Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Hi Im David, usually when the ac cycles like that its an indication of low refrigerant levels. Have your refrigerant level checked. when was the last time you had the ac serviced?
ok. when you turn the ac on, does the cooling fan kick on?
there should be an electric fan snug up against the radiator
usually there is 2 fans. one for the engine temp to keep it cool and one for the ac to keep air flowing through the condenser to keep the ac cool at idle
it should look like this
ok good, then next check the front of the condenser for blockage of debri and dirt.
yes that would be it. ok. my advice to you would be to have the refrigerant level checked. that is a must before going forward.
yes manifold gauges...
what you will be looking for, with the car shutoff. low pressure should read about half of the ambient air temp i.e. if it 80 degrees out the low pressure gauge should read approxiamately 40. and the high pressure should read approximately double the temp i.e. 160
that would indicate a good charge
then start the car put the ac on max and watch the gauges. low pressure should drop to around 20 then kick back on and go up to 40, then then the high side should go up to 250-300 then kick back on and drop back to 160
that the radiator fan is turning faster and is helping cool down the condenser as a supplement to the condenser fan.
just let it idle dont worry about revving it. then let me know what the gauges go
do you have the valves open at the service port connections
my bad. how hot is it where you are?
is the compressor cycling?
ok. gimme a minute and let me look at my manual
what size engine is in that thing?
ok. now, turn the ac off of max ac and set to regular. tell me if it cycles then.
ok, thats ok. just sitting with no airflow across the condenser im not surprised its not cycling
if you shut the truck off anf let the pressures bleed down, what readings are you getting? let me know. itll take a while for the pressures to bleed all the way off.
because of the outside temp and the fact that its sitting idle with no airflow across the condenser, the compressor will run constantly trying to keep the passenger compartment cool.
do you still need assistance?
some dont have the extra electric fan ,apparently yours is one of them. I know that people install them as a supplement to the radiator fan in hot wether climates though
if you did have one it would be mounted snug up against the radiator or in front of the condenser
well the radiator fan is supposed to be sufficient enough to coll the radiator and the condenser while sitting at idle
A fan clutch is as reliable as any other component on a vehicle, yet sometimes they fail. A common symptom of fan clutch failure is overheating at idle or in heavy traffic. Bad fan clutches can also cause poor performance of the car's air conditioning system because the fan also cools the air conditioner's condenser, which is directly in front of the radiator. A fan clutch can also fail in a stuck on position where engine power is lost even when the fan is not necessary. This type of failure can also decrease fuel economy.