Is this the temp gage?

[Axle Roads]

I removed the wiring for the temperature gage for a few months while I rewired the ignition and charging circuits. Hooking it up hasn't been a priority until more recently I experienced a problem at WOT (incr revs and loss of power) Now, I would like to rule out a cooling issue, but my temp gage still isn't working even though I plugged it into what I though was the correct terminal at the rear of the cylinder head, driver-side, shown below. I'm getting a 12 volts at the gage, but now I'm not sure weather the terminal shown below is for the temperature gage or for an old electric oil gage non-currently in use (I've always used a mechanical pressure gage on this car).

Where does the temp gage plug into the engine?

Is this it here, or is this the oil gage.

67 Mustang 200, C4

 

[Frankenstang]

Yep that's the water temp sensor (IIRC oil sensor is on the driver's side of block). It may be bad or the gauge could be bad...they're not terribly reliable. I need to replace my factory gauge or add an after market with temp readings.

 

[mach1 mark]

Axle didn't you just put in the DUI? If so are you sure you did it right? And if you were behind the dash, make sure your Instrument voltage regulator didn't get knocked off the back of the instrument panel and lose your ground. Or your IVR could be bad. If you are having multiple gauge problems it could be your IVR.

 

[Axle Roads]

I think were on the same page Mark. I just took my instrument apart to look at the IVR. I've never had one of these go bad before and I don't really know much about them. Is there a way to test them?

I'm thinking that I may have fried the IVR after the GM alternator swap. My 12si was bench tested at a a whopping 15.2 volts. I increased the length of my battery's charging wire to compensate, but I hadn't considered the stress the IVR would be under.

Today I learned that a few things are not working: The gas gage, emergency flashers, and I'm not getting power to some of the fuses on the fuse box. I forget how things are supposed to work down there. Is there a wire going from the IVR to the fusebox?

I poked around the IVR with a multimeter. The orange wire is supplying power ok. The blue wire and red wire receive power when the key is in the acc position. I didn't notice voltage on the brown or white wires. Does anyone know what this means. Do I need a new IVR?

I started out using a rigged test tight, until the bulb stopped working. I finished up my tests using the voltmeter.

 

[Axle Roads]

Maybe I should start a new tread since my original question was already answered.