OK everyone... I have been researching this issue for WEEKS to no avail, it's time I reach out to the community with my own problem instead of reading other people's. I acquired a very rough 1981 Volvo 242 about 6 months ago. Temperature gauge always read low to nothing... I replaced the senor twice with brand new ones from IPD, even ran a new wire to the cluster, still was low... finally replaced thermostat, the one in it was stuck open. So I replaced the thermostat 3 times all tested good in a pot of hot water but the gauge would show overheating with the thermostat installed, it would show low to nothing without it. I replaced the Radiator, all hoses, replaced the water pump with a GMB new unit. I replaced the fan clutch with an AISIN tropical unit... all of these are brand new parts. Still showed hot, not quite to the red but just near there, I have bled all air from the system. I then swapped clusters with an extra I had, still showed too hot, I then picked some extra voltage stabilizers from the local pick n pull still showed hot, ordered 3 brand new voltage stabilizers, still shows hot. I installed an aftermarket voltometer and temperature gauge, the capillary from temperature gauge is installed into the coolant drain plug on the side of the block under the exhaust manifold, the gauge never goes over 180 degrees F. coolant never boils. SHES RUNNING GREAT! Is it too much to ask for the coolant temperature gauge in the Volvo factory cluster to sit in the middle like its supposed to?? Does anyone know of ANYTHING else I should try?? I've cleaned my chassis grounds, the cable on top of the valve cover, everything! I'm about to throw an external voltage regulator from Dave Barton's website at but I doubt that will make any difference but maybe? Volts sit right under 14 volts running without any accessories. When I ground the wire to the temperature gauge it shoots straight to the red like its supposed to. I'm at my wits end.... I'm even looking at removing the gauge all together but don't want an ugly empty hole in my cluster. Fuel gauge reads accurately, temperature gauge is lying to me. I'm even up for installing a temperature compensation board from a late model 240 like what my 91 has.... If I could figure out how that is...