to the rear lights and they work fine.
All the wiring looks ok - no bare wires that I can see or feel.
All thoughts are appreciated!
Mytwojepps2020,
Your signature block shows "Olaf" a '61 CJ5 - is this the one you're working on? Do you have a Service Manual (SM) that covers CJ5/CJ6, e.g. SM-1002-R6 (early) or the SM-1046 (late)?
I see both have wiring diagrams for the CJ5. There are two wiring diagrams for CJ5 (up to SN 49248 and the other after SN 49248). In the late SM I see one additional wiring diagram labeled, CJ5 Late F4 Engine. In this third diagram I see an additional fuse between the 4-way flasher and the light switch (makes me think the flasher is actually mounted on the dash as opposed to part of the turn signal switch).
Since this is a relatively new jeep to you, finding which illustrations apply will help. I did flip back to the end of of that section in both and there was a test for the turn signal switch for both manuals. It may come to that.
So far the basics. The fuse didn't blow when you removed the rear LED lights - which were installed by the PO (some work had been done on that circuitry before you got it - there could be some "unknowns"). You ran a jumper wire directly to the tail lights. Did you check both wires into the lights to ensure both filaments light up?
In your testing without the tail lights, did you test the turn signal switch to see if the front lights would blink (left/right possibly faster than normal), is the flasher and turn signal switch working? If all is well, then power to the rear 3 wires will all need power to test. My thinking is: Power on, light switch on will power only the tail lights (should be one wire that splits into a "Y" at the rear of the jeep for both tail lights. Brakes will power the brighter brake light circuit - regardless of light switch position (that should account for the other two wires; one for left and one for right - so that the turn signals will work).
Which end you start from may not matter but you'll need to systematically work from one end to the other checking as you go (at each connection/terminal). At some point you're going to find a break in the current where one side is hot and the other dead. Check each connection to see if some are touching when they shouldn't or possibly loose.
Maybe someone else has had the same problem and knows where to look.
