headlights won't work

[dixiethecustomcamper]

Hey everyone, looking for a little help. my headlights will not turn on when I pull out the light switch. This just happened recently. Prior to this the truck always had finicky lights and sometimes they'd go off if you put the high beams on. This also worked the other way as you'd turn the lights on and they stayed off, but press the high beam switch and they'd come on. having no headlights is dangerous and being unable to drive it past about 8:30pm is disappointing. truck is a 1968 gmc custom camper 3/4 ton. I checked all of my fuses and wiring today, everything seems to be in working order... any ideas? could there be a switch somewhere that's worn out or blown? thanks!
Posted via Mobile Device

[cdowns]

check the wiring plugs at the dimmer switch // also a new dimmer switch is cheap as heck at the autoparts store

[Stocker]

x2, Cliff beat me to it. Common problem area.

[alsriv2]

I had a '69 GMC Custom Camper (Longhorn) that had the exact problem you are having with yours. Turns out the dimmer switch was the entire problem. I installed a new one and all the problems with my headlights went away.

That switch near the floor picks up lots of moisture and crap over the years and the contacts get corroded or contaminated.

[leftybass209]

I have to agree.... the dimmer switch is often the issue with these old trucks. My case was I would have low beams, but no high beams. Dimmer switch cured the issue. Remember, you're stepping on the button every time you switch from hi's to low's, and many times switching often because of the dull light output in these trucks to begin with. That's a rough life on the switch to be stepped on constantly!

If you really want to make a difference, you can add a headlight relay harness along with a new dimmer switch. it'll give you modern headlight power, and probably stop the need to constantly switch to high beams just to get some useable light, thus lengthening the lifespan of the dimmer switch.

[Custom/Ten]

Mine was the dimmer switch too. Blue is power in, brown is power out to low beams, green is power out to brights, for my 72 anyway. Pop a test light or volt meter on there if you wanna know for sure. I think mine was around 15 bucks.

[Dee72]

My headlights haven't been work they just won't turn on at all on 72 c10.I've done some research and read that it might be the dimmer switch,Can somebody help me out on how to find it so I can replace it thanks or if they know what the actual problem might be

[Stocker]

Originally Posted by Dee72

My headlights haven't been work they just won't turn on at all on 72 c10.I've done some research and read that it might be the dimmer switch,Can somebody help me out on how to find it so I can replace it thanks or if they know what the actual problem might be

Dimmer switch is on the floor near the parking brake. Since the headlamps don't work at all, I would also check the HL switch on the dash.

[franken]

Dimmer switches get dirty contacts when not used. I'd first turn on the lights then cycle the dimmer about 20 times.