TriPac Apu

Speaking of heaters, My former truck had an Tripac Evolution with a Espar Bunk Heater. The heater used to draw amps from the batteries and the APU would cycle on and off to keep the batteries charged. As for keeping the engine pre-heated in very low temps up north it seems the APU might run more that normal under certain conditions.

 

The coolant temp switch for the Arctic package is normally open. It closes when the coolant temperature hits 30 degrees and tells the APU to run.. It opens back up at 55 degrees.

If anyone wants a copy of the diagnostic manual for the older Tripac APU's, PM your email address and I'll send you a copy.

 

How much time are you giving the APU before you manually turn it off?
In cold weather, mine will run for the better part of an hour, maybe more before shutting down.

 

You're about right. But what's the definition of 'cold'?

Like I stated before, when it gets down to -10F, mine doesn't shut down anymore.

 

Well, at that temp, the water temperature running through the lines, to the block, and back to the APU may never reach a high enough temp to trigger the shutdown. That might be OK.

 

The temp switch closes at 30° to signal the unit to start. Once it hits 55° it opens to shut the apu off.

Disconnect one wire at the temp switch (doesn't matter which one) and see if it shuts off. If it does, it's a sticking temp switch. It's the one with white wires, not blue.

TA

 

And now you jinxed me... gotta look into why mine won't shut off today.