Tractor - What's that cooler cooling?

[paulo57509]

Errands took me out to Stockton this afternoon. I noticed more than a few tractors without trailers on I-5.

Most had a cooler mounted on the rear-center of the (non-sleeper?) cab. What is this thing cooling? A/C, engine oil, trans oil, differential?

 

[skyactiv]

Condenser for the APU system.

 

[skyactiv]

Just noticed you said non sleeper. But plenty of day cabs sit around at facilities waiting to be loaded and unloaded. The drivers aren't going to shut the truck off and sit for 3 hours with the windows down to save the company money on fuel when its hot out. And the cheap companies that have auto shutdown either better pay out the wazoo for wages or else have an even higher turnover rate that has always plagued trucking comnpanies.

 

[Tow motor]

I imagine it is an auxiliary a/c to comply with California’s idle ban.

 

[Chris142]

It's a condenser for ac when parked.