Corsa Dash Temp gauge Troubleshooting guide

This is for 65-66 dashes. EM Spyder dashes will be the same except for Wire color / placements

System Check with COLD engine:


1 with key "ON" is gauge"

Always over 600 f = good 12vdc to gauge / no ground

Rises to over 600f = shorted lead to Thermister / shorted T-M.

Needle moved but under 200f = gauge funtioning / open circuit to thermister / T-M bad

Thermister / wiring checks

2 wire plug behind dash / Black with light green stripe should read 4,000-6,000 ohms to GROUND

High Temp lead from T-M should read 4-6k ohms

Thermister should read 4-6k ohms

Gauge Checks

With Dash Harness unplugged:

Black / lt Green wire to dash [ 2nd pin in from row across from open hole] to Black / Purple wire in plug [ 2nd pin over from empty hole]

should read 50 ohms [ gauge good ]

with dash harness pugged in / key ON and T-M disconnected you should see 10 VDC clear

back to T-M.