Headlight confusion (1 Viewer)

[91Cruzaa]

I need some headlight gurus to chime in. My headlights went out at the same time . I checked the fuses and they were blown. So I replaced those fuses and still nothing. I then checked out the relay, I hear it clicking. So that’s not the problem. I swapped out the headlight bulbs (inner ones) with the 9006 bulbs. And still nothing. Any suggestions help !

 

[Rusty Marlin]

Do you have a multi-meter? You will need one, and alligator clipped extensions.
See if you have voltage at the fuse. That will tell you which side of the fuse box has the problem.
From there isolate the circuit via the various harness plugs and check continuity between the ends of the plugs and confirm no short to ground. Eventually you'll find the offending wire that is either broken or shorted or quite possibly both.

Do you have any aftermarket lighting, relay triggers or anything else tied into the factory wiring? They only problems I have ever found with wiring were the result of non-factory taps and junctions.

Please download the free Wiring Schematic for your year from the reference file.
It will provide you the same instructions and much better detail.

You will want to make a copper test plug that fits into the plug sockets. They are easily made from a peice of #10 copper wire, a hammer and file. The hammer is to work harden the probe against an anvil shaped object before filing to shape.

 

[jonheld]

I need some headlight gurus to chime in. My headlights went out at the same time . I checked the fuses and they were blown. So I replaced those fuses and still nothing. I then checked out the relay, I hear it clicking. So that’s not the problem. I swapped out the headlight bulbs (inner ones) with the 9006 bulbs. And still nothing. Any suggestions help !

From the 1991 Toyota EWD: This is slightly different from later 80 Series as far as ground paths are concerned.
In any case, it should be pretty easy to find the issue with a meter.
I find it odd that both 15 amp headlight fuses would pop. That indicates a direct short to ground on both sides of the truck, or upstream of junction E2.

 

[Rollinns]

Check all the stuff mentioned above, but just because a relay is clicking doesn't always mean it's good. They could test fine (pass continuity tests and possibly pass voltage drop tests) and fail under load. I've disassembled failed relays in the past to see why they failed and they've had burnt contacts and / or broken parts. If you remove it and shake it and hear loose parts, those parts might cause a short as described above.

You said both headlights went out at the same time - In the diagram above, both are :
1. Powered by the same fusible link.
2. Powered by the same relay.
3. Share the same grounds.
4. Go through the same headlight switch.

The fusible link likely powers other things as well, have you tested those other items?
If everything above is checked and good, then I'd look for a chaffed / melted wire that's shorting somewhere.

Also, this is likely not the issue but since you're in there, now is a great time not just to check & clean grounds, but to add grounds if needed.

Please post pics of what you find.