92 IDI fon electrical..

Has the extended cab

So my brake/haz/turn work
I've got 3 wires, though I don't remember the hot wire color so I'll just call it hot...I wanna say it's pink or yellow.

Brown, black, and hot to the rear pass tail bulb (3157)

I didn't check volts in any state other than running lights on, didn't flip hazards or turns or brake and pull volts.

So with the running lights on; I get 12v between hot and black in the back of the pigtail... and they're on the same side inside the pigtail, where I can also get 13v...but bulb won't turn on, neither filament let alone both; I get 6v between hot and the 2 opposing sides terminals.

Just...I hate electrical. It should be on... I've bent the plugs to make sure they contact, I've tried 3 bulbs... Brake, turn, and hazard work (though I don't know that both filaments illuminate during braking).

Anyone had a similar issue they can just solve it real fast ... Kind of puzzling; I can illuminate a test light but not 3 bulbs; not even a for sure good bulb.

Are the bulb sockets free from corrosion? Put your truck information in your signature so we don't have to keep asking what year and model is your truck? Go to your name in the very top right hand corner and click on Signature and fill this information out.

I'd imagine the idi only came in the f2f3, I said 92 IDI... They're gonna have the same electronics anyway, generally the only difference between the 250 and 350 is suspension related, isn't it?

Check for bad grounds. Also have both the tail lamp and turn signal lamps on at the same time other wise it will back feed and find a ground. You have to remember that the frame is one big wire and half the circuit.

cragenj3 said:

I get 6v between hot and the 2 opposing sides terminals.

Click to expand...

What problem caused you to be investigating this ? One side of the truck works and the other isn't ?

If you are checking between the "Hot when tail-lights ON" wire and either of the brake/turn wires, you are not going to get full voltage reading; I am surprised it reads anything at all --- providing I am understanding what you are describing.

It is expected for the wire with a working bulb lit to read less than a wire with no working bulb.

Forget the multi-meter and use a test-light.

Clip it to good Ground and probe the terminals in the connector to see what you are getting there.

Am I thinking right = a 3157 is not a round-base "bayonet" bulb but a flattened glass base bulb much like a 194, right ?

If so, sockets for these bulbs are very difficult to test and diagnose as they are so confined and close together.

If your bulbs are normal big round base bulbs with a big receptacle with big fat contacts in there, like an 1157, then, with all the wires connected, probe those two contacts in the bulb socket and see what you are getting.

Sacrifice a long extension cord = cut off the ends and put Alligator Clips on the wires = a test cord long enough to reach anywhere on the truck or trailer.

Identify one of your extension cord wires as HOT and the other as GROUND

Under the hood, clip your Alligator Clips to known HOT and good Ground --- Make sure the clips at the other end can't touch each other --- drop one down in an empty plastic bottle or whatever to prevent them touching.

Now, you have known good HOT and Ground back there to determine if your problem lies within the light itself or is in the wiring.