History:
I got this truck 1 year ago. About 6mnths ago my "park/marker lights" would not work unless I smacked the dash and that was not 100%. I broke down the switch, changed it etc and realized there was a burn mark on my headlight switch wiring harness behind the dash and some of the connections were loose. I bought replacement harness from dealer and wired it up. WALA all lights worked for about 1-2mnths and now my headlights don't work at all. Fuses look good, I talked to dealer and read some posts so as a result tonite i picked a multifunction switch from Advance Auto. Did the work right in their parking lot and no fix. Help me understand what other things could be making my headlights fail. By the way my high beams work 100%

 

first check the bulbs, I have seen people have one go out and not notice it till the other one goes out and they would come in and say "my headlights just quit when in all reality they were just burned out.

 

Did that and bulbs are fine. Purchased 2 new ones when started having the problem,. I'm reading some posts here from 2003 and wondering if my vehicle has this part called a "Lamp Out Module" behind the dash. i'm goin to link into a parts store site and check.

 

No. Doesnt look like it has a LOM per the parts websites.

 

Take a pic of how you spiced the new connector into the harness.

 

What kind of bulbs did you get? I got a set of crappy fake xenon HID bulbs and ,y head lights stopped working, put in the stock set and it worked great

 

I used mid grade Silverstars in the Grey pack. I think they are 1 down from the brightest option.

 

I'm gonna run out now double check the fuses then run to walmart and get the bottom line standard bulbs and see what happens. If still no go then I'm defeated. I think.

 

there could be a short in the headlight wiring harness... its known to happen. I would use a circit tester and see where you have power. If theres power at the plug for the bulb then it could be the bulb. If theres power at the switch then i could be the switch. If theres no power at all you could have a bad ground. Theres a bunch of things to look into

 

Ok def not the bulbs.. Not a fuse. I pulled the headlight switch out of dash. The switch is only few months old replaced it when I replaced the wiring harness. I grab several harnesses under the hood and kinda shook them while tryin to see if a headlight jumped on intermidantly and no go. I checked the bulb plugs and they look good. I do notice that there are 3 plugs running from each light. A green, a black and a red. Which wire does what? I thinkin blk is ground and if that was bad then I probably would not get high beams (amatuer opinion there). Damn and i really wanted to see tonight.

 

I'm down to 3 things.

1. I've been reading posts and it looks like this 93 250 does not have a relay controlling headlights, Correct?

2. I know the guy I bought truck from did use to use it with a plow setup but i drove it for about 8 months with no problems w headlights. Could the old plow set up have anything to do w this?

3. Last but not least I do have a multimater that I plan to check for power at each headligth socket and I will pull te headlight switch and probe for power there BUT what I don;t know is waht setting to have the multimeter on and what I am looking for.

Any help?

 

have any extra switches that might have been for the plow lights that got flipped? look along column for spliced wires from the dimmer switch, just throwing ideas, as far as the multi-meter set it on dc volts and look for power. a test light would be easier probably.

 

Ok. Just went out to truck and double checked all fuses even if they looked good. Took the relays in the engine fuse box and switched around. No luck. Put flashlight into foot well and looked for anything burnded out or funny lookin.. Looked to see where ther Red/Blk wire comes into firewall. Pulled switch and played with wires. Nothing. Once I put test ligth on it I assume if there's a problem it would be at the switch rather then each light socket. Since the switch powers both low's through 1 wire.