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A/C problems never fail - earnies2 - 06-16-2021
I thought I was being proactive this year. I have been out of work for almost a year and ½. Truck has been parked. So before I go out I went to check my A/C wich wasent that cold. The high side gauge was bouncing so I needed a compressor. I bought a compressor, receiver drier,expansion valve, high pressure fan switch and new thermosters. Vacuumed the system down put in 2.5 lbs R134 and new oil in the compressor. Nice and cold. Leave out to Chicago no problem took a load out of Chicago to Connecticut about ½ way there it starts blowing warm.. check pressure its fine start truck compressor kicks in its cold again ½hour later warm again... I have the switch mod for the BCM I flip the switch the A/C shuts off and goes through the differant vents but dosent blow cold. Whal going down the road I do a key flick and A/C starts working. ..so I'm thinking its the thermosters and I have a set with me I drain the system install the new thermosters gass it with 2½ cans and its working perfectly. Go figure new thermosters and one is no-good. That's a sucky system why coulnt they put a Schrader valve under the thermosters to make them easier to service.
RE: A/C problems never fail - Chamberpains - 06-16-2021
You may also want to replace any fuses, relays and breakers associated with the hvac system. It seems pretty universal to all truck now-a-days for these simple electrical components to tarnish or just not send current correctly causing all kinds of dumb problems like you described.
RE: A/C problems never fail - Waterloo - 06-16-2021
I bought one of these electronic ball valves off Amazon... https://www.amazon.com/gp/product/B06X9MHBCV/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I plugged it into the heater core coolant in line and ran the wires to the dash and installed on one of these on/off/on switches... https://www.amazon.com/gp/product/B012MYR82E/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
That ball valve replaced the manual factory valve under the hood. Now, when I want ice cold air, I flip the switch down and then off. This will shut off the coolant to the heater core. If I want warmer or hot air, flip switch up and then to off for heat.
This was the final piece to the puzzle in this lousy ProStar AC system. I installed this in May of 2019, still working, knock on wood.
RE: A/C problems never fail - W9L - 06-16-2021
I like the electric ball valve idea. One question,-doesit default to open or closed? Be nice on bunk and tank heaters too.
RE: A/C problems never fail - DVT873 - 06-16-2021
You might want to replace the belt and tensioner. Over time the tensioner loosens up letting the belt slip. Often this happens without any noise or squeal. Slippage makes heat. Heat changes the resistance in the clutch coil. The change in resistance changes the amperage the coil is drawing.
Just about all the OEM's today are monitoring that amperage. NAV in particular. If it goes out of a very narrow allowable range, hi or low, the body computer module (BCM) or electrical system controller (ESC) shuts off the compressor. This will set a code and maybe a light. When the coil cools down it resets. I think the key has to cycle. The code description is not real helpful. It will say something about over/under current. But nothing about cause.
I don't think it mentions any causes. Sorry, my AC memory chip is still sluggish. It's been cool here. Anyway most makes will do something like this with a body computer of some type and sometimes even an old school fuse.
Anyway best is to replace the belt and tensioner when a compressor is replaced.
The thermistors are a constant PIA. I check ohms before install. Both should have close to the same reading.
I think Rawze or somebody on here has come up with a schrader set up that allows these to be changed w/o draining the system.
RE: A/C problems never fail - Waterloo - 06-16-2021
(06-16-2021 )W9L Wrote: I like the electric ball valve idea. One question,-doesit default to open or closed? Be nice on bunk and tank heaters too.
No default, either open or closed. And to operate it properly, it will require the on/off/on switch according to the instructions that come with the ball valve. you simply switch to on for either function and immediately turn to off. It will cut the power to the valve motor if you forget to turn it off, so it is not going to burn anything up if you leave it powered on. It is not a selonoid, so no worries about it burning out on you if left on.
RE: A/C problems never fail - earnies2 - 07-01-2021
(06-16-2021 )Waterloo Wrote: I bought one of these electronic ball valves off Amazon... https://www.amazon.com/gp/product/B06X9MHBCV/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I plugged it into the heater core coolant in line and ran the wires to the dash and installed on one of these on/off/on switches... https://www.amazon.com/gp/product/B012MYR82E/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
That ball valve replaced the manual factory valve under the hood. Now, when I want ice cold air, I flip the switch down and then off. This will shut off the coolant to the heater core. If I want warmer or hot air, flip switch up and then to off for heat.
This was the final piece to the puzzle in this lousy ProStar AC system. I installed this in May of 2019, still working, knock on wood.
I
Been there done that I think when you originally posted it since then I replaced that valve with the stainless steel one and sealed the case better I git corrosion inside and it died
RE: A/C problems never fail - earnies2 - 07-01-2021
(06-16-2021 )DVT873 Wrote: You might want to replace the belt and tensioner. Over time the tensioner loosens up letting the belt slip. Often this happens without any noise or squeal. Slippage makes heat. Heat changes the resistance in the clutch coil. The change in resistance changes the amperage the coil is drawing.Do you have a post for the Schrader valve stup from Rawze
Just about all the OEM's today are monitoring that amperage. NAV in particular. If it goes out of a very narrow allowable range, hi or low, the body computer module (BCM) or electrical system controller (ESC) shuts off the compressor. This will set a code and maybe a light. When the coil cools down it resets. I think the key has to cycle. The code description is not real helpful. It will say something about over/under current. But nothing about cause.
I don't think it mentions any causes. Sorry, my AC memory chip is still sluggish. It's been cool here. Anyway most makes will do something like this with a body computer of some type and sometimes even an old school fuse.
Anyway best is to replace the belt and tensioner when a compressor is replaced.
The thermistors are a constant PIA. I check ohms before install. Both should have close to the same reading.
I think Rawze or somebody on here has come up with a schrader set up that allows these to be changed w/o draining the system.
RE: A/C problems never fail - smorgan87 - 07-02-2021
Snds like u need an arduino in ur life.