Pull head light switch '78 FJ40 (1 Viewer)

[BossHogg]

Help - no head lights when I pull the light switch to the second position. The first position is for the parking lights and all are working. When I push the turn signal lever forward, the bright lights work. Any ideas on where to start? The 15 amp fuse looks OK.

 

[brian]

both lights dead or the switch gone.

 

[fj401978]

Check your ground wires...funky thinks always happen when ground wires are loose or there is corrosion under the connections. It happens frequently on these old '40s. Rust is our enemy, but our constant companion.

 

[bj40green]

So, in first position you have running lights, correct?
In second position you have High Beam with the stalk in the forward position, right?
In second position you don't have Low Beam with the stalk in the backward position, right?
It's not the headlight switch.
It's not a ground problem because the High Beam works and they have a common ground with the Low Beams.
Do have signal/flash when you pull the stalk towards the steering column? Yes/No?

1. Both bulbs have burned out low beam filaments
or
2. Dimmer switch is bad or wiring problem.
or
3. Is the head light circuit modified with relays? If so, the Low Beam relay is defective or bad wiring/contacts.

Rudi

 

[Fast Eddy]

It's pretty easy to measure the voltage at the headlight plug for the various cases and the resistance of the two bulbs themselves.

 

[bj40green]

If your light bulbs are OK check for voltage on HL (Head light Low Beam) terminal.


Rudi

 

[Shark56]

My guess is: Inside dimmer/turn signal switch is the contacts for the lights. They are either dirty or misaligned If you pull the column cover off you can see the contacts and how the work when the switch is pushed or pulled. I had a something simuliar with the high beams not working. Had to clean those contacts with electrical cleaner.

 

[BossHogg]

Thanks for the great responses. New (used ) light switch installed and still no low beam. New seal beam installed - no change. Lights will flash when stalk is pulled towards the steering wheel. High beams come on when light switch is in second position and stalk pushed forward. Next step is to have the HD to HL terminal connection tested.

Rudi -great wiring diagrams. What manual is this from and is a copy available for purchase?

 

[bj40green]

My guess is that you need to inspect the Hi-Lo beam and turn switch.
Seen from above you see the horn contact


Seen from the bottom. The turn switch is on the right, the Hi-Lo switch is on the left.


You'll find the problem here. This is the High/Low/Flash switch


Rudi

 

[ckrustware0045]

Excellent thread, especially bj40green's post. I had the same problem ; removed the switch and cleaned up the decades of grime in there , hit the contacts with emery cloth , cleaned up both the pigtail's contacts , and it works on 2 test drives. If it acts up again I will replace the switch. Hardest part is putting the steering column covers back on. Of course , I PB blasted all the bolts.

I used the following thread for guidance on steering wheel removal.

https://forum.ih8mud.com/threads/steering-wheel-removal.499231/

I marked the steering wheel and steering column with a paint marker to know exactly where the splines lined with steering wheel.