Grounding How to

**owenjh** · 12-29-2003, 12:36 AM

ok, just got to make my case now before its all ready to be put into the car. I have a question. What is the best way to ground it?
I was thinking using those metal standoff's with some kind of wiring connected to each one to ground them, and running that to the ground of the power supply. then running the ground of the power supply to the frame of the car. I am using an inverter and I have heard that I cannot connect the computer stuff to the ground of the inverter, is this true? the power supply ground is not anyway connected to the power supply, on a regular computer it would just be grounded to the case. Any suggestions?

**hijinks21** · 12-29-2003, 08:07 AM

forget what you heard cause its all BS.

Get your power for the inverter from the battery and ground the inverter to the car frame. Then make sound wire and ground your PSU to the same spot as your inverter. You shouldn't need to ground your mobo.. but if you still get some noise then ground that to the same spot also. The problem if you ground to two many different spots is you create a ground loop which is a bad thing

**MikeH** · 12-29-2003, 11:25 AM

I had a TON of audio noise from my inverster (before I got rid of it). I found that if I used a 2-prong AC adapter plug in the 3-prong AC outlet of the inverter, and didn't connect the adapter ground to anything, it got rid of most of the audio noise. BUT, all situations are different since not 2 inverters are alike. You may try this if you end up with lots of noise.

**psyclobe** · 12-29-2003, 03:56 PM

Originally Posted by hijinks21

forget what you heard cause its all BS.

Get your power for the inverter from the battery and ground the inverter to the car frame. Then make sound wire and ground your PSU to the same spot as your inverter. You shouldn't need to ground your mobo.. but if you still get some noise then ground that to the same spot also. The problem if you ground to two many different spots is you create a ground loop which is a bad thing

I read in some car stereo book that when grounding multiple components, you should not ground them to the same spot, nor should you ground them in spots very far from each other. Instead you should ground them in the same close vicinity.

-Jason

**meddler** · 12-29-2003, 07:45 PM

My theory is put your grounds as close as possible to each other. If you have noise problems then take further action and try a single point ground. You will find that most of the inverters are very noisy anyway, so it may not matter what you do, you may never be able to get rid of the noise.
I had an amp once that when screwed down to the car body was noisy. I mounted it on a piece of MDF and the noise pretty much went away. There ended up being an earth loop within the amp itself between the -ve lead and the case of the amp. That's what you get for buying a crap quality amp.

**starfox** · 12-30-2003, 08:30 AM

If you're grounding to the car chassis, make sure that the cable from the chassis to the negative terminal of the battery is sufficient for all of the stuff you've put into your car.

Having lots of 4 AWG cable running off your positive battery terminal, and having a single 8 AWG cable running from your car chassis back to your negative terminal doesn't make sense

, but it's something people overlook...

**owenjh** · 12-30-2003, 10:51 AM

Thanks for all the info.
I was going to have a + / - wire running from the battery to the inverter. Then i was going to ground the motherboard out, and the ground of the power supply unit (normally connected to computer case) to the chassis. Will this be sufficient? Also what kind of wire should I buy, and how do I ground to the chassis?