Temperature gauge does not work on my 1970 340 Duster ?

67Dart273 said
This indicates some electrical problem to me. Check block to body grounding, and CLUSTER TO BODY grounding. That is a known problem. The cluster is (poorly, OEM) grounded via the cluster mounting screws. Attach a ground pigtail to a ground point on the board, and bolt that to the column support.

One good way of insuring the block-to-body ground is good is to use a short "starter" cable, that is, eyelet to eyelet, bolted to the rear of the driver side head, and bolted to the firewall, or master cylinder mounting stud.

70Dustah, please note...I basically already followed the diagnostics from 67dart273 diagnostics with no success. If you follow all my entries, the gauge is good, the sensor is good, the wiring to/from the sensor is good, the sensor ground is good. I will add a good ground from the cluster to the column and from the body to the block as suggested, another redundant ground can only help. If it doesn't fix, not sure where to go next? thanks again for all your input and suggestions. No wonder aftermarket, mechanical gauges are so predominant :)