AC SOS

[Vik1318]

Hello Group,
I’ve been fighting my ac for longer than I wanted to . Have replaced 90% of the parts and I’m still having the same problem. Once temperature reaches above 90degrees engine fan (ac)stays constantly on and eventually shuts the ac down. Parts that have been replaced are condenser, expansion valve, compressor, evaporator including evaporator sensor, bmc. The system has been vacuumed and refilled.
I’ve also noticed my ac compressor only cycles when it’s cooler temps outside as well. The only other few parts I can think of are ambient sensor ( don’t know if it plays roll when it comes to the ac system) also ac relay.
TIA

[Rawze]

what year, make, model truck?. what engine?

[Vik1318]

(07-08-2024 )Rawze Wrote:  what year, make, model truck?. what engine?

2014 prostar with ISX

[Rawze]

(07-08-2024 )Vik1318 Wrote:  

(07-08-2024 )Rawze Wrote:  what year, make, model truck?. what engine?

2014 prostar with ISX

this will help...
https://rawze.com/forums/showthread.php?...4#pid77574

[Vik1318]

(07-09-2024 )Rawze Wrote:  

(07-08-2024 )Vik1318 Wrote:  

(07-08-2024 )Rawze Wrote:  what year, make, model truck?. what engine?

2014 prostar with ISX

this will help...
https://rawze.com/forums/showthread.php?...4#pid77574

I have replaced 5amp fuses. Is there ac relay if so where it’s located? Going to check ambient sensor . Felt like it’s something electrical related because it’s only does it when it’s hot outside. Seems like when it’s compressor starts working harder that’s when all the problems start.

[Andre_The_Giant]

Did you try a new Temp probe in the evaporator? If it’s reading wrong it could be the problem. The hotter the ambient temp is the better and AC system should work, if the evap is freezing or if computer thinks it’s freezing it will shut the compressor off

[Andre_The_Giant]

Did you change the receiver/drier? If there is moisture in the system the evaporator will freeze. Always use a new receiver dryer

[Vik1318]

Yes everything got replaced. Low and high pressure switches as well including evaporator probe. . Right now it’s about 92 outside ac works my compressor constantly running with bunk ac on including my ac fan.

[Andre_The_Giant]

Maybe the new high pressure switch is no good? Next time it shuts down on you jump the switch and see if it kicks on