STupid.....LighTS!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

WRMZ71 · 11-25-2003, 11:24 PM

Does anybody know if there is a main ground for the turn signals and dash lights inside the cab on a 71 chevy halft ton? when i turn on my left turn signals they work fine, when i turn on my 4 ways they work fine, but when i turn on the right side both lights in back blink the front left side marker light blinks and all the dash lights blink

I've replaced the turn signal switch, the light switch and pulled off the rear wiring harness and there aren't any faults. I've figured out that the rear left turn signal is blinking through the brown wire which is lights???? Any ideas ???? HELP!!!

dinnut · 11-25-2003, 11:26 PM

my ground is on a screw at the bottom of the gauges to the right of the steering column

ozarkhippie · 11-25-2003, 11:27 PM

Did you have this problem before you changed the turn sig. switch?

jmanz69 · 11-25-2003, 11:33 PM

Check the frame grounds too. I had a similar problem and found it was the rear tail light frame ground. The rear lights ground to the bracket which grounds to the box which grounds to the frame which should ground to your neg battery terminal. Make sure it is all connected. It will drive you nuts trying the chase down a ground problem if you don't make sure all grounds are tight and good. Good Luck

WRMZ71 · 11-27-2003, 09:43 PM

Yes i still had the problem before i changed the turnsignal switch. I had found another problem with the lights that when you turned on the headlights the right turn signal would flash. The new turn signal switch took care of that but not my other problems. I'm pretty sure it's gotta be some type of ground in the cab because at the harness in the firewall where it goes to the back I get the blinking volts at the dark green wire which is ps rear turnsignal but also the brown which is the headlights circuit. I traced the brown wire back and it plugs into the headlight switch . i unplugged that there and they still blink. I then checked for continuity between the dark green and brown wires to see if they were cut and touching somewhere but i didn't get any continuity

I'm running out of ideas. Does anybody know if the fuseblock grounds itself out when you bolt it into the firewall? I took it off and looks all plastic. I found one black wire running out of the back of the fuse panel and it ran up to the radiator support above the old voltage regulator. I cleaned it all up and still nothing. Any body got any more ideas? Any help would be greatly appreciated. Thanks

ozarkhippie · 11-27-2003, 10:03 PM

I just looked on my 72 there is a ground up by the voltage reg. also. Not saying this will find your prob. but unplug the rear lights at the plug in the back and then see if you still have the prob.

WRMZ71 · 11-27-2003, 10:27 PM

the front lights flash too and so do the dash lights.I was just out playing with it cleaning up my grounds in back and threw the multimeter on it and it gets power like that. What i'm looking at now is 2 small boxes on the ds firewall right by where the wiring mount is on the back of the fuse box. theres one brown wire that runs itnto 2 what appear to be black ones. when i unplug the clip the front 2 light markers go off. Could all of the lights be run through these 2 mysterious boxes and what the hell are they? I look in my haynes manual and there not covered.

11-25-2003, 11:24 PM	#1
WRMZ71 Cause the Chicks DIG IT!! Join Date: Nov 2003 Location: Beaufort SC Posts: 509	STupid.....LighTS!!! Does anybody know if there is a main ground for the turn signals and dash lights inside the cab on a 71 chevy halft ton? when i turn on my left turn signals they work fine, when i turn on my 4 ways they work fine, but when i turn on the right side both lights in back blink the front left side marker light blinks and all the dash lights blink I've replaced the turn signal switch, the light switch and pulled off the rear wiring harness and there aren't any faults. I've figured out that the rear left turn signal is blinking through the brown wire which is lights???? Any ideas ???? HELP!!!

11-25-2003, 11:26 PM	#2
dinnut Registered User Join Date: Apr 2003 Location: missouri city, tx Posts: 4,486	my ground is on a screw at the bottom of the gauges to the right of the steering column __________________ 70 longbed 496/th400/Ford 9"

11-25-2003, 11:27 PM	#3
ozarkhippie Registered User Join Date: Nov 2002 Location: Eureka Springs AR Posts: 494	Did you have this problem before you changed the turn sig. switch? __________________ Buy Sale or Trade 71 3/4 4x4 72 1/2 ton cheyenne 4x4

11-27-2003, 10:03 PM	#6
ozarkhippie Registered User Join Date: Nov 2002 Location: Eureka Springs AR Posts: 494	I just looked on my 72 there is a ground up by the voltage reg. also. Not saying this will find your prob. but unplug the rear lights at the plug in the back and then see if you still have the prob. __________________ Buy Sale or Trade 71 3/4 4x4 72 1/2 ton cheyenne 4x4

11-25-2003, 11:33 PM	#4
jmanz69 Careful, they attack... Join Date: Aug 2001 Location: Waterford, MI, USA Posts: 1,107	Check the frame grounds too. I had a similar problem and found it was the rear tail light frame ground. The rear lights ground to the bracket which grounds to the box which grounds to the frame which should ground to your neg battery terminal. Make sure it is all connected. It will drive you nuts trying the chase down a ground problem if you don't make sure all grounds are tight and good. Good Luck

11-27-2003, 09:43 PM	#5
WRMZ71 Cause the Chicks DIG IT!! Join Date: Nov 2003 Location: Beaufort SC Posts: 509	Yes i still had the problem before i changed the turnsignal switch. I had found another problem with the lights that when you turned on the headlights the right turn signal would flash. The new turn signal switch took care of that but not my other problems. I'm pretty sure it's gotta be some type of ground in the cab because at the harness in the firewall where it goes to the back I get the blinking volts at the dark green wire which is ps rear turnsignal but also the brown which is the headlights circuit. I traced the brown wire back and it plugs into the headlight switch . i unplugged that there and they still blink. I then checked for continuity between the dark green and brown wires to see if they were cut and touching somewhere but i didn't get any continuity I'm running out of ideas. Does anybody know if the fuseblock grounds itself out when you bolt it into the firewall? I took it off and looks all plastic. I found one black wire running out of the back of the fuse panel and it ran up to the radiator support above the old voltage regulator. I cleaned it all up and still nothing. Any body got any more ideas? Any help would be greatly appreciated. Thanks

11-27-2003, 10:27 PM	#7
WRMZ71 Cause the Chicks DIG IT!! Join Date: Nov 2003 Location: Beaufort SC Posts: 509	the front lights flash too and so do the dash lights.I was just out playing with it cleaning up my grounds in back and threw the multimeter on it and it gets power like that. What i'm looking at now is 2 small boxes on the ds firewall right by where the wiring mount is on the back of the fuse box. theres one brown wire that runs itnto 2 what appear to be black ones. when i unplug the clip the front 2 light markers go off. Could all of the lights be run through these 2 mysterious boxes and what the hell are they? I look in my haynes manual and there not covered.



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