The Stovebolt Site Forums The Shop Area General Truck Talk No headlights!

All,

I was out this afternoon at a local park just before dusk and parked in front of the park's gymnasium. I could see a reflection of the front of my truck in the glass front doors so (for whatever reason) I decide to pop on my headlights. No lights! :confused:

I was waiting on my wife and kids to meet me there from the Mickey-Ds nearby but decided to head back home. I was certain that the flasher was bad and replaced it. Still no lights. :confused:

Last time I ran the headlights was a couple of months ago. Never a problem with the lights, but the light switched I bought from Chevy Duty three or four years ago has always been flimsy, and seemed to have some sort of short it in, as the dash lights would usually "blink off" as you turned the switch from 'Parklights' to 'Headlights'. By the way, the park lights and taillights work fine. So does the signal lights and brake lights. The headlights are the only thing not working. :confused:

One more thing to note - the dimmer switch was incorrectly installed by a previous owner. When the lights were on dim, the "Bright" indicator would be on and vice versa. Never really caused a problem in the past.

Now the dimmer switch indicator stays in the "Bright" position. I figure the problem has to be either the dimmer switch or the light switch. What's the best way to eliminate each one?

-ftyler

Pull the wires from the dimmer switch and jump around the switch to see if the headlights work or not. I've seen a lot of dimmers go bad because of there location on the floor. I've had the harness connectors melt and lose connection at the dimmer also,
That's where I would start,
Scott

See if the loom has come unplugged

I'd wager a coupla bux on the dimmer switch. I've had several of them fail on me like that. Once I had one in a 67 Camaro just quit while driving down the street with the lights on. The cop behind me noticed it, too.

Luckily, I stomped on it a couple of times and got the brights working just as he was coming up to my door after he'd pulled me over. I explained what happened and he just suggested that I get another switch before I went out for any more night time drives. I went home and swapped the switch out the next day and never had any more troubles with that car. Matter of fact, I just sold it a few months ago....we had 2 67s and a buncha medical bills, so one of them had to go. Oh...the lights still worked fine when I sold it.

A lot of the repop headlight switches you can get for the older cars/trucks are built in China (surprise!) and there have been a few that I've heard about in the past with faulty breakers in the switch that will short out and never come back to life.

That the high beem indicator is on says to me that the dimmer switch is the problem this time.

Someone suggested taking it out and jumping around it. I'd try that approach to confirm its the problem.

The dimmer switch it is - I'll start there (and now that I think about it will probably finish there too).

Thanks guys!

-ftyler

**** UPDATE ****

Still no headlights! :mad:

Since the last post I've replaced BOTH the dimmer switch and headlight switch. Still the lights don't work. Same symptoms.

Interior dome light works, park lights work, interior lights work (albeit sporatically). Should I now just consider replacing the entire underdash harness? There seems to be nothing else left to do (other than check the sockets at each headlight bulb to ensure electrical continuity - am I'm both headlights did not burn out together; dim and bright).

-ftyler

Check the grounds at the headlights.

How much of an electrician are you? Do you have a schematic for the wiring? How about a voltmeter? (Always measure for voltage with one lead attached to where you think the voltage should be and the other to ground. To be sure, go for a battery ground even if you have to run a wire to the negative post of the battery.)

Don't have a voltmeter? Use a spare light the same voltage as your system (12V or 6V) and use it to see if you have voltage. If you have a spare socket to put it in, just add some length of wire to the wires for test leads, or if you dont have a socket you can solder wires to the base and casing. Use a small light, like a tail or turn lamp or something, not a headlamp. Don't want to blow fuses if you test a low current circuit.

Unplug a headlight, turn on the switch and see if you get voltage across the high to ground sides of the headlamp socket. No voltage? Try measuring from each lug of the socket to the battery negative. Voltage now? Definitely a grounding issue.

Try tracing each wire from the headlamp socket to see where it goes. Two should come from the dimmer switch. One should go to a ground somewhere. (Bolted to a fender or something.) Try disassembling the ground and cleaning it up until you have shiny metal on the wire end and the connecting spot on the body or frame.

Got a good ground and no voltage? Go back to the dimmer switch (with the headlight switch still on) and see if you have voltage on the two terminals coming out of it. No? See if there is voltage on the wire going into it. No? Trace that wire back. Should come from the switch. Measure for voltage out of the switch.

With all you've tried, I'd bet it's a bad ground.

Sounds like a bad ground or a disconnected/broken wire.

Thanks guys. I didn't even think about the grounding. I'll bet it's that or a disconnected wire. Headlight switch must be good - it controls the park lights and interior lights and they all work fine. As a matter of fact, the old dimmer switch and headlight switch were probably ok too. Now I have a spare of each.

If it's not a grounding or cut/disconnected wire I'm burning the truck. Anybody want a 292?!?! :p :mad:

-ftyler

Don,t burn it yet. If thats the biggest problem you ever have with it you are real lucky. Get a test light & start traceing it down. If there is no curent at center term. of the dimmer switch check the large red wire at the headlight switch.

I like my 292,s well done.
Jbennett
40 burb

Between the time I bought the truck in 2000, through 2003 (after the addition of 2 young'uns), I've done the following to this truck.

- Replaced all wheel cylinders
- Had rear axle bearings replaced.
- All wheel seals replaced
- New brake lines and hoses in front.
- New radiator
- Changed rear end fluid
- Small cosmetic stuff (glove box, door rubber seals, miscellaneous lenses and hoses, etc.)
- New seat belts

In August 2003,

- installed 292 (with new everything) and rebuilt manual overdrive transmission
- new starter
- new clutch, pp, tob, U-joints (front & rear) etc.
- headers and complete new aluminized exhaust system all the way back
- went to 1-wire alternator (new) system, in place of the old voltage regulator

Since then,

- new engine wiring harness
- new battery terminals
- new wiper blades & arms

Replacing the bedwood and hood (both of which I already have) were two of my goals for this year, along with a couple of rocker patch panels welded in. Believe it or not all the other repairs were no brainers and relatively easy to do - even the new engine/tranny. I hate electrical problems. I guess I've never gotten over having to replace all the wiring in my first car 20 years ago (a 1973 Toyota Corolla )!!

-ftyler

Found the problem (or more accurately I'm in the general vicinity).

Being the only person on the bolt who would let a small truck related problem get to him such that he'd go outside in the icy driveway on a cold, dark night, I had to continue looking. :p I started fumbling with some wires between the grill and grill panel - I just turned the light switch on and started moving the wires seeing if anything happened. BINGO! Lights!! Hold it in a certain position - lights on; let it go - lights off.

So at least I know I can rewire this area and have lights. Besides the underdash main harness this was the ONLY other wiring on the truck that wasn't new! :rolleyes:

-ftyler