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DISCUSSION => Electrical => Topic started by: pakman84 on April 13, 2010, 08:05:56 AM

Title: Tachometer, OBC,interior lights,etc.. not working
Post by: pakman84 on April 13, 2010, 08:05:56 AM

My MPG gauge,Tachometer,interior lights,trunk light and license plate lights are not working. I keep blowing fuse #21...So I tested each circuit with a battery powered voltage light tester and found that all of these circuits are lighting up my tester(going to ground). I then pulled up my driver side weatherstripping , moved the carpet and found splice # S319 and it lit up tester as well...Where do I go from here???
-John

Title: Tachometer, OBC,interior lights,etc.. not working
Post by: DesktopDave on April 13, 2010, 06:40:32 PM

Good question.  That harness heads back to the trunk, doesn't it?  Not that it'd matter if all parts of the circuit are shorted.  Maybe you have a short in the harness coming through the firewall?

Title: Tachometer, OBC,interior lights,etc.. not working
Post by: pakman84 on April 14, 2010, 07:35:56 AM

I agree...I think it is shorting where it comes through the firewall....Do I have to rip out my carpet to find it???

Title: Tachometer, OBC,interior lights,etc.. not working
Post by: DesktopDave on April 14, 2010, 10:18:07 AM

I think you could peel it back a little, but the pedals and that large foam pad in the footrest will be some trouble...it doesn't have to come out too far.  Any chafed wires should be easy to see if you don't mind being upside down in the foot well for a while.

In my e30, if I was totally sure that there was a short in the firewall harness I'd pull the entire dash to fix it right.  I'll bet I could have the dash out in an hour or two.  Be careful not to bend it too far or it'll crack above the dash cluster.

Title: Tachometer, OBC,interior lights,etc.. not working
Post by: pakman84 on April 14, 2010, 11:22:33 AM

I was going to replace the dash anyway so I'll check on it the...So does the harness go through the firewall into the dash and then down to the floor?

Title: Tachometer, OBC,interior lights,etc.. not working
Post by: DesktopDave on April 14, 2010, 11:42:36 AM

The harness comes in pretty high up to a pair of large connectors...it's more up in the dash area than the floor area.  If you look at the fusebox under the hood, it's all right below that.  Drop the lower kick panel under the dash & it'll all make more sense.

Title: Tachometer, OBC,interior lights,etc.. not working
Post by: pakman84 on April 14, 2010, 12:28:11 PM

That's wierd...I looked at the wiring schematic and it shows that red/green power from the fuse goes directly to splice #319 and not to a connector...

Title: Tachometer, OBC,interior lights,etc.. not working
Post by: pakman84 on May 08, 2010, 10:56:16 AM

Ended up cutting all of the wires going to the splice and checking each one and found my short....then resoldered all of them together...