I own a 1995 Volvo 850 GLT Sedan (non-turbo)with 217K and still going strong. Just the other day the Ambient Temperature Sensor started to read 'HI' instead of an actual outside temp. Is there a way to fix this?

The ambient temp sensor for the dash temp readout next to the clock is not in the ducting for the blower motor. That sensor would be the ambient for the automatic climate control system. The sensor for the dash readout is on the drivers side up under the bumper, near the corner of the radiator.

The outside temp sensor is on the passenger side, in the air duct leading to the cabin blower. The sensor itself can be replaced, but you will have to lift up the plastic shroud below the windshield in the engine bay.

Klaus
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Please answer your responses. We need to know if the advice is good or bad. The 164 has a new home, all I am left with are 2 turbos :)

You must have misread this Klaus. However, I didn't know about the sensor you mentioned, and now I do!

Sorry for the misdirection. There are just too many temp sensors! Yes, on the driver's side of the large opening in the front bumper.
I have had my head in the books regarding cabin temp sensors, 2 on each side and the intake venting. Overkill.

Klaus
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Please answer your responses. We need to know if the advice is good or bad. The 164 has a new home, all I am left with are 2 turbos :)