Ground Wire

[AcidicDreams 10+ year member]

I was thinking....
I could mount two 0/1 grounds to the frame, connect two 0/1 grounds from the battery to the same frame rail and accomplish the same thing for cheaper?

I drive a truck so it's a real frame.

Well that is the point of the big 3.... I dunno about an actual frame, it's a little diff than a unibody

 

[ultimate157 5,000+ posts]

Check continuity by taking a DMM from the - battery terminal to your test spot. Make sure to put the DMM to resistance, or Ohms.

 

[Flipx99 5,000+ posts]

Check continuity by taking a DMM from the - battery terminal to your test spot. Make sure to put the DMM to resistance, or Ohms.

That's quite a long way...

I assume the lower the reistance the better and I could do no better than the value of battery + to battery - ?

 

[ultimate157 5,000+ posts]

theoretically, the lowest you can achieve is 0 ohms.

 

[Flipx99 5,000+ posts]

Get what I am saying though....the battery to a ground in the back of the truck is longer than my DMM prongs.

Can I use the amp wire as a proxy? I know I will see some resistance just from the battery, but that would be there in an actual application.

I am correct in the less resistance the better when it comes to ground?

 

[AcidicDreams 10+ year member]

Get what I am saying though....the battery to a ground in the back of the truck is longer than my DMM prongs.
Can I use the amp wire as a proxy? I know I will see some resistance just from the battery, but that would be there in an actual application.

I am correct in the less resistance the better when it comes to ground?

Less resistance is better for the main power wire too...

 

[XanderMoser 10+ year member]

If your DMM terminals are not long enough, just use a wire. First check the resistance of the wire and the DMM terminals. Then measure the resistance of the ground spot to the battery - . Now subtract the amount you measured that the terminals and wire have. This resulting value is the resistance from your grounding spot to the battery - .

 

[Radioflyer97 10+ year member]

in most cars, the seat mounting bolts make excellent grounds. they usually go streight into the frame.

If you're running the traditional stock battery location, grounding to the frame is fine. If you're running additional batteries, you may want to run a seperate ground wire.

 

[NewToTheGrounds 10+ year member]

sorry to jack, but is it fine to be running a ground from ur bat the stock one plus running a ground from ur amp to the body by the amp? (my amp is in the trunk can i also run a secondary grnd wire from my amp to the frame in the back?) or can this cause grounding loops.

 

[helotaxi 5,000+ posts]

Ground loops in the generally referred to car audio sense are differences in the ground path resistance between two components in the signal chain that use ground as a signal reference. The component with the higher resistance on its power ground will then partially ground through the signal cable and the result is ripple voltage form the alt finding its way into the audio signal.

If you are grounding to the battery anyway, there is absolutely no point in adding another ground for the amp to the chassis. The battery is reference ground anyway. The chassis is grounded to the battery, not the other way around.

As far as testing the resistance of a grounding point, if you can measure the resistance with a normal DMM, it's too high. 20ft (which is a really long ground in a car) of 4ga copper wire has a resistance of 0.005 ohms. That is the max resistance you'd be looking for if you were running a system that needed 4ga power wire. That is much smaller than the min reading on a normal DMM.