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Discussion Starter #1
I just took apart my dash to move my stereo to the lower DIN slot and my aux. guages to the upper one. I put it all back together and everything worked fine. Then I was trying to figure out a good power source for the guages by tapping into one of the dash bulb sockets (the one for the red part of the heater control knob). This blew the fuse.

My problem now, is that I can't get the dash lights to come on without blowing a fuse (it's all back to stock, no guages interfering). I can turn the instrument cluster lights on, but as soon as I click on the dash light rheostat, the fuse blows and the instrument lights go out too. Make any sense?
I didn't make any permanent changes, and it's all back to normal now, I guess tomorrow I'll pull it apart to look at the rheostat, as I know that's finnicky. Any other suggestions? Thanks.
 

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Tyler:

You don't state the model year of your car -- in this case it makes a difference, particularly if it is pre-87 or 87 and later. In either case, a single fuse protects the entire dash lighting system, so if it blows, everything is dark.

The rheostat is unlikely to be your issue. If the fuse blows immediately, that means that there is a short. Since you've been changing the wiring, I would bet that something related to that has changed, not the rheostat. Besides, the rheostat is always upstream of the component that it controls so it is unlikely to create a direct-to-ground connection by itself.

I would re-inspect the wiring. Even if your wiring is perfectly routed, sometimes old insulation can crack or connectors will touch when you move wiring around.

Get an ohmmeter and measure the impedance across each component lead and ground. When you find the one where the reading is close to zero, you've found your problem.

Aren't electrical problems fun?
 

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Discussion Starter #3
Sorry for the vagueness of my last post, but my '85 SPG now has dash lights! Turns out my suspicions were confirmed...it WAS the rheostat. I just shorted those wires to give the lights constant full power (who uses that thing anyway, more problematic than helpful for me), and everything is just fine now. Thanks for the help though.
 

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Tyler said:
Sorry for the vagueness of my last post, but my '85 SPG now has dash lights! Turns out my suspicions were confirmed...it WAS the rheostat. I just shorted those wires to give the lights constant full power.
Well, it wasn't the rheostat, it was the wiring. If that had been mentioned:roll: I wouldn't have had to type so much.
 

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Discussion Starter #5
How was it the wiring? Seems like the rheo was grounding out or shorting or something, and when bypassed, all is well. Care to elaborate? Thanks again for the help, and next time I'll be sure to give you all the info first, to save you from typing so much. Wouldn't want to get carpel tunnel.
 

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Tyler said:
How was it the wiring? Seems like the rheo was grounding out or shorting or something, and when bypassed, all is well. Care to elaborate? Thanks again for the help, and next time I'll be sure to give you all the info first, to save you from typing so much. Wouldn't want to get carpel tunnel.
Oops, I stand corrected. I thought that you meant that you had bypassed the rheostat previously and reconnected it with this mod.

And, lighten up. I was kidding. Always glad to help.
 

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Discussion Starter #7
Haha, understood. Oh, and I was being very light, by the way, I guess I have a pretty sarcastic sense of humor. It's often lost on people in real life, let alone over the internet when tone isn't present. Thanks again.
 
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