How to create a ground? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

RainDog · 03-11-2003, 02:32 PM

Hey guys---say I'm trying to eliminate some electrical Gremlins in my truck that seem to be hanging around the radio, turn signal, and tail lights, and I was pretty sure they're the result of a series of bad grounds--what's the easiest way to make a "new" ground for the circuit without tearing into my wiring? Can I just attach something metal that will conduct 12 volts no prob from the wire to the cab/frame/etc.? Or is it more complicated than that? Hope that question makes sense!

RainDog

*Gee_Emm* · 03-11-2003, 03:22 PM

Its easy, connect the negative battery cable to the frame and body with some good connections!

The "ground"on a vehicle is basically just like a wire except it is not covered by insulation and it flows through anything that is metal.

RainDog · 03-11-2003, 03:53 PM

So, if I have a grounding problem now somewhere, will creating a good ground fix that?

RainDog

*Gee_Emm* · 03-11-2003, 04:21 PM

Well, either creating a better one from the battery to the frame and body, or creating a better ground at the accesory. Try testing your ground before doing unneeded rewiring.

**COBALT** · 03-11-2003, 04:27 PM

Any 12v auto circuit works by a difference between full potential (12v) and zero potential (relative ground, or near-0v) with measurable resistance so current will flow. Auto circuits don't have true grounds - in other words they don't terminate to a ground source like you'd see with household wiring. Since there isn't a true ground there's generally only two wires for every circuit: a power and a neutral for relative ground. Your live circuits that provide 12v should be insulated from the cab, frame, engine, and sheetmetal, so any ground to any circuit in your truck is connected to these things to create the difference in potential between 12v and 0v.

To make a ground that you can rely on to have near-0v:

1. Find a reliable 12v circuit that doesn't have a short or bleeds current off to another source. Make sure that's powering your circuit.

2. Find bare metal on your cab, frame, engine, or sheetmetal of your fenders, bed, or wherever, and mount a steel, brass, or copper screw.

3. Tie your (-) side of your circuit to that screw, and your circuit should be properly grounded.

A fast way to test grounds is to get an automotive tester with a 12v bulb in the handle. It should have a wire hanging out with an alegator clip you can connect to a power source, and it should be pointed like an awl so you can touch various parts of your truck to see if the bulb lights up. If it does (and it lights up FULLY) you just found a ground.

Fred T · 03-11-2003, 04:33 PM

Here's my recommendation on grounding. Cable from battery to block. The rest uses 10 gauge wire. Battery to inner fender and inner fender to frame, using a common connection. Also wire from frame to bed. Sand all paint and rust from mating surfaces and assemble connections with di-electric grease. If you're having problems with the instrument panel, add a ground to that, too.

RainDog · 03-11-2003, 06:01 PM

Thanks for the replies guys! I'm still a little confused, but as soon as this rain quits I'm going to get to work. This beast is ALMOST ready to drive; When I bought her, she had no exhaust, no license plates, no windshield wipers, no turn signals, and a bad tail light--All I have left to fix is the turn signals and tail light! I'll keep you posted,

RainDog

tim m · 03-11-2003, 10:44 PM

When I do anything with grounding, I drill and tap the hole, usually use 1/4-20. Then you dont have to worry about removing the paint.

ZOOMY · 03-12-2003, 05:40 AM

Fre t hit it right on the money, except he forgot frame to cab unless he meant cab frame. You can't over ground, but you sure can under ground........Zoomy

03-11-2003, 02:32 PM	#1
RainDog Registered User Join Date: Mar 2001 Location: Burien, WA, USA Posts: 391	How to create a ground? Hey guys---say I'm trying to eliminate some electrical Gremlins in my truck that seem to be hanging around the radio, turn signal, and tail lights, and I was pretty sure they're the result of a series of bad grounds--what's the easiest way to make a "new" ground for the circuit without tearing into my wiring? Can I just attach something metal that will conduct 12 volts no prob from the wire to the cab/frame/etc.? Or is it more complicated than that? Hope that question makes sense! RainDog __________________ "Every normal man must be tempted at times to spit on his hands, hoist the black flag, and begin slitting throats."

03-11-2003, 03:53 PM	#3
RainDog Registered User Join Date: Mar 2001 Location: Burien, WA, USA Posts: 391	So, if I have a grounding problem now somewhere, will creating a good ground fix that? RainDog __________________ "Every normal man must be tempted at times to spit on his hands, hoist the black flag, and begin slitting throats."

03-11-2003, 04:27 PM	#5
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Any 12v auto circuit works by a difference between full potential (12v) and zero potential (relative ground, or near-0v) with measurable resistance so current will flow. Auto circuits don't have true grounds - in other words they don't terminate to a ground source like you'd see with household wiring. Since there isn't a true ground there's generally only two wires for every circuit: a power and a neutral for relative ground. Your live circuits that provide 12v should be insulated from the cab, frame, engine, and sheetmetal, so any ground to any circuit in your truck is connected to these things to create the difference in potential between 12v and 0v. To make a ground that you can rely on to have near-0v: 1. Find a reliable 12v circuit that doesn't have a short or bleeds current off to another source. Make sure that's powering your circuit. 2. Find bare metal on your cab, frame, engine, or sheetmetal of your fenders, bed, or wherever, and mount a steel, brass, or copper screw. 3. Tie your (-) side of your circuit to that screw, and your circuit should be properly grounded. A fast way to test grounds is to get an automotive tester with a 12v bulb in the handle. It should have a wire hanging out with an alegator clip you can connect to a power source, and it should be pointed like an awl so you can touch various parts of your truck to see if the bulb lights up. If it does (and it lights up FULLY) you just found a ground. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

03-11-2003, 04:33 PM	#6
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	Here's my recommendation on grounding. Cable from battery to block. The rest uses 10 gauge wire. Battery to inner fender and inner fender to frame, using a common connection. Also wire from frame to bed. Sand all paint and rust from mating surfaces and assemble connections with di-electric grease. If you're having problems with the instrument panel, add a ground to that, too. __________________ Fred There is no such thing as too much cam...just not enough engine.

03-11-2003, 06:01 PM	#7
RainDog Registered User Join Date: Mar 2001 Location: Burien, WA, USA Posts: 391	Thanks for the replies guys! I'm still a little confused, but as soon as this rain quits I'm going to get to work. This beast is ALMOST ready to drive; When I bought her, she had no exhaust, no license plates, no windshield wipers, no turn signals, and a bad tail light--All I have left to fix is the turn signals and tail light! I'll keep you posted, RainDog __________________ "Every normal man must be tempted at times to spit on his hands, hoist the black flag, and begin slitting throats."

03-11-2003, 03:22 PM	#2
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 4,002	Its easy, connect the negative battery cable to the frame and body with some good connections! The "ground"on a vehicle is basically just like a wire except it is not covered by insulation and it flows through anything that is metal.

03-11-2003, 04:21 PM	#4
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 4,002	Well, either creating a better one from the battery to the frame and body, or creating a better ground at the accesory. Try testing your ground before doing unneeded rewiring.

03-11-2003, 10:44 PM	#8
tim m Registered User Join Date: Mar 2001 Location: Gilbert Az Posts: 286	When I do anything with grounding, I drill and tap the hole, usually use 1/4-20. Then you dont have to worry about removing the paint. __________________ 1970 k10 1971 C10 Gilbert Az

03-12-2003, 05:40 AM	#9
ZOOMY Senior Member Join Date: Feb 2003 Location: WIS Posts: 1,752	ground Fre t hit it right on the money, except he forgot frame to cab unless he meant cab frame. You can't over ground, but you sure can under ground........Zoomy



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