Headlights Won't Turn Off (1 Viewer)

[JohnnyBighead]

Just picked up my first 40 and I am loving it so far. It has a few kinks to work out, but I am glad to have something to work on.

As of now, the headlights won't turn off. I currently have them unplugged, and if I need them, I open up the hood and plug them in. Not the worst process in the world, but it is getting old fast.

Do you guys think it is the switch? Not a hard fix, but just wanted to see if you guys have ever experienced this.

Thanks!

 

[Awl_TEQ]

Not a lot to go on there but I suppose it could be the switch. I would trace the wiring starting at the bulbs and work back to source and see if it's been altered. The bulbs may be drawing power from somewhere else due to a previous owner hack job. There are wiring schematics somewhere on MUD or in the FSM.

 

[CWilder138]

I'd check the connections on the switch. The hot wire connection could be bent and touching the other wires causing them to be hot all the time. If not, you probably have a hack job as Johnny said.

 

[roadstr6]

Does the switch move in and out easily when you push/pull it? It should click as you pull out. There should be some resistance. The little spring and contacts inside may be messed up but I would look at the connections on the rear of the switch first to see if you have anything touching or arcing. That is most likely the problem.

 

[inkpot]

If it is an early model, check the hi/lo switch on the floor for damage/wear.

 

[JohnnyBighead]

Sorry for the lack of info in the original post.

The switch seems to have good action and clicks in the appropriate spots... I decided to remove the know and see what was going on and this is what I saw. Any idea what that yellow wire is? Is is marked with a 7.

Thoughts?

picture share

 

[JohnVee]

It might have had aux lights that tapped into the headlight circuit via that yellow wire.

I'd check the switch. Might have to remove it and open it up. Just because it feels and sounds good doesn't mean it's so.

Pull the headlight fuse and see if they turn off. If not, then they're getting power from somewhere else through a broken wire somewhere.

What year is the truck? You'll have to search for fuse panel info if you don't have the cover. There are different layouts for different years.

 

[JohnnyBighead]

Thanks d

It might have had aux lights that tapped into the headlight circuit via that yellow wire.

I'd check the switch. Might have to remove it and open it up. Just because it feels and sounds good doesn't mean it's so.

Pull the headlight fuse and see if they turn off. If not, then they're getting power from somewhere else through a broken wire somewhere.

What year is the truck? You'll have to search for fuse panel info if you don't have the cover. There are different layouts for different years.

Thanks for this. The truck is a 73. I will try the fuse pull and see what happens.

The switch is working well in both positions for the tail lights and cluster light, so at least that is something.

 

[thebigredrocker]

So with your key removed and headlight switch pushed in your lights stay on? Or do they turn on once you insert key and turn to run?

Your excellent photo shows that the PO has "rewired". As you probably know those blue insulation displacement connectors are not Toyota. I wouldn't pull apart your switch just yet. As stated above you'll need to trace your headlight wires and figure out where they are getting constant juice and also pull your fuses one by one and see which circuit they are now on.

Here's a 73 wiring schematic on coolermans site: http://www.globalsoftware-inc.com/coolerman/fj40/schematics/FJ40/1973FJ40/73JF40.jpg

I glanced at the 73 schematic. It looks to me like a red wire should supply power from your top 20amp fuse. This should be hot all the time. When you pull your headlight switch, power is delivered via a red/white wire to your dimmer switch. Your dimmer switch then dictates Hi/Lo beam. RY & RG should come out of your dimmer and go to the headlights. I would look closely at the red/white wire. It should only be hot when your switch is pulled. With your headlights plugged back in, test it when connected to your switch and unplugged from your switch.

It also appears your headlight switch has another hot wire which should be green. It looks to come off your bottom 15amp fuse. I think this supplies power at night to your gauge cluster lights, tail lights, ect. According to the schematic, that wire also is also green.

 

[JohnnyBighead]

So with your key removed and headlight switch pushed in your lights stay on? Or do they turn on once you insert key and turn to run?

Your excellent photo shows that the PO has "rewired". As you probably know those blue insulation displacement connectors are not Toyota. I wouldn't pull apart your switch just yet. As stated above you'll need to trace your headlight wires and figure out where they are getting constant juice and also pull your fuses one by one and see which circuit they are now on.

Here's a 73 wiring schematic on coolermans site: http://www.globalsoftware-inc.com/coolerman/fj40/schematics/FJ40/1973FJ40/73JF40.jpg

I glanced at the 73 schematic. It looks to me like a red wire should supply power from your top 20amp fuse. This should be hot all the time. When you pull your headlight switch, power is delivered via a red/white wire to your dimmer switch. Your dimmer switch then dictates Hi/Lo beam. RY & RG should come out of your dimmer and go to the headlights. I would look closely at the red/white wire. It should only be hot when your switch is pulled. With your headlights plugged back in, test it when connected to your switch and unplugged from your switch.

It also appears your headlight switch has another hot wire which should be green. It looks to come off your bottom 15amp fuse. I think this supplies power at night to your gauge cluster lights, tail lights, ect. According to the schematic, that wire also is also green.

Thanks for this. I will check it out and report back.

 

[JohnnyBighead]

Quick update:

The headlights are working again and it was a simple fix. There was a bad connection on the passenger side headlight plug. Once corrected, everything worked as it should!

Thanks for all your help.

 

[scooter123]

ordered new switch from cruiser corps........as soon as I plug in either headlights come on or running lights come on in off position..........is there a trick when installing new switch?? Any help would be greatly appreciated!!!