Basic Electrical question...

[Mike86Stang]

I have a circut if grounded though the chassis reads 12v(battery volts).
If I ground the same wire through the harness it reads .20v

Is this a case of a bad ground?

Thanks
Mike

 

[srothfuss]

If you are unable to pass electricity throught the harness, then the circuit is not completed somewhere along the line.

The entire car is grounded to the chassis (obviously.) So when you lose voltage at the harness, you are lacking a ground or there is a short.

 

[jrichker]

I'd like to help, but I just can't visualize what is hapenning. Draw a picture maybe?

 

[Mike86Stang]

would this still apply on a dimmer circut?

 

[Mike86Stang]

jr- basically i'm checking the voltage at the cluster for the dash lights.

If I probe the power wire & ground it through the harness as would be "normal" I get .20 volts. If I move my ground lead off the harness & to the chassis (bare steel) I get 12.v

I think it's a bad ground

 

[Mike86Stang]

bump

 

[HISSIN50]

I agree Mike - that sounds like a bad ground to me - But I'm no Jrichker.

Did you check continuity of said-wire to ground with your meter?

Good luck.

 

[srothfuss]

Do we know the dimmer switch is good? Those things can get flat spots in them over time. I think I would start there and move backwards to find the source.

 

[jrichker]

jr- basically i'm checking the voltage at the cluster for the dash lights.

If I probe the power wire & ground it through the harness as would be "normal" I get .20 volts. If I move my ground lead off the harness & to the chassis (bare steel) I get 12.v

I think it's a bad ground

Now that I have my electrical hat on, plugged in and powered up, I can try to answer your question...

With the power off, measure the resistance between the ground wire for the circuit & the chassis. You should have less than 2 Ohms. More than that & I would start lookiing for bad connections & broken wiring.

 

[SleeperStang]

Yeah what he said ^^

Empty your PMs punk

 

[jwdomino]

or to eliminate the "bad ground" idea. simply attach a ground at the harness to the wire that is supposed to be ground. check your lighting. if it works trace the ground wire through the harness and repair at break. If it does nothing and you still have the problem check your switch.