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Seems they kept the same setup in the gen2s but you have to remove the engine or radiator to get access. No low pressure cutout switch or drying tank like the older units.

The system resembles those used in many aftermarket systems which used a temperature sensor located on the expansion valve (or controlled orifice) on the suction line where it enters the evaporator(s). A low refrigerant charge and lower than spec pressure on the suction line will cause external freezing and blockage of the evaporator coils preventing cooling so a temperature sensor will cut power to the compressor clutch and the electric radiator fans if the coolant temperature is within specs.

One would think ice forming on the evaporator coils is a good thing- it is not because at best it will cause frost and only temporarily block the coils to air flow - but the lower mass charge does not have the capacity to extract the mass of heat from the car interior so all you get is a rapid cycling effect that is insufficient to cool the air and extract heat from the mass within the interior. Compressor off, evaporator heats up, valve/coils unfreeze, compressor on, suction pressure rises, lines refreeze, compressor off.......xxxxx

Problem does not appear to be the high pressure cutout - if high pressure is above 400+ and the compressor cuts out and then cuts in again once the high pressure side drops.....it appears to be working in its role as a safety device.

Normal operation is that with the compressor off and allowed to sit for a while both low and high sides should equalize with the same pressure readings. Once in operation the suction (larger pipe) pressure lowers and the exhaust (smaller pipe) pressure rises. A low refrigerant charge will cause the low side to drop below pressure, freeze the coils (open the temps sensor) and cutout the compressor, but this will also cause a lower than spec exhaust (high pressure side).

Seems this is not what OP describes . i.e. a low charge, low pressure side but instead with a higher than spec high pressure side. Regardless of whether a system uses a low pressure cutout switch or a temperature monitoring switch, the high temperature switch should never be cycling the compressor and at 400+ p.s.i. this appears to be the case. So as mentioned previously the problem is likely air in the system which will cause the high side to skyrocket even if the low side is within specs.....with air comes humidity (moisture) and even if the volume of air alone only marginally boosts the high side pressure, the small traces of moisture (absent a dryer or a dryer which has become saturated) can be enough to internally block the small openings in the expansion valve or orifice and stop the flow of refrigerant while the compressor is constantly compressing what little refrigerant there is and pulling a partial vacuum on the suction side until the high pressure becomes so great the cutout kicks in.

My .02 At this point the system needs to be serviced by evacuation until the air is expelled and the moisture removed before refilling - continued addition of refrigerant while the high side is reading 400+ is simply not wise - should the high pressure cutout fail and you exceed test specs something has to give and either the compressor will fail, a line will rupture or a connection/fitting will blow at the under hood condenser or feeding the interior evaporators - and don't be anywhere near one when it does.

BTW - Oil filter is easy to change but there was a tradeoff- so here's where they buried the high pressure switch in the gen2s
Your picture of the hose I think is what was pissing green coolant. I also replied to this thread for a back story if you can offer any help.
 

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See my fan operation explanation in Post #4 here:


I'm hardly an AC expert. I'm fighting a somewhat different AC issue on my 2017 that I have yet to resolve. Hopefully someone smarter than I will respond to you also.

But if you've got a refrigerant leak (hissing?), you could try re-charging the system. You can get a can of R-134a at Walmart or any auto parts store. Here's a link to one Walmart sells (I liked this one because it came with the hose and gauge; you can then buy just the can without the hose if you need to do it again):


Hardest part is getting it on the fitting under the car. Here's a video:

 

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Okay not to make a long-winded response but I changed the engine temperature sensor and the fans eventually turned on but now that it's cooler out compared to the hot day that I was driving last week the car is running hotter than 210 so now I'm confused as to why the fans are coming on but the car is running probably 220 instead of 210? Anybody have any ideas because it's still overheating and it seems it got worse
 

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If it's running hotter than 210, I would EXPECT the fans to come on. If it's running hotter than 210, you may have a bad thermostat
 

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Did you use a GM sensor, aftermarket are very unreliable.
 

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I would have to check the part I used once everyone wakes up. I think the thermostat and pump are good. Might be the sensor. Nothing but issues the day I bought this car. Just weird how now, having the car for a few months it was always 210, now seems to be running higher then 210.
 

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I did not check the part I think it is an aftermarket part not a GM replaced it fans came on however the car is still overheating it gets to about 220 230 the fans kick on it goes down I replaced the engine temperature sensor and I'm thinking part of the issue is the heat protector that goes around that sensor might not be fully sealed like it's supposed to which might be causing the car to look like it's running hotter I know it's a long ways away but once I get my taxes I'm going to have the car looked at professionally any other ideas
 

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There's a possibility your fans are not running in low speed. See my Post #4 in this thread for the wiring diagram and explanation of operation. I'd check all 3 fuses (with a meter, not an eyeball). If they're good, I'd swap the 3 relays around and see if the condition changes. If it does, it's a relay.

 

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Been all over the web, I think my condenser is blown, I will check the fuses and relay. I'm off tomorrow. Did not check the fan speeds, but the passenger side fan blows off some really REALLY hot air compared to the driver side. That's the side where the inlets lead to the condenser, ideas??? I am going to buy that AC dye stuff and see if there is also a leak on that side to double check my theory.
 

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Everything you stated before had to do with the ENGINE cooling. All of a sudden you're talking about air conditioning.

Huh?
 
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