A/C would be cool for 5 minutes and then gets hot?

1993FORDBOY88

MEMBER
2017 HYUNDAI TUCSON
2.0L
4 CYL
2WD
AUTOMATIC
53,882 MILES

I'm noticing that my coolant fans will not operate. I'm not overheating, and I tend to idle for long periods of time, and they never turn on. I understand that if they don't turn on then the A/C won't turn on in most cases. When I turn the car on and select the A/C from the HVAC module I'm only getting 2-5 volts at the compressor which I think would be high resistance in the circuit or its the module not allowing the compressor to come on due to the fans not turning on. I replaced the evap thermistor near the gas pedal and I've swapped out A/C relay under the hood of the vehicle. My gauges are reading static pressure at 100 high and low since the compressor isn't turning on.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
42,940 POSTS

There are 9 fuses that run the system. We need to check those first, also please remove the power lead at the compressor to see if it goes to 12 volts, if so, you have a shorted A/C compressor ECV Valve. This is not the typical clutch style compressor; it uses a variable valve. Here is a guide to help you test the fuses and the AC/HVAC wiring diagrams so you can see how the system works and which fuses to test:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If the voltage jumps to 12 volts here is how to change the AC compressor it out as well. You will need to handle the refrigerant as well; this video will help:

https://youtu.be/4EqdrBVb0sY

We might want to run a CAN scan to see what codes it pulls; you can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

and

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Here is one for about $99.00 if you need it:

https://amzn.to/3ZixY4v

Please check out this guide to know how the compressor works

https://www.2carpros.com/articles/detailed-guide-on-the-functionality-of-an-automotive-ac-variable-swash-plate

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