Questions and Answers

Chevrolet Silverado Not Hot Or Cold Q. My heater nor my air conditioner work. 1991 Chevrolet Silverado ¾-ton. I just bought this truck. I had one mechanic look at it and he told me to replace the thermostat. My son checked the A/C and it appears to have some freon in it, The fans blow. When I put it on cold, the air is a little cool. When I put it on hot, the air is a little warm. What are the different things that could cause either not to work properly? Thanks, Ellen

A. For heat you need a full cooling system with no air pockets. The thermostat is the first thing to check if the cooling system is full. The A/C may not work well on colder days. You need to look at the compressor to see if it comes on when the switch is on A/C. It may just be low on refrigerant which would indicate a leak in the system.