[Roadsters] Under dash Voltage regulator

[John F Sandhoff]

> ...At present my fuel level gauge and temperature gauges are not
> working... My wiring diagram shows that these gauges and all
> going back to a voltage regulator under the dash.

Hi Jeff,

It sounds like you've now located the voltage regulator. So here's some 
troubleshooting tips.

 This is a bimetallic strip/heater that creates a pulsing voltage
of zero and battery (nominal +12 to +13.2). Three terminals, but only
two are wires as the case is the third wire and is grounded. If the
ground is bad (case not mounted, corrosion on case/screw, etc), the
voltage will stay high and the gauges will read way high. If the two
wires are reversed, the gauge will start to come off zero briefly
(a few seconds), then fall back and stay at zero.

Troubleshooting: With ignition ON, check for steady +12v on one
terminal. That's the input. If it's missing, the problem is upstream
(bad wire, fuse, etc).

Then check the other terminal for pulsing voltage. If you have it,
problem is downstream (since both gauges are dead, unlikely two
bad gauges, so a bad wire). No pulsing? To check for reversed wires,
simply... reverse the wires.

If you disconnect both wires, you should read near zero ohms across
the two terminals of the regulator. If you don't the internal contacts
aren't making contact (bad regulator).

-- John
     John F Sandhoff   sandhoff at csus.edu   Sacramento, CA