Car Audio Technical Discussions Dedicated to the technical side of Car Audio.

How to test ground with a DMM

Thread Tools
 
Search this Thread
 
Old 01-13-2008, 06:07 PM
  #1  
0 Watt CAFz'r
Thread Starter
 
Mr Burns's Avatar
 
Join Date: Oct 2007
Posts: 32
How to test ground with a DMM

Could one of you knowledgable people please explain to me the process of testing for a good ground, using a digital multi meter? Where to make connections etc.
Mr Burns is offline  
Old 01-13-2008, 09:31 PM
  #2  
500 Watt CAFz'r
iTrader: (16)
 
splescort's Avatar
 
Join Date: Feb 2006
Posts: 612
put the meter on ohms and put the red test lead on the neg of the battery and the black test lead on the ground that you are trying to test. you want a reading less then 0.4 ohms
splescort is offline  
Old 01-15-2008, 05:42 PM
  #3  
50 Watt CAFz'r
 
SheHateMe's Avatar
 
Join Date: Jan 2007
Posts: 221
Kind of a dumb question, but would this be also ideal way to test to see if you have your system setup correct while it's all going on your intended listening levels? So in other words, should I do it while the systems on?
SheHateMe is offline  
Old 01-17-2008, 11:58 PM
  #4  
500 Watt CAFz'r
iTrader: (3)
 
zoomer's Avatar
 
Join Date: Mar 2006
Posts: 598
simply using a dmm to measure resistance may not do it. DMMS use very low currents to measure ohms. However you may have a bad connection that will pass low currents with minimal voltage drop, but as soon as you pass 10-20 or more amps the voltage drops. I have seen this several time.

So the best way is yes, first test with a DMM, but then you ahve to make sure the connections are SOLID! Then run your system loud and measure the voltage between a good chassis ground and the ground terminal of you amp. It should read almost Zero.
zoomer is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
provost5491
Install related
4
04-15-2014 09:21 AM
Tony@Amer Bass
Install related
20
03-05-2008 02:13 PM
Halo1
Install related
15
10-09-2004 08:59 AM
Xiph0id
General Discussion
28
02-12-2004 07:32 AM
ShYYLO
General Discussion
8
08-09-2003 06:12 PM



Quick Reply: How to test ground with a DMM



All times are GMT -5. The time now is 10:36 AM.