new temp gauge problems please help

[srs244]

part of the entire restoration of the interior on my pace car includes replacement of the center console gauge cluster. i rebuilt the entire assembly using all new gauges, and a new circuit sheet. i tested it today and everything works fine (even the clock) except the temp gauge which is a completely restored original unit from redline gauges. when powered up, the pointer is exactly reversed from what it should be ie: it sets on the right side of the scale toward pegged hot, instead of on the left side of the scale as cold. other than the obvious that the gauge is defective (it is supposed to have been bench tested after the rebuild to insure it was working well), what could it be?? the gauge cluster (the old one) that i am removing had a properly functioning temp gauge, so i am assuming that the wiring to the panel (from the wire harness) is functioning properly. i am looking for some help before i tear it all down and start all over again blindly.

thanks

[JohnZ]

With the key on and the connector disconnected at the sending unit, the gauge should peg to full cold; with the connector grounded to the engine, the gauge should peg to full hot. How does yours respond to this check?

[pgtr]

I've seen this once or twice on other cars and in those cases it's been a grounding of the signal wire or circuit from the sending unit.

[bmotojoe]

I know on the 1977 model there is a Red 85 ohm calibration resistor bolted to the gauge under the flex circuit board. An bad wire or a defective flex circuit board will keep the gauge at rest. Ground the end of the sensor and the gauge will peg to the right.
Sensors must be grounded through their threads to the block to work. It is not recommended to use Teflon tape for sealing them.

[srs244]

thanks for the suggestions. the printed circuit sheet is brand new and has no breaks or cracks and is completely in tact. i am going to dis-assemble the cluster this evening and take a look to insure i placed the resistor on the gauge correctly and make certain there is correct electrical connections and try again. since the gauge isn't pinned to the right (it appears to be functioning backwards, positioned just off the pinned position like it is registering from the right side of the gauge instead of the left), i assume it isn't totally grounded out (although it might be). all things to check out. i'll let you know how i make out when i solve the problem.

thanks