Help!!! no low beams and dim high beams - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1966gmc · 10-29-2007, 07:30 PM

I never drive the truck at night but would like to every once and awhile.Anywhoo,I noticed a few weeks ago that my low beam light on the passenger side was dim and the driver side does not come on.If I turn on the high beams,the low beam on the drivers side will light up and is quite bright while the others are dim.I got fooling around with the passenger side tonight and now the low beams do not work until you turn on the high beams.All other lights work(tails,brake and turn signals) fine.
What in the hell is goin on? A bad ground somewhere?

Please help

**Chevy Fleetside** · 10-29-2007, 08:37 PM

Quote:

Originally Posted by 1966gmc

A bad ground somewhere?

Please help

Thats a good place to start...

**Chevy Fleetside** · 10-29-2007, 08:38 PM

Also.. Make sure the plug at the radiator support is clean. Unplug it and try to clean it.

Greg63 · 10-30-2007, 02:07 PM

I had a similar problem to yours a few years back . My highs and lows were dim all the time .
I did some research and found this solution ; I rewired the headlight circuit so that instead of the headlight switch sending power directly to the headlights , the headlight switch now sends power to a pair of relays . One relay is for high beams and the other relay is for low beams . The headlight switch powers the contactors in the relays (which draws less amperage than the headflights) and the higher amperage headlights are powered through the contacts . There is virtually no voltage loss to the headlights this way and there is less strain on the headlight switch .
I now have much brighter headlights .

jchav62 · 11-01-2007, 01:31 PM

Check the wires with a light tester and see if you're check juice there. How old are the bulbs? Maybe there just burnt out.

rodnok1 · 11-01-2007, 02:26 PM

Check the actual connections at the headlights, they get corrorded and loose over time.

Mesabooger · 11-01-2007, 03:06 PM

I had the same problem, turned out to be there was not a good ground. The grill had been repainted and non of the grill was grounding.

Cobblemizer · 11-01-2007, 05:20 PM

I had the same problem on my 63 and the wires on the high/low beam switch where corroded (years of wet boot and shoes mixed with road salt do wonders to electrical parts!)

1966gmc · 11-06-2007, 01:29 PM

Hey y'all.I finally got off my rear and found that the grounds were not in the best of shape.I did the headlight relay mod and ran a solid ground from all the lights to the neg battery terminal while I was in there.All lights are functional now yay! Now all I have to do is invest in some halogen lamps now.Thanks for all the help fella's

Greg63 · 11-06-2007, 02:55 PM

Very iluminating

10-29-2007, 07:30 PM	#1
1966gmc Why does it taste purple? Join Date: Sep 2007 Location: Cambridge Md Posts: 621	Help!!! no low beams and dim high beams I never drive the truck at night but would like to every once and awhile.Anywhoo,I noticed a few weeks ago that my low beam light on the passenger side was dim and the driver side does not come on.If I turn on the high beams,the low beam on the drivers side will light up and is quite bright while the others are dim.I got fooling around with the passenger side tonight and now the low beams do not work until you turn on the high beams.All other lights work(tails,brake and turn signals) fine. What in the hell is goin on? A bad ground somewhere? Please help

10-29-2007, 08:38 PM	#3
Chevy Fleetside Registered User Join Date: Sep 2006 Location: San Francisco Posts: 4,782	Re: Help!!! no low beams and dim high beams Also.. Make sure the plug at the radiator support is clean. Unplug it and try to clean it. __________________ "A man and his truck, what a beautiful thing" 65 Short Fleetside BBC 65 Long Fleetside 283 3 on the tree for now. my build thread http://www.67-72chevytrucks.com/vboa...d.php?t=259536

10-30-2007, 02:07 PM	#4
Greg63 Enjoy your truck Join Date: Oct 2007 Location: Newmarket, Ontario, Canada Posts: 1,066	Re: Help!!! no low beams and dim high beams I had a similar problem to yours a few years back . My highs and lows were dim all the time . I did some research and found this solution ; I rewired the headlight circuit so that instead of the headlight switch sending power directly to the headlights , the headlight switch now sends power to a pair of relays . One relay is for high beams and the other relay is for low beams . The headlight switch powers the contactors in the relays (which draws less amperage than the headflights) and the higher amperage headlights are powered through the contacts . There is virtually no voltage loss to the headlights this way and there is less strain on the headlight switch . I now have much brighter headlights . __________________ 1 Corinthians 10:13 1963 Chevrolet 1/2 ton 2010 Camaro SS/RS 2014 Jeep Grand Cherokee 2016 Jeep Cherokee

11-01-2007, 01:31 PM	#5
jchav62 1962 C-10 Join Date: Apr 2005 Location: Las Vegas, New Mexico Posts: 4,978	Re: Help!!! no low beams and dim high beams Check the wires with a light tester and see if you're check juice there. How old are the bulbs? Maybe there just burnt out. __________________ Joseph Chavez "See the USA in a Chevrolet!!" ......................_____ .........________//__{\_____ ,,,,,,,/__(O)___//___/__(O)_/ 1962 C10 Shortbed Fleetside 327/th350 GV overdrive 1974 C10 Longbed Fleetside 350/th350 "The Trash Truck" 1999 Chevy 2500 OBS, Longbed 5.7/4L80E 4x4 2015 GMC Sierra SLE 1500 4x4

11-01-2007, 02:26 PM	#6
rodnok1 Registered User Join Date: Jun 2003 Location: Linden, North Carolina Posts: 617	Re: Help!!! no low beams and dim high beams Check the actual connections at the headlights, they get corrorded and loose over time. __________________ 64 Panel Rebuild Pics Clutch Replacement and Borg Warner T10 Trans Rebuild 64 Panel 1/2 Ton 350cubes/400hp BorgWarner t-10 3:73 Auburn Posi

11-01-2007, 03:06 PM	#7
Mesabooger Registered User Join Date: Apr 2007 Location: Colorado Posts: 9	Re: Help!!! no low beams and dim high beams I had the same problem, turned out to be there was not a good ground. The grill had been repainted and non of the grill was grounding.

11-01-2007, 05:20 PM	#8
Cobblemizer Registered User Join Date: Apr 2007 Location: Northern Illinois Posts: 64	Re: Help!!! no low beams and dim high beams I had the same problem on my 63 and the wires on the high/low beam switch where corroded (years of wet boot and shoes mixed with road salt do wonders to electrical parts!)

11-06-2007, 01:29 PM	#9
1966gmc Why does it taste purple? Join Date: Sep 2007 Location: Cambridge Md Posts: 621	Re: Help!!! no low beams and dim high beams Hey y'all.I finally got off my rear and found that the grounds were not in the best of shape.I did the headlight relay mod and ran a solid ground from all the lights to the neg battery terminal while I was in there.All lights are functional now yay! Now all I have to do is invest in some halogen lamps now.Thanks for all the help fella's

11-06-2007, 02:55 PM	#10
Greg63 Enjoy your truck Join Date: Oct 2007 Location: Newmarket, Ontario, Canada Posts: 1,066	Re: Help!!! no low beams and dim high beams Very iluminating __________________ 1 Corinthians 10:13 1963 Chevrolet 1/2 ton 2010 Camaro SS/RS 2014 Jeep Grand Cherokee 2016 Jeep Cherokee

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