Temp gauge quit working on me last week, (fuel & oil pressure still work).

1. Using a 9V battery quickly across the temp gauge terminals causes the gauge to work.
2. Jumping the temp sender wire to ground does not cause a reading on the gauge.
3. The temp sender reads about 200 ohms to battery negative (engine not hot).
4. The temp gauge 5V lead shows conductive path to the pin on the dash harness (no crack in the circuit board).

I don't read pulsed 5V anywhere.....more like maybe 1, but its tough to read.
If my IVR is on the way out, will the temp gauge be the first to stop working?
How would you proceed?

Your gas gauge works so the IVR is functioning. From the batt test pretty sure the temp gauge is good. That only leaves either a sender prob or a wiring prob. You need the pulsed 5V to it just like the gas gauge has so if no go there attack the wiring & pull the round connector off of the back of the printed circuit flat panel on the back of the dash cluster & see if the open is upstream or downstream (in the copper printed circuit strips). Also check the bulkhead wire out to the sender but you said it is not getting pulsed 5V like the gas gauge so I'd work on the wiring from the IVR to the gauge

Yea, my DVM doesn't read that 5v signal well at all....
I jumped my fuel gauge to my temp gauge and the temp gauge responds.

I will likely make a "W" jumper cable to link all 3 gauges to 5v
as I'm not happy about $150 or so on a new board/IVR & cap.

Thanks