Headlight problem


thecackster
04-12-2008, 04:12 PM
Last night I go to a friends house, headlights working fine. Come out and i turn them on, no lights and a squeaky buzzing noise is comming from under the dash, when I remove the RLY 2 Omron 12077866 D00 relay? it stops buzzing and and still have not headlights..... any help would be great. thanks.

edit: did a little reading and it's the headlight relay. but i bought a new one, put it in. same buzzing noise...

another edit: It still has no headlights but when I pull back on the high/low switch, when in high position it does not make the noise. ... if that helps out any.

777stickman
04-13-2008, 09:47 AM
Does your truck have the DRL (Daytime Running Lamp) system? Also do the high beams work?

Grandslam8
04-13-2008, 11:25 AM
My 97 suburban has a simuliar problem, DSL work like they always have, any time the key is on and the parking brake is not activated except when the light switch is in the headlight position. They work when the switch is in the off position and in the 2nd or parking light position, but when I turn the switch to the 3rd or the headlight position the only thing burning is parking lights, I have cycled the high / low beam switch and still nothing. I replaced the light switch about fifty bucks still the same results. Anybody got any ideas ?

Sorry that should be DRL instead of DSL.

thecackster
04-13-2008, 12:14 PM
um it is equipped with a DRL system, but it has never worked. The green light on the dash is on but I've never had the lights on. Also the high beams do NOT work. It just makes the buzzing noise stop when engaged.

bubba99
04-13-2008, 02:21 PM
I'm staring at the schematic for a 98 headlight circuit. The feed for both the hi and low beam comes through the DRL module. The factory manual states it is taped to a wiring harness under the left side of the inst panel. I would give it a good sniff test before wasting money on a new one. There is also a protective diode (203) in series with this feed before the DRL relay. It is part of the wiring harness "at RH of steering column support". I have not got a clue what it might look like. Probably a small plastic enclosure similar to one of those add-on fuse holders. It should be cheap.

thecackster
04-13-2008, 03:20 PM
I'm staring at the schematic for a 98 headlight circuit. The feed for both the hi and low beam comes through the DRL module. The factory manual states it is taped to a wiring harness under the left side of the inst panel. I would give it a good sniff test before wasting money on a new one. There is also a protective diode (203) in series with this feed before the DRL relay. It is part of the wiring harness "at RH of steering column support". I have not got a clue what it might look like. Probably a small plastic enclosure similar to one of those add-on fuse holders. It should be cheap.

I did read about the diode... I have no clue what it looks like. I unplugged a few things downthere and tried it but i'm not sure it helped. I read that if unplugged the high beams should work.

Grandslam8
04-13-2008, 03:28 PM
Just took a look under the dash on my 97 and I don't see either, A little pushed for time this afternoon will try again when time permits, Thanks for your help bubba99.

777stickman
04-14-2008, 07:49 PM
Check the "LIGHTING" 50a fuse #8 in the underhood fuse block. Check for power on the yellow wire at the dimmer switch with the head lights on.

Diode 203 is in-line with the DRL power feed from the DRL-FOG fuse in the I/P fuse block for the DRL's only and has nothing to do with the headlights working when the headlights are turned on.

As far as the DRL module. Does the DRL dash light go off when you turn the headlights on?

Does the high beam dash light come on when you switch to high beams?

thecackster
04-14-2008, 11:38 PM
50 A is good i'll have to check the power tomorrow in the day and i have to buy a light meter... and no the DRL light isn't on when the lights are off.... that probably is a key to something. and no the brights indicator isn't on when i have the lights on and the brights engaged.

777stickman
04-15-2008, 10:05 AM
um it is equipped with a DRL system, but it has never worked. The green light on the dash is on but I've never had the lights on. Also the high beams do NOT work. It just makes the buzzing noise stop when engaged.

I'm a bit confused. In this earlier post you said the green DRL dash lite was on and in the last post you said it wasn't?? Make sure the parking brake is not set as it will disable the DRL's.

If you have power to the dimmer sw, replace it. If no power it could be the lite sw or the DRL module or wiring.

thecackster
04-15-2008, 06:28 PM
I'm a bit confused. In this earlier post you said the green DRL dash lite was on and in the last post you said it wasn't?? Make sure the parking brake is not set as it will disable the DRL's.

If you have power to the dimmer sw, replace it. If no power it could be the lite sw or the DRL module or wiring.

It was on before this happened but the DRL's never worked. Parking break is not set as well. I still can't explain the weird buzzing noise coming from the headlight relay.

777stickman
04-15-2008, 07:12 PM
OK. 1st of all there is no "headlight relay" in the system that I know of. There is the DRL relay located at the bottom center of the "convenience center". Is this the one you're talking about?

The DRL module supplies ground signals for the DRL relay and the green DRL dash light. You still need to check for power coming out of the lite sw to the DRL module and to the dimmer sw, all on the yellow wire.

From what you've said I would suspect the DRL module or wiring.

Grandslam8
04-15-2008, 07:17 PM
Check the "LIGHTING" 50a fuse #8 in the underhood fuse block. Check for power on the yellow wire at the dimmer switch with the head lights on.

Diode 203 is in-line with the DRL power feed from the DRL-FOG fuse in the I/P fuse block for the DRL's only and has nothing to do with the headlights working when the headlights are turned on.

As far as the DRL module. Does the DRL dash light go off when you turn the headlights on?

Does the high beam dash light come on when you switch to high beams? Sorry I hitched a ride on this post, We seemed to have a simliar problem. When I turn my light switch to the headlight position with the key on my green DRL indicator light goes out and my high beam light doesen't work when I switch from low to high beam. The 50a fuse under the hood marked lights is good. I am open to suggestions. Any help will be greatly appericated.

thecackster
04-15-2008, 11:01 PM
We'll i figured out what it was today. I was leaving class tonight around 9 and it was dark, i was mad cuz i didn't have headlights to drive home with.. I just hit the dash near the light switch and bam headlights... so I think it's a poor connection in that switch. I'll take it appart this weekend and see what I can do .... I don't get why the DRL relay was buzzing. and yea it's the center relay on the bottom of the convience center. I noticed that I no longer have the green DRL indicator is not on anymore, and last week i know it was working.....

Fire3501
10-18-2010, 07:25 PM
My headlights went out tonight.

1996 Chevy P'up

No DRL or low beams.

High beams do work.

Relay 12077866 beside flasher clicks and buzzes when I toggle headlight switch.

Help!

Thanks.

corsair-pilot
10-18-2010, 11:09 PM
Hi all.

Look at diagram and you will see drl module will not kill headlamps.
The diodes are to drop the voltage for the drl. They are dimmer than standard low beams, the two diodes drop the voltage .7 volts each.
But you found the switch bad, I bet you will find burnt switch and harness terminals.
Dale

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