eclectrical ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

turmoline · 06-10-2003, 10:37 PM

Got an electrical ? for you guys. Brake lights work fine along with the rear turn signals with the headlights off. As soon as I turn the headlights on boom no brake lights and when I turn on a signal say the left one, it goes on but does not blink.

71GMC_3/4T · 06-11-2003, 12:36 AM

Check your ground wires from your bed to your frame. They should be up under the bed, just ahead of the rear tires. If they are there, check the turn signal housings, they should be grounded by the mounting hardware.

turmoline · 06-11-2003, 09:59 PM

I was thinking ground. I just have some makeshift lights on the frame (no bed installed) They are trailer lights. Am going to put the bed on soon. I'll check the ground install then. Thanks for the heads up. Mark

adkphoto · 06-12-2003, 12:20 PM

I have something almost exactly the same going on. Checked all the wires and they look fine. Replaced brake light switch and blinkers.... still no good.

Tore apart the sterring column to check the condition of the signal light switch....the amount of grease and dirt in there would be enough to kill any piece of electrical equipment. Fiddling with the switch would make certain lights work intermittently.

Needless to say, I ordered a new signal light switch and cleaned up the inside of the column. (haven't installed it yet so I don't know if that solves all of my problems)

New part is $40 from GMC Paul's

David

turmoline · 06-12-2003, 11:39 PM

adkphoto. yah I haven't been able to spend a whole lot of time fooling with it yet. My column is brand new and all the wiring to the backs are new as well. I'll probably start with the ground and go from there. keep me posted on how you make out. CAn't rule anything out at this point.

Jwill41 · 06-13-2003, 07:09 AM

dimmer switch can cause similiar problems. I have had to replace on both my trucks.

bouncytruck · 06-13-2003, 11:51 AM

I've seen a bad bulb do similar problems, but it was in a much newer car.

1967K10 · 06-13-2003, 01:00 PM

I also had a similar problem that ended up being a bad ground to the dash. I ran a ground wire directly (which fixed it) to it after much frustration and failed attempts to find the problem. My dad is a whiz with electrical, he used a multi-meter and the dimmer switch for the dash to determine it was a ground problem.

turmoline · 06-13-2003, 07:22 PM

how did you end up running the dash ground. I looked under the dash and saw that it was grounded but couldn't tell where it went as it went into the harness. Thanks

1967K10 · 06-13-2003, 09:16 PM

I ended up running it to the back top of the dash near the radio. There was a small bolt and a nut there to which I connected.

If you want I will call my dad and ask him how he trouble shot the ground with his multi-meter. Send me a PM or e-mail me.

turmoline · 06-14-2003, 12:42 AM

I've got some clip grounds that I can use to try to troubleshoot. I'll fool with that and get back with you. Thanks.

06-10-2003, 10:37 PM	#1
turmoline Registered User Join Date: Jul 2001 Location: santa cruz, Calif. U.S. Posts: 166	eclectrical ? Got an electrical ? for you guys. Brake lights work fine along with the rear turn signals with the headlights off. As soon as I turn the headlights on boom no brake lights and when I turn on a signal say the left one, it goes on but does not blink.

06-11-2003, 12:36 AM	#2
71GMC_3/4T Weapons Of Construction Join Date: Apr 2000 Location: Colorado, USA Posts: 1,095	Check your ground wires from your bed to your frame. They should be up under the bed, just ahead of the rear tires. If they are there, check the turn signal housings, they should be grounded by the mounting hardware. __________________ 1971 GMC 2500, 402/TH400 4.10 Daily Driver Lafayette, CO

06-12-2003, 12:20 PM	#4
adkphoto Registered User Join Date: Apr 2000 Location: Camillus, NY USA Posts: 79	I have something almost exactly the same going on. Checked all the wires and they look fine. Replaced brake light switch and blinkers.... still no good. Tore apart the sterring column to check the condition of the signal light switch....the amount of grease and dirt in there would be enough to kill any piece of electrical equipment. Fiddling with the switch would make certain lights work intermittently. Needless to say, I ordered a new signal light switch and cleaned up the inside of the column. (haven't installed it yet so I don't know if that solves all of my problems) New part is $40 from GMC Paul's David __________________ 1972 Chevy Cheyenne Super LWB Chevy Red/White with rally wheels. Not-so-Stock 350, A/T, A/C, tilt. Vroom, Vroom.... ===================== David Colbert dcolbert@twcny.rr.com Work hard, play harder!

06-13-2003, 07:09 AM	#6
Jwill41 Registered User Join Date: Aug 2002 Location: Farmers Branch, Tx Posts: 1,009	dimmer switch can cause similiar problems. I have had to replace on both my trucks. __________________ http://www.picturetrail.com/jwill41 67 1/2 ton GMC short step side 68 1/2 ton Chevy long fleet side 72 1/2 ton Chevy Suburban 99 1/2 ton Chevy Suburban founder (and only member) of the primer/clearcoat club

06-13-2003, 11:51 AM	#7
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,038	I've seen a bad bulb do similar problems, but it was in a much newer car. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

06-11-2003, 09:59 PM	#3
turmoline Registered User Join Date: Jul 2001 Location: santa cruz, Calif. U.S. Posts: 166	I was thinking ground. I just have some makeshift lights on the frame (no bed installed) They are trailer lights. Am going to put the bed on soon. I'll check the ground install then. Thanks for the heads up. Mark

06-12-2003, 11:39 PM	#5
turmoline Registered User Join Date: Jul 2001 Location: santa cruz, Calif. U.S. Posts: 166	adkphoto. yah I haven't been able to spend a whole lot of time fooling with it yet. My column is brand new and all the wiring to the backs are new as well. I'll probably start with the ground and go from there. keep me posted on how you make out. CAn't rule anything out at this point.

06-13-2003, 01:00 PM	#8
1967K10 Registered User Join Date: Jan 2003 Posts: 32	I also had a similar problem that ended up being a bad ground to the dash. I ran a ground wire directly (which fixed it) to it after much frustration and failed attempts to find the problem. My dad is a whiz with electrical, he used a multi-meter and the dimmer switch for the dash to determine it was a ground problem.

06-13-2003, 07:22 PM	#9
turmoline Registered User Join Date: Jul 2001 Location: santa cruz, Calif. U.S. Posts: 166	how did you end up running the dash ground. I looked under the dash and saw that it was grounded but couldn't tell where it went as it went into the harness. Thanks

06-13-2003, 09:16 PM	#10
1967K10 Registered User Join Date: Jan 2003 Posts: 32	I ended up running it to the back top of the dash near the radio. There was a small bolt and a nut there to which I connected. If you want I will call my dad and ask him how he trouble shot the ground with his multi-meter. Send me a PM or e-mail me.

06-14-2003, 12:42 AM	#11
turmoline Registered User Join Date: Jul 2001 Location: santa cruz, Calif. U.S. Posts: 166	I've got some clip grounds that I can use to try to troubleshoot. I'll fool with that and get back with you. Thanks.

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