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How many grounds on your car?

Brunoboy

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I started thinking about my power situation in y car. I run gauges , aftermarket headunit, rewire for the pump and alarm. Anywho I run one ground for the battery and maybe a engine ground to chasis. I do have a lot of power issues within the car and was wondering how manygrounds do you all have? What size is your battery and specs of it? And does anyone have power problems?
-shane
 

Struc

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There have been quite a few threads on grounding here. Yes, improper grounding will cause all sorts of issues.
 

Brunoboy

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Any idea on how many ground you have? And where they are and what gauge?
-shane
 

Struc

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I have my battery relocated to the trunk. I have 2 4ga grounds in the trunk, and one 4ga extended up to the center of the car near the shifter. I have the wire & connectors to extend it to the engine bay, which I'll be doing soon. From there, I'll be adding a couple extra in the engine compartment, specifically one to the alternator.
 

Brunoboy

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So all the grounds are off the battery terminal? And what gauge for the alternator?
 

Brunoboy

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Oh btw I have my battery in the trunk as well.
-shane
 

Tre3zy

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i got 1 in the trunk.... battery to shock tower.... and about 7 in the engine bay
 

jepherz

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Quoting brunoboy:
So all the grounds are off the battery terminal? And what gauge for the alternator?



What exactly are you asking here? All ground has to go back to the battery, eh?
 

Brunoboy

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Yes^ are all grounds have to go back to the Neg terminal? Or can it be engine to chassis and such?
 

jepherz

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It's not as simple as asking "how many" grounds. Yes, you can run a ground from the engine block to the chassis, but in the end, that current has to return to the battery through whichever grounds connect the chassis to the battery. Most people don't understand that the ground current is just as much as the (+) current. If you need to add a 2 guage wire to your starter, then you have to have just as much wire going back to the battery.
 

Brunoboy

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So for example, I have my battery in the trunk wired by a 4gauge wire . For grounds, I would run a 4gauge wire from the alt to the strut tower to the intake manifold to the exhaust manifold to the tranny , and the head. But somewhere along the path it has to go back to the battery?.
 

turbowop

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It goes back to the battery via the whole steel unibody that is the car. Anywhere you terminate a ground wire to the main unibody will have continuity with the main negative cable on the battery.
 

Brunoboy

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so if If i ground my battery in the trunk, and I were to ground the engine,trans, alt and all that to the chassis at the strut towers and firewall and such, that would be just as good, as routing back to the negative terminal in the trunk?
 

jepherz

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Quoting brunoboy:
So for example, I have my battery in the trunk wired by a 4gauge wire . For grounds, I would run a 4gauge wire from the alt to the strut tower to the intake manifold to the exhaust manifold to the tranny , and the head. But somewhere along the path it has to go back to the battery?.



I'm not sure why you'd need/want grounds on the intake, head, tranny, and exhaust manifold, can you give any reasoning for this? Maybe a good ground at one of those locations so that all of the sensors are covered and there is adequate ground from the ignition system, but grounding all of those locations is excessive and pointless.
 

Brunoboy

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i was on tuners and they had a thread explaining how many ground wires they had and where they put them, those were all what were listed as locations to ground.
 

turbowop

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There are already factory grounds to most of the locations you mention. As long as all the sensors see ground, you're good. I've measured the resistance to all ground points on my car from where my battery is grounded in the trunk to the front of the car at the firewall and engine and it is pretty much nothing. On both cars. People worry waaaaay too much about grounds. Perhaps you should bust out the multimeter and check your factory grounds before you start spending money on useless mods.
 

Brunoboy

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I only have the battery Neg and the trans to firewall...
 

alansupra94

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I thought you would be fine for a battery relocation as long as you make a clean ground into the uni-body?
 

curtis

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Think about it. If the whole car was one piece of steel it would be fine but its not. Most panels might have 10 to 20 sport welds. Resistivity of steel compared to a large copper wire is probably a magnitude of 50 times greater in favor of the copper. Run extra grounds and don't trust just connecting it to the trunk floor. Causes crazy intermittent problems down the road.
 

turbowop

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That sounds great in theory, Curtis... but in practice, one ground works fine. Unless you are dealing with some rusted out POS hoopty, or have other issues, the unibody works great as a conductor.

I've tested the resistance between my trunk ground location and every factory firewall ground location as well as a bunch of random spots all over the engine. No resistance. ON BOTH CARS. It works fine.
 
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