Headlight Circuit Issue. Ideas? (1 Viewer)

[andersonoverland]

I just spent months restoring the first of two FJ80’s and I just have a few small issues. I have no headlights, high or low beam, but I have blinkers (right blinker blinks really fast), and I have brake lights. I changed a headlight relay recently in the fuse box because before the restoration began I was actually getting high beams with no low beams but also had the right side blinkers blinking super fast. Just bought it about 6 months ago and immediately started on the engine. No idea what the guy before me did. I took apart the entire front end and redid all plugs because he had some in the wrong spots. Thought that would fix my issues along with the new relay, but now no headlights at all.

Any ideas? REALLY APPRECIATE everyone on here and your insight!!

Joey

 

[CharlieS]

Blinkers super fast is often a blown bulb on the other end of the car.

The headlight could be all kinds of things, but I'd start with checking the grounds.

 

[andersonoverland]

Blinkers super fast is often a blown bulb on the other end of the car.

The headlight could be all kinds of things, but I'd start with checking the grounds.

I’ll check that. Thank you!

 

[jonheld]

Turn signals and brake lamps are separate from the headlight circuit and have no interaction.

All 4 headlight bulbs are fed from the same relay and L/R side fuses in the relay box on the left fender.
Low beams have a hard ground to the body on the inside of the fenders.
High beams are a switched ground through the stalk.

 

[andersonoverland]

Turn signals and brake lamps are separate from the headlight circuit and have no interaction.

All 4 headlight bulbs are fed from the same relay and L/R side fuses in the relay box on the left fender.
Low beams have a hard ground to the body on the inside of the fenders.
High beams are a switched ground through the stalk.

I wonder if it was the relay I switched out?

 

[CharlieS]

Turn signals and brake lamps are separate from the headlight circuit and have no interaction.

All 4 headlight bulbs are fed from the same relay and L/R side fuses in the relay box on the left fender.
Low beams have a hard ground to the body on the inside of the fenders.
High beams are a switched ground through the stalk.

I just recall forgetting to reattach the ground wire to the inside of the fender in the engine bay by mistake and my headlights didn't work. Must've been the low beams. I don't recall. Maybe more since I run the Slee headlight harnesses.

 

[tech_dog]

If you had high beams but no low beams there must be a problem with the low beam +12v leads, bulbs or grounds. The high and low beams work off +12v from the same relay, and the low beams are supposed to have a hard ground.

The stalk light switch turns on the parking lights, then the main headlight circuit.

There's a separate headlamp dimmer switch that gives the high beams their ground. It's activated by the stalk switch clicking forward or back, but it's a separate switch with separate wiring connections.

I'm working a similar problem and gathered wiring info here: High beams will flash but won't stay on - anyone know how the switch works? - https://forum.ih8mud.com/threads/high-beams-will-flash-but-wont-stay-on-anyone-know-how-the-switch-works.1352445/post-15752583

 

[andersonoverland]

Wow! Sweet! Great info!! Thanks!!

 

[andersonoverland]

So now low beans work but no highs. Loose plugs fixed, but not sure why high beams don’t work still. New bulbs, checked grounds, maybe switch in steering column?

 

[tech_dog]

So now low beans work but no highs. Loose plugs fixed, but not sure why high beams don’t work still. New bulbs, checked grounds, maybe switch in steering column?

If your headlamp stalk switch doesn't click forward and back as it should, the problem is in the bracket, spring, and bearing indicated by the red arrow in this pic.

If your headlamp stalk switch clicks forward and back as it should and you don't have high beams, check the headlamp dimmer switch as described in the post I linked above. The image below shows the headlamp dimmer switch being removed from the back of the switch assembly. The plunger goes into that hole, and presses up against the underside of the stalk switch.

If you can short the headlamp dimmer terminals as I did in the other post, and it activates your brights, you know it's the headlamp dimmer switch.