1977 Pontiac Firebird A/C runs on High

Hi Brian, What you are explaining to me is that the fan will not go on med or low, but just runs on high. Check the connections behind fan control switch. If a wires is dirty or correded and making bad connection the fan could work on high alone or the switch itself could be bad. Check the wires first. The same if the wire for the high was not connecting then the fan would work on low or med. Put the fan control on med and I found moving the wire harness by the switch behind the dash, around some usually will help tell if there is a bad connection. If the fan speed changes then you have found the problem.

It is possible a relay could be bad, my wifes car at that time had a bad wire that kept her heater from changing speed and found the problem, by the speed control switch. All the wires needed was to be put on. Someone years ago had did some work on the car before she got it and the heater switch contol wires were not on completly. If that does not work get back to me.

How did you make out with the temp control? What does the fluid look like that is leaking and see if you can tell what area it uis leaking from. Pwere steering fluid would be by the front of the engine and transmission fluid redish in color could be leaking from anywhere from the radiator to the transmission. With that year of car I would think it is in the transmission line that is leaking. If the line is leaking and in a spot that is accesaable you can repaor it with ! A new line @get rubber tubing with two clamps and repair it that way.

The stickers can be waxed, but use caution around the edges. With the sticker that old, sometimes the stickers loose some grip around the edges.