Head lights issue - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Swedchevy67 · 10-31-2019, 12:54 PM

Just bought a 6 cylinder 1969 C10 and it’s on it’s way to Sweden now.
The seller told me that the headlights doesn’t work. He’s been driving the truck with only the parking lights on for many years.
So what would I look for at first? The ground or ?
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Barnfind46 · 10-31-2019, 12:58 PM

Could be grounds,headlight switch or dimmer switch.

**Stocker** · 10-31-2019, 01:09 PM

^^^ Yeah, a basic VOM or just a simple test light will work. Check grounds at the headlamp connectors, check voltage from the fuse block to the HL switch to the dimmer switch (these are prone to failure) and then to the connectors.

Swedchevy67 · 10-31-2019, 01:25 PM

Quote:

Originally Posted by Stocker

^^^ Yeah, a basic VOM or just a simple test light will work. Check grounds at the headlamp connectors, check voltage from the fuse block to the HL switch to the dimmer switch (these are prone to failure) and then to the connectors.

Informative suggestions
Great 👍
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smoked68 · 10-31-2019, 01:31 PM

Had same issues. The dimmer switch, probably the dimmer switch. After many hrs, it was that darn dimmer switch...

Swedchevy67 · 10-31-2019, 01:34 PM

Quote:

Originally Posted by smoked68

Had same issues. The dimmer switch, probably the dimmer switch. After many hrs, it was that darn dimmer switch...

Then I will look at the dimmer switch the first I do after the ground check
Thanks
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OregonNed · 10-31-2019, 06:40 PM

And then an upgrade to headlight relays would be good - made a world of difference for mine. They can be made or purchased. My kit was very easy to install.

**AussieinNC** · 10-31-2019, 07:57 PM

Make sure the headlight units themselves work first then check grounds, then check power supply to the lights when the switch is on....

Check fuses

Andy4639 · 10-31-2019, 10:18 PM

I just pulled a wiring harness out of my daughters 68 step. There are head light ground wires on both lights to the radiator support. Then I would check the lt- blue wire to dimmer switch it feeds it from the headlight switch. See if it has power. If not it's in the h/L switch are the red wire feeding it which is in the bundle of wires under the dash. It's a factory solder joint that is just taped up in the harness.
If you do have power then hook it back to the dimmer switch and see if it's working. Either way that's where I would start looking.

Swedchevy67 · 11-01-2019, 12:22 AM

[QUOTE=OregonNed;8619337]And then an upgrade to headlight relays would be good - made a world of difference for mine. They can be made or purchased. My kit was very easy to install.
I also bought
28 Circuit Classic-Plus Customizable 1967-72 GMC / Pickup Truck Chassis Harness P/N 10206.
Hopefully there some relays in it.
Thanks
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Swedchevy67 · 11-01-2019, 12:24 AM

Quote:

Originally Posted by Andy4639

I just pulled a wiring harness out of my daughters 68 step. There are head light ground wires on both lights to the radiator support. Then I would check the lt- blue wire to dimmer switch it feeds it from the headlight switch. See if it has power. If not it's in the h/L switch are the red wire feeding it which is in the bundle of wires under the dash. It's a factory solder joint that is just taped up in the harness.
If you do have power then hook it back to the dimmer switch and see if it's working. Either way that's where I would start looking.

Great information. Thanks

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10-31-2019, 12:54 PM	#1
Swedchevy67 Registered User Join Date: Apr 2016 Location: Stockholm Posts: 273	Head lights issue Just bought a 6 cylinder 1969 C10 and it’s on it’s way to Sweden now. The seller told me that the headlights doesn’t work. He’s been driving the truck with only the parking lights on for many years. So what would I look for at first? The ground or ? Posted via Mobile Device

10-31-2019, 12:58 PM	#2
Barnfind46 Registered User Join Date: Aug 2014 Location: Mena,Arkansas Posts: 485	Re: Head lights issue Could be grounds,headlight switch or dimmer switch. __________________ 68' with no bells or whistles unless I add'em.

10-31-2019, 01:09 PM	#3
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,728	Re: Head lights issue ^^^ Yeah, a basic VOM or just a simple test light will work. Check grounds at the headlamp connectors, check voltage from the fuse block to the HL switch to the dimmer switch (these are prone to failure) and then to the connectors. __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

10-31-2019, 01:31 PM	#5
smoked68 Registered User Join Date: Oct 2006 Location: Rock Hill, SC Posts: 421	Re: Head lights issue Had same issues. The dimmer switch, probably the dimmer switch. After many hrs, it was that darn dimmer switch... __________________ 1968 chevy shortbed, Dark Shadow Gray 4 bolt 383 Stroker,Weiand Super Charger, disc brakes, 9 inch, 391 gear, 20" Eagle wheels, muncie 4 speed/ Hurst shifter, 4/7 drop, Hedman midlengths, 3 inch exhaust w/ 2 chamber flows. 1966 Mustang with 306 roller, c-4, 9 inch Detroit locker rear. 1965 Fastback Mustang w/347 stroker, top loader 4spd, 9 inch detroit locker. 1966 Mustang coup, 306 roller, c4, 9 inch. 65 Cobra, 427, T6oo, 9inch, of course. First gen Hayabusa, airbox mod and running 2 exhaust cams.. Zoom Zoom Zoom

10-31-2019, 06:40 PM	#7
OregonNed Registered User Join Date: Dec 2012 Location: Vancouver, Washington Posts: 1,644	Re: Head lights issue And then an upgrade to headlight relays would be good - made a world of difference for mine. They can be made or purchased. My kit was very easy to install. __________________ 1968 Chevrolet C/10 LWB - 327, TH350 - 4/5 Drop

10-31-2019, 07:57 PM	#8
AussieinNC Moderator Join Date: Jun 2017 Location: Cherryville, NC Posts: 2,204	Re: Head lights issue Make sure the headlight units themselves work first then check grounds, then check power supply to the lights when the switch is on.... Check fuses __________________ Family and country before all others... 2006 Chevy Silverado (Daily Driver) 2012 Chevy Equinox

10-31-2019, 10:18 PM	#9
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: Head lights issue I just pulled a wiring harness out of my daughters 68 step. There are head light ground wires on both lights to the radiator support. Then I would check the lt- blue wire to dimmer switch it feeds it from the headlight switch. See if it has power. If not it's in the h/L switch are the red wire feeding it which is in the bundle of wires under the dash. It's a factory solder joint that is just taped up in the harness. If you do have power then hook it back to the dimmer switch and see if it's working. Either way that's where I would start looking. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

11-01-2019, 12:22 AM	#10
Swedchevy67 Registered User Join Date: Apr 2016 Location: Stockholm Posts: 273	[QUOTE=OregonNed;8619337]And then an upgrade to headlight relays would be good - made a world of difference for mine. They can be made or purchased. My kit was very easy to install. I also bought 28 Circuit Classic-Plus Customizable 1967-72 GMC / Pickup Truck Chassis Harness P/N 10206. Hopefully there some relays in it. Thanks Posted via Mobile Device



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