So I got to drive my father-in-law Volvo and noticed that when turning the ignition key, the temp gauge shoots half-way up
and stays there, and the fan starts running when the engine is fired. Suspecting the temperature sensor as the culprit
I checked it, only to find the resistance in line with what it should be. I should mention that there is only one temp sensor
and not two or three as most sources state. The sensor is behind the alternator bracket, has yellow-black and yellow-white wires.
The yellow-black wire is the ground and it connects to the ECU plug, in fact there are multiple grounds there. To my surprise,
I found no terminal where the yellow-white wire, which is the signal from ETC I guess, goes to. The ECU pinouts diagrams
I found, show ETC wires going to 5/13 pins but this is clearly not the case here. I can see this Y-W wire in a bundle,
and it could be going to the temp gauge because it goes horizontally to the right.
At this point I felt I needed a correct electrical diagram and I gave up. The car drives all right but it bothers me not having proper
temperature indicated and the fan running on the cold engine. I suspect that the high fan speed might not function, either.
Any pointers would be greatly appreciated. BTW, this is an european model Volvo 940 2.4 tic, personally picked up at
Torslanda factory...