On my 1992 W250 Cummins, I get no readings on my temp gauge. I have only had the truck about a month and the temp gauge has not worked since I have had it. Only driven it about 6 miles. In using the manual, I have located the air temp sender on the top drivers side of the block, to the left of the manifold. According to the manual, the coolant temp sender looks like it should be below this on the drivers side of the block. I have a wire/plug dangling down in this area and have not been able to trace where it should be plugged into. This may be my temp sender plug and just needs to be plugged in. Is the coolant temp sender up behind the fuel filter, in that general area and what color wires and plug are going into it? Thanks all.