Ford 4500 Instrument Cluster

[Ray T.]

I am try to get my Instrument Cluster working again.

When I apply 12 volts to the B terminal on the Voltage Stabilizer on the back of the Instrument Cluster all of the other terminals on the Instrument Cluster show they are energized with 12 volts.
In fact it looks like the entire Instrument Cluster Housing is energized with 12 volts. (12 v to B terminal and positive lead from Volt Meter to case with negative lead on ground shows 12 v).

I assume this is not correct and the case itself should not show any voltage? I also thought the Voltage Stabilizer should reduce the Voltage to about 10 v.

Does anyone know how to test the Voltage Stabilizer and should the entire case show power?

I did put a ground on the Fuel and Temperature terminals with the Instrument Cluster energized and they both moved from low to high so they appear to be working properly.

 

[Bern]

The case should not show power - it sounds like you have a bad ground.

To test the voltage stabilizer, power it up and wait at least 30 seconds. Meter should show an alternating 12-0-12-0-12 etc. volts. This assumes there is current going to the gauges (i.e. the gauges actually work). If there's no current flowing through the gauges, the voltage stabilizer will not function. It essentially acts similar to a turn signal flasher unit. If you used a 12 volt test light to check it, the test light should flash on and off. This is how the voltage is regulated to the gauges.

Try doing the majority of your testing with a 12 volt test light. You'll likely get some different (and less mystifying) results.