74 Barracuda Gauge Problem

[CUDAMAN1970]

Started my 74 Barracuda with Ralley Gauges for the 1st time today.  Car starts up and runs fine but alternator gauge flickers and all other gauges do not function.  My mechanic neighbor is helping me with the project and he tried to ground the temperature and oil pressure gauges and the effort had no effect on the gauges.  Removed "black" wire from connector and alternator gauge no longer flickers but other gauges do not work.

Head lights and fog lights work - car starts right up and all fuses are good. 

Any ideas?  What could be causing the problem?

Thanks!

[Bullitt-]

Sounds like you may have a bad instrument voltage regulator.. Grounding wire from sending unit is a good method to test gauges but they need + power to.
http://www.allpar.com/history/mopar/electrical2.html


Replacement solid state available
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[CUDAMAN1970]

Sounds like you may have a bad instrument voltage regulator.. Grounding wire from sending unit is a good method to test gauges


We did some more testing today and found that if we took power away from the fuel gauge, the oil pressure, alternator, and temperature gauges work.  We tested with a different voltage regulator from another cluster and got the same results with either.  Looks like we are going to have to pull the cluster. 

Anyone haver any suggestions . . . .

[72rtchallenger]

did the fuel gauge work before it was unhooked

[CUDAMAN1970]

Fuel gauge did not work before or after.

[72rtchallenger]

maybe the sending unit in the tank is bad maybe shorted out,, or the wire to the tank is shorted out,,use a muti meter and see if its shorted out to the frame somewhere