When I got my 89 244, the temperature gauge would waver erratically in the lower half of the scale and the heat was weak, so I figured I needed a new thermostat. I got one, installed it, the old one was indeed bad (typical failure---it came apart) but now the temperature gauge stays at the bottom and does not move. The new stat is working correctly, because there is now plenty of heat. I did some other work on the intake side of the engine today, so I suppose it is possible I dislodged the wire for the temp sensor. I'll check on that in the morning. Could it be anything else? I don't know if this car still has the compensation board or not.