Reefer has difficulty to reach -10 temp

It's hard on older trailers with questionable units. Think of all the more reputable reefer carriers out there. You'll notice NONE of them run trailers older than about 4 years old. The guys pulling the old long ago retired Schaffer and similar trailers are the ones finding out the hard way about trying to deep freezing in summer with inefficient trailers.

And new reefer equipment is very expensive. Anybody hauling cheap temp controlled freight should be castrated for being that stupid.

 

TK SB- does same thing if battery is bad to protect from fail to start. No fault codes .