Part time ac (1 Viewer)

Joined
Dec 27, 2018
Messages
56
Location
Louisiana
I have a 94 LC 80. It has part time ac and i cant figure out why. In the morning it will blow its butt off really cold. As the morning goes by it gets warmer and warmer. Then all of a sudden its back cold again. I have no idea why this is happening. FYI I installed a new compressor a few weeks ago and everything has been fine.
 
Joined
Feb 28, 2017
Messages
166
Location
Midland
I had a similar issue and it was the #2 sensor in the picture below:
1623170819569.png


You can get to it with the intake on. Disconnect the wire going to that sensor. If your AC cutout problems stop, that sensor, or your coolant temp, is the problem.

Here's the part number for the sensor: 8879060050

It's not too tough to replace with a deep socket and the right extensions. Mine leaked about an ounce of coolant when I swapped them.
 
Joined
Nov 7, 2006
Messages
1,264
Location
Tucson, AZ
The most common causes are the engine temp high enough to cut out the a/c or the expansion valve. It could be some thing else, even low refrigerant could cause it.
 

flintknapper

SILVER Star
Joined
May 22, 2004
Messages
10,189
Location
Deep East Texas
I have a 94 LC 80. It has part time ac and i cant figure out why. In the morning it will blow its butt off really cold. As the morning goes by it gets warmer and warmer. Then all of a sudden its back cold again. I have no idea why this is happening. FYI I installed a new compressor a few weeks ago and everything has been fine.

Diagnosing intermittent cooling should generally begin with reading the system pressure (high and low side) using a manifold gauge set.

Can you tell us more about the new compressor installation? Who recharged the system and was a vacuum pulled on it first?

Any Orings replaced, oil added, etc....?
 
Joined
Dec 27, 2018
Messages
56
Location
Louisiana
I had a similar issue and it was the #2 sensor in the picture below:
View attachment 2697949

You can get to it with the intake on. Disconnect the wire going to that sensor. If your AC cutout problems stop, that sensor, or your coolant temp, is the problem.

Here's the part number for the sensor: 8879060050

It's not too tough to replace with a deep socket and the right extensions. Mine leaked about an ounce of coolant when I swapped them.
Thanks alot for the info.
The most common causes are the engine temp high enough to cut out the a/c or the expansion valve. It could be some thing else, even low refrigerant could cause it.
Its a new compressor and refrigerant. Im leaning towards the expansion valve. Thats what everybody is picking too. Thanks
 
Joined
Nov 7, 2006
Messages
1,264
Location
Tucson, AZ
Then I would suspect the expansion valve. If you have gauges hooked up when it quits cooling, if you see the low-side go to zero or into vacuum, it's the expansion valve.
 
Joined
Dec 27, 2018
Messages
56
Location
Louisiana
Diagnosing intermittent cooling should generally begin with reading the system pressure (high and low side) using a manifold gauge set.

Can you tell us more about the new compressor installation? Who recharged the system and was a vacuum pulled on it first?

Any Orings replaced, oil added, etc....?
Not sure about that stuff. Ill give the ac guy a call when i get home. Thanks everybody
 

Users who are viewing this thread

Top Bottom