Fuel and Temp Gauges Quit - 1965

[Rickmustang]

Went for a drive today and neither the fuel or temp gauges worked. Is there a resistor on the rear of the instrument cluster housing that has probably gone out? I know there is a part on the rear just don't know what it controls. Thanks.

[SFM6S087]

I'm not sure about a regular 1965 dash cluster, but the 1965 5-dial GT cluster (along with the 1966 cluster) has a voltage regulator on the back of the housing that will affect the fuel, temp and oil pressure gauges. If it is out of whack it can cause all three of those gauges to read too high or too low. If it goes bad altogether it would probably stop all three of those gauges from working.

Replacements are cheap and it's not a difficult swap, so you might start there. Here's a link to one of those at Virginia Classic Mustang. That's where I bought mine.

http://www.virginiaclassicmustang.com/65-66-INSTRUMENT-PANEL-VOLTAGE-REGULATOR-NEW-PRECISION-ELECTRONIC-STYLE-P8420.aspx

Steve

[KR Convertible]

I just put one of those (same brand, bought from VA Mustang) in a 65 convertible project I've been working on.  Be careful pushing the spade connectors on.  They were very tight and the connector came off of the rivet on the constant voltage regulator.  Of course this happened on a Saturday afternoon, so I decided to solder them back on and hope I didn't wreck it.  I also ended up filing the spade connector, it was a little too wide.  I'm not sure if the problem was caused by the harness or the CVR, both are reproduction parts.  Thankfully, it worked after all that or I would have been out $20.

[Rickmustang]

Thanks Guys.

[Steve McDonald Formally known as Mcdonas]

The circuit works on a pulsed voltage, take either the temp sender wire or the gas sender wire, check with a test light, it should have a blinking signal. If not the voltage regulator on the back of the instrument cluster is bad. Follow the instructions others have written to fix. If the link blinks try the following If you ground the gas tank or temp sensor wire gauge will peg to full or hot depending on which gauge you are testing