Electrical Turn signal problems

[73_06]

I have a 1973 CJ5, and I have replaced quite a bit but I have gotten to the electrical and my headlights and break lights work but my turn signals are being kind of weird. When I flip the lever to turn on one of the signals all 6 of the light flash, those lights being headlights, taillights and running/turn signals. The headlights are also led’s and haven’t had problems until now. Please help, trying to get it road ready.

 

[CJ]

• Is your wiring stock or aftermarket?
• Are there relays for the LED headlights?
• What turn signal / steering column do you have?
• What happens when you turn on the hazards?
• Do you have an analog meter, DVM, test light, or Power Probe?

On the stock 73 CJ wiring, headlights do not go through the blinkers / hazards as there are actually two physical flashers and they are on separate circuits than the headlights.
Almost all electrical problems with CJ's are ground problems.

Here is a factory wiring diagram from the FSM (same as 73.) -->> 1972 CJ5 Wiring Diagram

 

[TSB8C]

Agree on ground problems. When lights that are connected to each other (even partially) like brakes/blinkers all flash at the same time, it's usually because of poor grounding, causing "feedback" through the positive side of the interconnected circuits. A few checks of common areas may find the source:

1. The front turn signals in the grill. These have two positive wires (one for marker light and one for blinker) and are grounded by the mounting screws into the grill. Rust, corrosion, paint can block the grounding contact. Test by touching a clip lead between the light housing and a known good ground. I soldered a ground wire to the back of my housings and then connected that to the headlight ground wires just above them.
2. Ground connections on the tail lights. These are grounded with a wire screwed to sheet metal behind the fender well. Tires throwing dirt/water can cause rust/corrosion and create a poor ground. Test with a clip lead on that screw lug to a known ground.
3. Front side marker lights. These have no ground (due to how the CJ changes blinker functions when lights are on or off) but can get dirt/moisture in the socket due to tires throwing water/dirt under the fender. Check/clean the socket contacts.

With headlights flashing, not just tail/brake and front and side blinkers, you may have another issue like two circuits shorted together. As CJ said, the headlights shouldn't be connected to any blinker circuit going through a flasher unit. To help isolate the problem circuit, you could try removing one light at a time and see if the "all lights flashing" problem goes away. Unplug one headlight and test. Then plug that one back in and unplug the other and test. Unplug one blinker and test, then another. This process of elimination procedure should help you discover at least which circuit is the issue. Then you can focus on determining a root cause.

 

[NotTJ]

I noticed two flasher modules on my fuse box. One is for hazard and one for turns?

 

[CJ]

I noticed two flasher modules on my fuse box. One is for hazard and one for turns?

Yes, this is from the 1979 FSM (same as 78) -->> 1979 Complete Technical Service Manual - CJ5 CJ7 Cherokee Wagoneer Truck

 

[BrockGrimes]