Troublesome Lights - The 1947 - Present Chevrolet & GMC Truck Message Board Network

crawdad · 10-19-2007, 06:58 PM

The headlights on my 85 are not working properly. When I turn them on bright, the dims come on. When I turn them on dim they all go out.

The PO had unplugged the upper headlights under the hood, and now I know why. What could cause this. I do know that I've got to replace the blinker/dimmer switch on the steering column. It was real stiff and I wound up breaking the stem off when I brought the truck home. Would the blinker/dimmer switch cause this problem? Any suggestions on what to check would be appreciated. Thanks.

chev74 · 10-19-2007, 07:56 PM

how much did you pay for this truck... just kidding! lets help this man!

BLE 'BURBAN · 10-19-2007, 08:14 PM

I take it this is a 4 light system stacked on top of one another low beams being on top and high beams being on the bottom. The low beam headlights have both high & low beam elements in them while the high beams are a single element lamp. It could be that low beam element in both lamps are fried. But with what you said about the dimmer switch, that might be the cause as well if it's not allowing the low beam circuit to close.

DBLSPRT68 · 10-19-2007, 08:17 PM

[QUOTE I do know that I've got to replace the blinker/dimmer switch on the steering column. Would the blinker/dimmer switch cause this problem? [/QUOTE]

I'm 99% sure this will fox it. I had the high beam switch on the floor, and when it went out; low beams fine, high beam no headlights at all. Check the connections at the lights, and replace the switch. Report back to let us know. David

**old Rusty C10** · 10-19-2007, 08:34 PM

you can test the lights with a test light if you have power to the tabs that plug onto the lights you know its the bulbs if no power and the ground is good then check the switch is prolly bad

jermasaurus · 10-20-2007, 08:16 AM

Not to hijack the thread, or change the subject completely- But when the 4 light system is working correctly, should all 4 lights be on when when switched to brights?

**old Rusty C10** · 10-20-2007, 09:29 AM

yes

10-19-2007, 06:58 PM	#1
crawdad Senior Member Join Date: Sep 2004 Location: Georgia Posts: 614	Troublesome Lights The headlights on my 85 are not working properly. When I turn them on bright, the dims come on. When I turn them on dim they all go out. The PO had unplugged the upper headlights under the hood, and now I know why. What could cause this. I do know that I've got to replace the blinker/dimmer switch on the steering column. It was real stiff and I wound up breaking the stem off when I brought the truck home. Would the blinker/dimmer switch cause this problem? Any suggestions on what to check would be appreciated. Thanks. __________________ 2012 Silverado LT 1500, 5.3, 6 speed auto '86 SWB C-10 Silverado

10-19-2007, 07:56 PM	#2
chev74 Addicted to Chevy Join Date: Dec 2004 Location: Tyler, Tx Posts: 857	Re: Troublesome Lights how much did you pay for this truck... just kidding! lets help this man!

10-19-2007, 08:14 PM	#3
BLE 'BURBAN In the Forgotten far North. Join Date: Jul 2007 Location: Anchorage, Alaska Posts: 2,627	Re: Troublesome Lights I take it this is a 4 light system stacked on top of one another low beams being on top and high beams being on the bottom. The low beam headlights have both high & low beam elements in them while the high beams are a single element lamp. It could be that low beam element in both lamps are fried. But with what you said about the dimmer switch, that might be the cause as well if it's not allowing the low beam circuit to close. __________________ 1987 R3500 CREW CAB DUALLY (BIG RED)Acquired 06/12/2015 1990 chevy suburban V2500 5.7L My cluster Mods-Nov 2007 overhead console Stereo install Round 2 Aug 2009 Heated/turn signal mirror upgrade Last edited by BLE 'BURBAN; 10-19-2007 at 08:40 PM.

10-19-2007, 08:17 PM	#4
DBLSPRT68 Registered User Join Date: Nov 2000 Location: Ft. Mill, SC USA Posts: 931	Re: Troublesome Lights [QUOTE I do know that I've got to replace the blinker/dimmer switch on the steering column. Would the blinker/dimmer switch cause this problem? [/QUOTE] I'm 99% sure this will fox it. I had the high beam switch on the floor, and when it went out; low beams fine, high beam no headlights at all. Check the connections at the lights, and replace the switch. Report back to let us know. David __________________ PROJECT TRUCK: 1985 SWB C10 Silverado Black/Charcoal, 1990 V2500 Suburban, 2018 Suburban, 2005 GMC 2500HD CCSB, 2014 Toyota Camry SE, HAD.....1968 Camaro RS/SS Family owned since new; 350 3 speed SOLD

10-19-2007, 08:34 PM	#5
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,300	Re: Troublesome Lights you can test the lights with a test light if you have power to the tabs that plug onto the lights you know its the bulbs if no power and the ground is good then check the switch is prolly bad __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

10-20-2007, 08:16 AM	#6
jermasaurus Registered User Join Date: Dec 2004 Location: New Lenox, IL Posts: 442	Re: Troublesome Lights Not to hijack the thread, or change the subject completely- But when the 4 light system is working correctly, should all 4 lights be on when when switched to brights? __________________ 79 Jimmy slammed AKA James Down

10-20-2007, 09:29 AM	#7
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,300	Re: Troublesome Lights yes __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!



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