I may be done with Thermo King APU's

Mike

Well-Known Member
So, here we are. Third new truck, all equipped with new Thermo King APU units.

The current unit has been in service for roughly 14 months, and as with every other unit I have had experience with, the alternator dies an early death. I'm not positive, but I "think" the unit has a two year warranty, but it doesn't really matter at this point. These alternators should last longer than this. If they are simply being overworked by hotel loads, then there needs to be a larger replacement.

Got my first shutdown yesterday shortly after I parked. It was fairly warm in the truck, the trucks on each side of me were noisy as hell, and I had to go to sleep early in the day to get up and finish out my run. APU ran for about 5 minutes with the air conditioner running and shut down.

Wasn't so bad, the sun was setting soon, and the temps were going to drop down into the upper 30s. Once the temps cooled down, the alternator worked well enough to charge the batteries overnight.

Today, not so lucky. Delivered in Blythe, CA early this morning, and by the time 0900 hit, so did 90 degrees. Bounced over to the truck stop to clean out the dirt and rocks from my trailer after the solar panel delivery, and was greeted to alternator failure. Tried it a couple times and gave up.

Luckily, I had the truck equipped with optimized idle when I purchased it. Works great other than if the invertor is on, which it will be overnight, the low voltage alarm sounds off when the truck is cranking. Fat chance sleeping through that.

And, I had my first parked regen today thanks to all of the idling. That scared me a little when it happened. I dealt with one parked regen in my life prior to this, and it was 10 years ago. Got out of the truck while that was going on, and the heat being generated under the truck was enough to make me want to get this alternator situation fixed ASAP.

It will be a while before I have to make this decison, but I will definitely be spending some time over the next 3-4 years researching other APU options, may even go with a battery powered and solar panels.
 

mndriver

curmudgeon extraordinare
Get your batteries tested and likely replaced.

Every time I’ve lost an alternator, my batteries were also toast.

I also get my alternator from thermo byproducts for half the cost.

Yes, I just replaced both my batteries on 2/9 and my alternator last trip out.

My alternator had 6500 hours on it.

Most thermoking dealers have 9-12 alternators on hand…. For a reason…

07F1C7B8-6509-41C8-8F2A-EB64E4DA81C9.jpeg

This is my second set of batteries since 9/20 when I put the truck into service. I even put a battery maintainer on them when I come home as well. So it’s got a charger on them constantly in the back yard.
9DE840D5-37A0-4C85-997C-4AFCD83EF3AE.jpeg


If you don’t have it, I’d recommend getting the tripac software and adjusting some of your settings for your benefit. I was able to run an alternator service test and see my new alternator put out 90 amps peak charge. I have to go back in and clean up some terminals and likely replace a terminal end due to corrosion. I can’t do anything to stop it after 7 years because of the actual environment it sits in getting all the fine road spray
 
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Mike

Well-Known Member
Get your batteries tested and likely replaced.

If it were once instance, I could see that. I can almost set my watch to 1 year for replacing alternators and this is three trucks in a row now.

One key upgrade that needs to happen is a manual startup. It should be the simple flip of a switch to start up the APU and let the alternator start charging before a major battery draw triggers it.

And they simply need to improve the alternator.
 

mndriver

curmudgeon extraordinare
I gave my old alternator to my parts guy and he’s looking for an actual Bosch alternator for me.

It’s a simple process to put a manual start switch in. Put a switch into the Arctic sensor wire and bam. Manual override.

Or you could go in with the software and just change the voltage threshold for when it starts to charge. It’s under the programmable settings tab.

This image is when I was running the alternator service test prior to replacing the alternator. Took about 45 minutes. Spent more time getting tools out and putting them away.
8659535D-6B43-4B2D-8AFE-ACC7D0882BE6.jpeg


My positive terminal is corroded enough, it puts out 14.3 volts at the terminal and 14.0 at the batteries. Pretty sure I have a cable that needs to be replaced.
 

Electric Chicken

Well-Known Member
Premium
If it were once instance, I could see that. I can almost set my watch to 1 year for replacing alternators and this is three trucks in a row now.

