Rallye Gauge Failure

[smallblocksrock]

I am stumped.  I have a 1970 rallye dash and the temperature and oil pressure gauges do not work.   I have never seen them work.
I replaced the IVR with a new RTE IVR3.   I have 12V from the harness to the IVR. The output from the IVR to each post of the gauges bounces from 3-6v.  ( Should the output be a steady 5 volts?) The gauges will sweep with a direct 5V from a battery.  I tested the gauges in and out of the gauge cluster. 

I tested the gauges in the dash and also placed it on the fender using direct connection to the battery + and - and a direct line from the water temp sensor, which is new. Sweep hand does not move.

The IVR3 blinks as normal.   The ammeter is bypassed by soldering the wires together.   Gas gauge works.  Good ground wires from battery to engine to body.

I have the same result when I wired up another rallye dash.

Help!

[Chryco Psycho]

The power comes form the regulator , across the gauge & grounds through the sender so you can trace the power circuit all the way through

[1 Wild R/T]

Clearly the problem isn't the IVR or gauges...  With the gauges in place & hooked try grounding the wire to the temp sender & see if the gauge moves... Same for the oil pressure... If the gauge moves that proves the wiring is good & the sender is the problem... No movement means the wiring is the problem... 

[JS29]

 

[anlauto]

  That's where I would start, even a new temp sender can be faulty...

[smallblocksrock]

The grounding test showed both the water and oil sending units at fault.   I got the oil pressure gauge to work by swapping the oil pressure sending unit with a stock one.  btw, the PO had Autometer gauges.

I will replace the water temp sender again.  Not a lot of options.

Thanks everyone!