Problems with ThermoKing Legacy 650 APU

My control panel has buttons instead of knobs. But it's a standard TK control panel, and the TK tech (actually the shop manager, very knowledgeable) told me specifically how mine should work (just like you said, except with buttons), but it doesn't. Thing is, I got screwed pretty hard by the guys who did the refurb/install, so there's no guarantee they did it right. I had to go back eight times in the first year for warranty work. It never worked for more than a few weeks at a time, and it's my first APU so I never had a great idea of how a good one should work either.

The truck does not seem to lose juice with the APU off. These new batteries are holding a charge for like 24 hours with me running the bunk heater as well as my laptop and monitor. With the old run-down batteries it might give like 3 hours of computer and seven more of just bunk heat, so I could MAYBE get thru a 10 hour break if I had driven all day. If I would turn on the APU standby, it wouldn't last more than a couple hours before first needing to charge, and then it would need to run about 30 minutes out of every 60 to keep the charge up. If I let it charge the batteries, then shut it off when it was done, they could go for a couple hours.

It was only recently that I figured out that it was running way more than it should. So for a long time I would shut down and turn the APU standby on right away, because I didn't realize it shouldn't need to run as much as it did. It wasn't until the past few weeks that I finally started waiting until I needed it before turning it on, and thats when i finally started noticing how much better the batteries held up with it off.

 

TK tested the alternator, they found the output to be normal. When you say Tripac battery terminals I'm guessing you mean the wires connecting the Tripac to the truck batteries. They checked those and even moved them to the strongest battery, but it didn't improve performance.

 

Nice, that's my control panel. That video is a little unclear on one thing though. It describes the null mode as cycling thru all the functions until none are selected, but in part 1 of the same video it seems to say that the same mode is active by simply pushing the left and right buttons. This latter method is exactly what the TK tech told me about, and the installers told me about it too back in the day, but it's never worked. My guess is cycling thru the modes just puts it back to the original position with no mode selected, the same null mode either way, but the video seems to accidentally make it seem that they're two different settings. If you or anyone else knows different, I'm all ears, of course.

 

That was my exact impression. At first I felt maybe it meant my problem was unsolvable or too petty to be worth the necessary attention, although the devil's advocate in me was certain that there must be something wrong with the level of service when you're telling someone about your problem and the focus of their replies is that it can't be happening.

 

Thanks man. If nobody comes along with a recommendation closer to my normal stomping grounds then I'll definitely make it out that way before long. Although I will note that I had been getting the cheap batteries before, but this latest set the guy behind the counter was new and just rang me up for the OEMs (which i didn't realize because they were on sale), and I'm really surprised how much better they're doing than the cheapos did.

 

Lol I figure that I already exceeded the cost of a new one just from all the destination freight and downtime involved in getting it serviced under the one year warranty.