Air conditioner sometimes doesn't put out cold air

Maintenance/Repairs
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1

I have a 1996 Toyota Tacoma, 5 speed manual pickup. Love it!

Occasionally I use the air conditioner. I’ll be driving along and it’s working fine but then it stops putting out cold air. I pulled into the mechanic one day and confirmed that when it is not putting out cold air, the compressor still seems to be running.

If I go into a store for about 15 minutes and then come out again, it works again.

Any idea what might be happening? I want to know more before I go to the mechanic so that I can ask intelligent questions.

Thanks in advance.

Rita

2

I had a variable resistor blow out on fan speeds 1 and 2. In my car the fan noise is undetectable at those speeds. It was plenty cool on the highway but ineffective at slow or stopped. Took me a bit to figure out the blower fan was not working. Replaced the resistor and everything was cool.

3

Your evaporator (cooling coil) may be icing up and preventing the air from flowing through the coil. When you turn off the vehicle for a few minutes the ice melts and the air flows through the coil again.

4

The problem might be with the expansion valve at the evaporator.

This is what creates the cold air from the refrigerant.

These expansion valves wear out over time and heat where they no longer properly control the refrigerant pressure. So no cold air.

But a set of manifold gauges is what’s needed to determine that.

Tester

5

+1 - Low on freon.

6

+2…low on refrigerant.

7

+3 low on refrigerant

The system is 19 years old. Take it to a qualified AC shop, have it checked out (they’ll probably find a leak), and have it repaired correctly.