Troubleshooting a weird issue (at least it’s a new one for me).

1. Turn headlights on, left turn signal indicator light illuminates and stays on.
2. Driving lights, Brake lights, and turn signals operate properly.
3. Hazards work in the rear and the fronts “work” but not together. They alternate side to side…..?

Going to replace the hazard module and double check the grounds, just figured I’d see if anyone has seem anything like this before.

 

Year, model, and stock or modified wiring? FYI, if the turn signals flash at all, the flasher module is not the problem. What is the behavior with the headlights off vs on?

 

Sorry, didn’t think make/model mattered but it’s a 72 442 convertible. Stock wiring.

I swapped the hazard flasher module and it cured the funky side to side hazard flashing.

Everything functions properly now except that the left turn dash indicator lights solid when the headlight switch is pulled out (in both parking and headlight positions).

 

There is a bad ground at one of the left turn/park sockets. The turn signal filament is grounding through the parking light circuit with the lights off, but once the lights are on there's 12V on the park light circuit and the turn signal can't ground.
And sorry, but a two-prong flasher module physically can't cause the lights to flash side-to-side. That wiring is in the turn signal switch. The flasher module just switches power to the turn signal switch on and off. Something else caused it that either got "fixed" inadvertently when you changed the flasher or is an intermittent problem that will come back.

 

Did you run across one of these?

 

Haha! That that must be the one!

He was running side to side pushing the ground wires….then left when he heard me swap the flasher modules.

Definitely need to check all of the socket grounds.

Thanks for the replies!

 

I have seen a few 1157 bulbs short internally and cause similar problems.

 

NTXOlds, That was EXACTLY what I was thinking!!!!

 

Gotta have a little fun every now and then.