# AC quit.



## HeathenCruze (May 11, 2020)

Everything in dash sounds, blows and looks right. Compressor clutch engages. Radiator fan doesnt turn on. think radiator fan/resistor crapped out. 
Lot of reading to find help. 
Unplugged fan and tried to use jumper wire to run fan direct. No luck. Tomorrow I want to try pulling relays and jumping there but not exactly sure which pins to jump.
Can you get fan out of there without tearing a bunch of **** apart? I see it done on gas motor but theres more stuff in here.
Sucks because Im 550 miles from home working for another 3 or 4 weeks its hot as ballz here and will be a long drive home without air.


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## snowwy66 (Nov 5, 2017)

The fan typically runs when high pressure gets high enough.

It comes on and shuts off.

They're not constantly running like the old days anymore.

Your compressor still runs. First thing I'd check would be the low and high pressures. Make sure you're still fully charged. Before trying to diagnose electrical.


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## HeathenCruze (May 11, 2020)

Fan doesnt turn on when air/compressor is on?


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## snowwy66 (Nov 5, 2017)

Not till high pressure gets high enough.

It works in the same manner with the ac as it does with radiator temperature. 

On off on off.

It's not needed while driving down the road.


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## snowwy66 (Nov 5, 2017)

IIRC. On my 17 cruze it kicks on about 315 psi and shuts off about 260 psi on the hi side.


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## HeathenCruze (May 11, 2020)

Thanks for info. Thats not what I had been reading.
Have a bluetooth obd2 coming tomorrow. Do any of the apps show those pressures?


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## snowwy66 (Nov 5, 2017)

Torque pro has a high pressure gauge for the ac.


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## Snipesy (Dec 7, 2015)

The cooling fan relay system is something else. That's the nicest way I can put it.


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## HeathenCruze (May 11, 2020)

Cant find the **** thing on torque pro.
What temp should fan turn on? 
Apologize for stupid questions but theres so much on this forum that searching and reading leads to a thousand dead ends and google searching doesnt give **** for diesel info.


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## HeathenCruze (May 11, 2020)

Found it.
Reading 153 so I guess its needs a charge?
Temp got 197 and no fan with or without air turned on.


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## snowwy66 (Nov 5, 2017)

A fully charged system will be 260 with fan on.

Course. Fan shuts off around that point.

Engine at 2000 rpm. You want driving conditions as that's what the car does. Not idle conditions. 

You should have a gauge set though. Make sure low pressure is working properly with hi pressure.

I'm also not vouching accuracy on torque. I haven't compared it to my actual gauges set.

Make sure engine at 2000 when charging ac.
I have no idea on fan temp for the diesel.


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## HeathenCruze (May 11, 2020)

Thank you all for the help. The car is pretty new to me and loke I said, long ways from home living in a hotel tryong to figure it out. Its a good little car, loaded and 55,000 or so miles. 
AC was blowing cold in morning then when sitting in hotel lot after work it got warm. Thats and fan didnt turn on so I went more for electrical issue than low pressure. 
This bluetooth obd2/app thing is sweet! Cant beleive I didnt know about it till a couple weeks ago.


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## HeathenCruze (May 11, 2020)

And the low side pegged the gauge.
High side 141lbs.
Thats not good.


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## snowwy66 (Nov 5, 2017)

Bad compressor or expansion valve possibly. 

What does the pressure read when it's stabilized and hasn't ran for a few hours?

I say few hours because these days they take their sweet time equalizing after shutoff.


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## MRO1791 (Sep 2, 2016)

Be sure to get Snipesy's "BiScan for GM" app plug in for Torque, or the "Gretio" App. It has many Gen 1 Diesel funtions and gauges in addition to the standar Torque Pro options. If you have questions, he's here on your thread.


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## Snipesy (Dec 7, 2015)

I'll be honest I have never heard of anyone using the high pressure sensor PID to diagnose it before. Get some manifold gauges and hook up direct.

The most useful PID there is in my experience is the "A/C Disabled - A/C Pressure Out of Range" PID which tells you if the compressor has been disabled to protect itself. This is almost always the case when a compressor is not turning on, but in your case the compressor is turning on.

Now just because the compressor is turning itself on doesn't mean the system is low on refrigerant. It just means its not low enough to trigger the self protection... I don't know the exact number but it's pretty low to trigger the protection.

For the cooling fan it will directly tell you if the relays are enabled or not which is useful. While GM does allow us to directly control these relays with the tool they are for whatever reason disabled when the vehicle leaves the factory.... (really GM?)


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