AC relay location

there is no relay usually from my knowledge this is controlled by sam cab and also your hvac controler, usually thats the problem when a/c is fully charged and all sensors working properly if you have dagnostic link you can check a/c request and what is happening in the a/c system as far as sensors and everything go.

 

Find the low pressure switch,disconnect and use jumper wire to disable the switch temporarily..this is a kenworth version.

 

can't do anything with pressure switch on cascadia, run jumpers from alt to ac and feed it power and ground this will make it run. just go directly to compressor. this will also help you check if you have a charge issue or electrical issue. just for ####s and giggles check your condenser very notorious for leaking on cascadias.

 

Cascadia SAM Chassis....... drive this truck to the river. I was a fan of Freightliner once, but now I am going Volvo all the way.....

The only good Cascadia is the Glider one, because has the custom harness, no SAM Cab CRAB...

 

I have a 2018 cascadia, the air conditioning has been acting strange, first replaced the high pressure switch that wasn’t the problem now the compressor and clutch both replaced, that didn’t fix problem. The air works great until you hit a bump and then it goes out and the fan clutch engages and runs for several mins.

 

You prob have a loose connection somewhere, prob by the ac compressor assy, check the compressor connection pins and high pressure sensor pins.