2013 LT air conditioner issues

[BertG]

I'm sure this has been covered.
I looked but I couldn't find the thread that I had found before.
2103 LT auto trans 35k miles.
Bought new.
A/C quits working.
Take it to the shop.
Starts off at $300, which went to $500, then to $700.
New everything...
Even a New fuse/ relay box.
Because the ac clutch wouldn't kick in unless the relay was twisted and a wadded piece of paper held it in a twisted spot, then the clutch stays engaged, and killed the battery.
I feel the mechanic threw parts at it, and the electrical issue has reared its ugly head. Repairs are at $850, the ac is "fixed". But its not.
With the new relay, fuse box, the clutch never egages.
So I put the old box back in, twisted relay and paper wad intack. AC works fine.
I'll tolerate disconnecting the battery over no ac. But it needs to be fixed.
My bride needs to drive it to work but I can't get her to disconect then reconnect the battery as needed while this issue is figured out. Mean while she's driving my truck, which gets half the mpg the car does. She's now driving 60 miles a day.

The ambient sensor is fine.
8 year old battery tested fine.
I want to replace it. Never heard of a battery lasting that long.
The altenator is only producing 12amps.
Never had any issues until now. 35k miles cream puff.
Any help would be appreciated.
TIA

 

[TZSKGB]

Had an ac issue as well earlier. To top that off the power steering wouldn't work and sometimes the car wouldn't start.

Replaced the battery and no issues since.

Had old battery tested and it tested fine 4/4 times.

 

[BertG]

Reinstalled the new relay/ fuse box.
Put a code reader, that shows everything the ecm is doing. The ecm quits telling the clutch relay to turn on.
Its intermittent. Sometimes the compressor will stay on for 45 seconds then sometimes its 15.
It might stay off for 30+ seconds before it kicks back on.
I've got a jumper wire on the relay to the neg pole of the battery and it stays on.
The only good thing is, is that when I turn off the key the relay is dead and the compressor clutch doesn't stay engaged, so I don't have to disconnect the battery.
In this south Alabama heat it works.
I need a permanent fix.
The dealer wants too much money.
Any ideas?

 

[TZSKGB]

Not a mechanic, so no clue. Seems like an ecm/ fuse box issue. Not sure how to diagnose that. Seems I got lucky with replacing my battery

 

[BertG]

The first thing after the ac replacement was the battery.

 

[Poobah47]

1) The temperature sensor a the evaporator may be defective. It's a cheap part, 10 bucks or so and easy to change. Its on the drivers side side panel to the center console. It's about 18" above the floor, above the gas pedal. 1/4 counterclockwise turn and out she comes. No tools required. It's a thermistor measuring the temperature out of the evaporator. it could be telling the HVAC control that it's too cold.

2) The pressure sensor is right at the compressor high pressure outlet, 3 wires coming off of it. Another cheap part, easy to change and you wont loose any refrigerant. This is the ONLY sensor on the refrigerant lines for monitoring pressure.

3) Let me know how it goes.