One key upgrade that needs to happen is a manual startup. It should be the simple flip of a switch to start up the APU and let the alternator start charging before a major battery draw triggers it.

And they simply need to improve the alternator.
My dad went through something similar with his Dodge pickup and starters. They were undersized and died almost like clockwork. He went through 3 of them in about 3 years before getting rid of the truck.

In conclusion, I'll give you 2500 bucks for your Freightliner and you'll be grateful.
 

Mike

Well-Known Member
It’s a simple process to put a manual start switch in. Put a switch into the Arctic sensor wire and bam. Manual override.

I have thought about that, but it's the principal. This should be on the controller. Between the delay of startup, and the long delay before the alternator begins charging (which is stupid), you put a huge draw on your batteries (things like a microwave or coffee pot) before the alternator finally starts picking up the slack.

the system is just majorly flawed, and honestly, I don't see them ever improving it. They made changes when they went to the evolution to try to increase efficiency, and I'm not sure they really improved things. Sure, I can go 2000 hours between maintenance intervals, but the rest really doesn't seem like an improvement over the old systems (which seemed to work better).

The 60/120 charging system needs to go away. A sense wire to the battery and a stronger alternator is what is needed. A better sealed case is needed due to where it sets. It's all doable, and would come with an increased price, but I would pay it.

Honestly, I think they simply see the writing on the wall. They have done all they are going to do with this system and transferred their focus to their e-APU and solar options.
 

mndriver

curmudgeon extraordinare
Honestly, I think they simply see the writing on the wall. They have done all they are going to do with this system and transferred their focus to their e-APU and solar options.
And e-APU and a solar system are just as expensive and heavy to get the same capacity and performance.

I can’t get enough reserve capacity in batteries with anything less than eight group 31 sized batteries for the e-APU alone. Then you still need no less than three for starting the truck.

Solar panels and the related hardware/wiring is no less than $6500 to get the capacity to recharge a storage system like that to enable you to utilize it for a 34-hour reset. Typical consumption for a microwave, computer and video usage, phone charging etc and running a refrigerator.

Toss in the replacement cost of batteries and the maintenance of a diesel sourced apu system, the tripac evolution still comes out money ahead in the total life operating cost.

It’s like you insist on this thing being a switch on the side of the bunk and function for over 10,000 hours with zero service concerns.
 

Mike

Well-Known Member
It’s like you insist on this thing being a switch on the side of the bunk and function for over 10,000 hours with zero service concerns.

Really?

The ability to hit a button for it to start from inside the cab would be a regression back to old units. It is stupid for a major draw on the system to take place for almost a minute while this thing goes through a start up process and eventual charging process.

10,000 hours? I would be happy with 4000 hours. 3 years of operation isn't too much to ask for, at least I don't think so.

The Evolution fails far more and far faster than the old units.
 

mndriver

curmudgeon extraordinare
The delay is a cold start up to let the engine settle. Mine was 8 seconds on the legacy unit and I haven’t messed with it for the evolution.

Again…it’s a software setting you can change if you just plug in.

My evolution has given me a fraction of the fits my legacy unit did. Most are attributed to faulty wiring that was over 10 years old.
 

Mike

Well-Known Member
Getting this taken care of today. Sounds like the alternator will only be a 1 year warranty, only major components are covered two years.

Also, it appears I use the APU much more with this truck than I did with the T660. 2200 hours in 14 months. With the T660, never topped 1400 hours in a year. Not sure how much more run time is attributed to the startup being at 12.5 volts, rather than 12.2 volts.
 

mndriver

curmudgeon extraordinare
I’ll hook up to mine and let you know my settings.

I want to say I dropped it to 12.2.

I’m barely at 1100 hours since 5/21 when it was last serviced
 

mhyn

Well-Known Member
i did little modification in Tripac and looks like this will give me more lifetime of alternator. i cut that tensioner bar about 2 inches and drilled new hole for bolt. Now the alternator is in the middle of muffler and engine. It stays cooler.. about 20F summertime..
 

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