2000 Frontier AC


#1

I have a 2000 Nissan Frontier that is a 4X4 and has the V6 engine. Mileage is 172,000+. For a few years, I have had problems with the AC no longer cooling after I drive 20 or so miles and stop the truck, go in a store and start back up only to find that the AC will not cool after the stop. This seems to happen more when the weather is hot. Only once has it gone out without stopping the car and it was on I40 driving trough Oklahoma in 100+ degree weather. Once it quits cooling, after driving 20 to 30 minutes, it usually starts to cool again. It sometimes speeds up the process if I roll the windows down.Coolant levels are fine.

So…is there a faulty sensor somewhere? What could it be that is the problem?


#2

I am no expert, but I will take a shot in the dark. Does your Nissan have a fan clutch for the radiator fan? I had a similar problem with a 1990 Ford Aerostar. It turned out that the fan clutch slipped too much and wasn’t turning the fan fast enough to pull the air through the radiator and condenser.
My shop found the problem by running the vehicle until the air conditioning stopped putting out cold air. The mechanic hooked the gauges too the air conditioning system and the pressure was sky high. He then directed the flow of air from the shop fan through the radiator and condenser. The pressure immediately went down and the system began cooling again.
When you stop, the heat from the engine kicks the temperature of the coolant way up. If insufficient air is flowing through the radiator and condenser, this might be the cause of your problem.


#3

The AC compressor in your truck has a thermal protector mounted on it. This thermal protector cuts power to the compressor clutch if it senses that the compressor is getting too hot.

It could be that the thermal protector is faulty, or the compressor is actually getting hot enough where the thermal protector is cutting power to the clutch.

Tester


#4

Those sound possible. Thank you both. I’ll have to check into each suggestion. I think however my fan is direct drive - simple enough to check out on that.