Test AC compressor

2014 v W/176k. Head gasket failed in April, replaced, then blew the #1 cylinder rod out both sides at the bottom of the engine 2 weeks later.

Dropped in a JDM engine and all was well for 2 weeks, but kept getting a P0AA6 hybrid system error and i could not switch the power modes, or have cruise control, but my AC worked. Then, 2 weeks later, "poof" it worked one day going to lunch, then warm air ever since Like flipping a switch off.

Nobody could read the detail code until i did the mini VCI cable and software dance. I have code B1498. and the freeze frame data for the P0AA6 shows .3 volts on the shortwave highest value which i read somewhere is a dead short in the HV wiring.

I looked over the HV compressor cabling very carefully and did not see any knicks or damage. Now compressor will not even attempt to turn on. I still have refrigerant charge tho.
I unplugged the HV wire to the compressor and voila the hybrid error went away and my modes and cruise control work.

My assumption now is the compressor suffered a concussion when the previous engine grenaded, and it died a slow death over that 2 week period it did work.

I am assuming the compressor is bad but would like to further confirm to make sure I am not missing anything.

Are there any tests I can do to confirm?
Should any part of the HV wiring go to chassis ground on the compressor?
What do I look for with a DMM on the compressor?
Can Techstream command compressor on?

Thanks in advance!

 

Ok I asked that question incorrectly, was in a hurry earlier, about to get away from work.

I know the HV wiring does not go to chassis ground in any way (that’s just dumb) but I think the old compressor is leaking ground to its HV wiring, giving me the hybrid system fault. It comes back immediately if I reset it. Unplug the HV cable and no error.

Is there an insulation test like can be done on regular AC motors to see if that is the real issue?

I am going to put a DMM on it this evening after we prepare for a lot of rain from Elsa tomorrow and see if I get readings from the compressor HV wiring to the compressor case in any way.

 

Thanks Chap - I thought about megging it, but only off the car. I don't want any chance of doing an insulation test like that to have any chance of frying something else in the process and making my situation worse. If I do it after the fact I will definitely report my findings here for future reference.

 

Well I'm pretty sure the compressor has given up the ghost.
DMM shows continuity on one side of its HV wire at infinity or no continuity, the other wire reads 1.89 ohms continuity.

 

Survived Elsa and had a bunch of boxes delivered today in anticipation of redoing my AC system this weekend. Everything fine except used compressor has a damaged 12V control connector. Like smashed to bits and pins bent over damaged.
Was like Christmas morning opening boxes and the main attraction gift was broken....contacted seller will see how it plays out but I am probably another week in this NC heat....

 

Nope...still sweating it out
I used a vac pump from Amazon, worked great. I vacuumed down to 29" and held there with manifold valves closed verifying no leak for an hour. Then I vacuumed pulled an additional 45 minutes. Then added refrigerant can added, purged line, and then opened low side manifold gauge slowly. It only sucked in a partial can and then just stopped.
I commanded the compressor speed with Techstream and still no dice. I was able to hear it changing speed but the data page shows zero RPM?
Its like something else in the system isn't letting refrigerant flow.
Its counter intuitive to everything I read and seen on recharging this system.
I've done successful AC work on other cars and my truck and I am very proficient with repairs.
Both gauges read 90 psi and vents blow warm..I have AC codes set that I can find, and doing the dash "auto" plus "recirc" at startup yielded a code 00 or basically nothing amiss.

I'm at my wits end...(almost)

 

Yep I am well aware of all these issues. When I swapped the engine, I cleaned the EGR and intake, was pretty nasty, and now i have a spare I can clean and swap. The AC connector looked pristine but I did put a small amount of dielectric grease on it to help ward off issues. I had to do same on my aging boat engine connectors.

 

Well FWIW I ended up going to a shop. The car had no codes anywhere, a clean slate. The tech was stumped at first but then went back for more tests and diagnosed the inverter not sending HV to the compressor. I think what happened was my original failed compressor backfed to my inverter and caused it to short somehow. Found used inverter locally and $500 later now I have AC back. Vent temps around 42 degrees.
I don't understand why the inverter being such a central piece of the hybrid system is not protected or fused somehow.
Hope this helps someone in the future.

 

Chap - That would be my 26' dual outboard boat. It is a never ending project lol!
It's sort of a hybrid too because I have a 100 watt solar panel on the top keeping the 4 battery banks topped off.
I appreciate all the responses and advice here.