temp gauge

[Pete]

Terry, I think there is a plug in Ballast resistor (or similar) that affects all the instruments; maybe the contacts are corroded.

Alex will be able to advise you. He LOVES doing Mopar Dashboards.

[Alex]

All the instruments are earthed through the dash frame, the ballast is also earted through there, as are the dash bulbs, if the dimmer is effecting things the dash may be earthing through the dash bulbs, check all the grounds first and see if there is a pulsed +ve at the switch wire