90 gmc sierra 1500 electrical problem

[ducorse]

i have had this truck for a long time and have never had much problems with it but this is driving me nuts. here is the story

I had the radio on, and i turned on the headlights and suddenly this is what went dead: headlights, radio, and dash lights.

i turn off the headlight switch, and after a moment, i heard a click and the radio once again got power. i turned on the headlight switch and everything dead agiain. after a few tries, everything stayed dead until....

next morning clock on radio had power again. pressed power to radio (headlights off) and radio and all others went dead again.

later clock had power again.. turned on and off headlights and heard clicking from radio amp under dash near steering column.

next day all working well both headlamps and radio..

later evening all fails. press power on radio and hear clicking from amp (headlight switch off)

any ideas folks? just for reference, normally when you turn on headlights, the clock/radio dimms. my best suspect is the amp that is making clicking sounds, but i have not replaced it becase i have yet to secure a replacement for it, but i have removed it, and the headlights still do not work. it seems like there is some relay that controls headlights and dimms the radio and turns on the dash lights but i cant find it.

also, you dont have to tell me to look for a short, thanks in advance.

[gmctrucks]

If it's the factory Amp buy one from a Salvage yard see what happens buy a Hanes manuel see if the Radio somehow is tried into the headlights it just might be the radio. Hope this helps!

[ducorse]

thanks gmctrucks for the help.

actually it wasn't the amp as i had thought. it is kinda funny actually.

i took out the headlight switch and of course there was no power coming from the female adaptor socket. i was using one of those lighted voltmeter things and i stuck it into the adaptor while i rummaged around helplessly under the dash -- and in the process i pretty much took my whole driver's side dash all apart.

then i went over to the glove box on the passenger side and when i pushed on it my voltmeter flickered. i pushed the door more and more flickering. i then took out the inside of the glove box and i found 2 red wires plugged together with a clip connector that was loose i just unplugged and plugged it back in and everyting lit up!!

basicly the wire was the connection between the fuse block on the front of the firewall to the mess of wires under the driver dash. that wire fed all of the prevously mentioned items.

you might call me lucky rather than good.
now i gotta put all this **** back together!

[gmctrucks]

Glad it fixed the problem I up-dated my speakers on my Ext-Cab 93 truck boy did it make a big change im running a Bass cannon under the back seat just for my lows no real banging don't like that and im using the other speakers for highs it sounds real good im thinking of replacing the head unit with a Kenwood that my wife bought me but I have never got around to it what I really did is install it on my 87 Surburban with three Amps I have tweeters up front on the dash 6x9's where the factory speakers were in the middle of burb then a MTX sub in the very back it sounds GREAT im selling it and im wanting to install the electronics in my truck but im lazy that's the truth I might get my son to do the work someday, I just posted my Suburban today for sale it's in fair shape 5.7F.I. doesn't burn no oil trans shifts perfect 4X4 works this truck will make it anywhere with no problems that's how much I trust it. Take care! gmctrucks