Dealing with AC issues after replacing just about every component (1 Viewer)

Joined
Dec 14, 2019
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328
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Texas
After replacing 90% of my AC, professionally, I'm now having issues. It's either freezing cold until I get it to 78 then it's hot (I've noticed the lever in the engine bay doesn't move at all until I get it to that 78 degree mark) and the next thing is if I have it on the low fan speed and I'm going 30mph+ it's like I'm getting all that wind from the outside inside the cabin (as if there's no wind blocker from the outside). It also seems like the AC works better, as far as temperature ranges go, below 30mph. I've searched and searched for weeks with no luck. Help a brother out I'm sick of ripping out my hair on this issue
Update 2:
Just an update after driving it. Started it in circulation mode at 76 degrees and low and drove it to 60mph and all was good. No extra wind, temperatures didn't get colder but it still was obviously cooler than 76. Then I switched it to Auto. It stayed at that temp until I hit 60mph then I heard a click and it got really cold and noticed that it was doing that outside wind speed again. I still need to look behind the glove box and control panel to see if there are any loose/unplugged wires

Update 1:
1) I have it on recirculate and it still brings in unregulated wind.
2) I had it replaced because my condenser died on me. Before this happened it worked perfectly. A Lexus technician did it.
3) Parts list.

Discharge hose
Suction hose
Denso Compressor
Denso Condensor
Denso Evaporator Core
Expansion Valve
Denso Dryer
Four Seasons O-ring kit
Refrigerent Oil
 
Last edited:
Joined
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Messages
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Location
Texas
did you also replace the expansion valve and the pressure switch? those were my issues.
Awesome! I replaced the expansion valve, but I'm not sure about the pressure switch. Hopefully I didn't so that I can be done with this.
 

alia176

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Sounds like the evap was dealt with so you're GTG from that aspect. The trinary pressure switch maybe fine so do the test per FSM before spending silly money on it. Is your condenser clean?
 
Joined
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Texas
Sounds like the evap was dealt with so you're GTG from that aspect. The trinary pressure switch maybe fine so do the test per FSM before spending silly money on it. Is your condenser clean?
Thanks for the heads up. I'll research how to test the pressure switch and how to check if the condenser is clean but I would hope it is because I bought a brand new.
 

flintknapper

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Make a list of the items that have been replaced and post it here.

Be complete....no "I think it might have" or its that "little thingy by they radiator".

We need to KNOW what has been done and any previous history (reason you had the work done), who did the work and anything else you can think of. Simply stating that 90% of the system has been been replaced (which I doubt) isn't really helpful.

Check to see that you have the unit on 'recirculate' and NOT outside air to see if the 'wind' intrusion thing stops.

Do NOT replace the trinary switch without first confirming there is a problem with it. For one thing....you have to evacuate the system of refrigerant to do so. IF the compressor comes on when you first start the A/C then chances are good the trinary switch (pressure switch is working). IF you have doubts, you can jumper around it.

What I am trying to establish is:

1. What has been replaced and by whom.
2. Is the unit currently properly charged with refrigerant.
3. When was the last time the unit was working properly (if ever).

We need a starting point here.
 
Joined
Dec 14, 2019
Messages
328
Location
Texas
Make a list of the items that have been replaced and post it here.

Be complete....no "I think it might have" or its that "little thingy by they radiator".

We need to KNOW what has been done and any previous history (reason you had the work done), who did the work and anything else you can think of. Simply stating that 90% of the system has been been replaced (which I doubt) isn't really helpful.

Check to see that you have the unit on 'recirculate' and NOT outside air to see if the 'wind' intrusion thing stops.

Do NOT replace the trinary switch without first confirming there is a problem with it. For one thing....you have to evacuate the system of refrigerant to do so. IF the compressor comes on when you first start the A/C then chances are good the trinary switch (pressure switch is working). IF you have doubts, you can jumper around it.

What I am trying to establish is:

1. What has been replaced and by whom.
2. Is the unit currently properly charged with refrigerant.
3. When was the last time the unit was working properly (if ever).

We need a starting point here.
Good points. I have it on recirculate and it still brings in unregulated wind. I had it replaced because my condenser died on me. Before this happened it worked perfectly. A Lexus technician did it. Here's the list.

Discharge hose
Suction hose
Denso Compressor
Denso Condensor
Denso Evaporator Core
Expansion Valve
Denso Dryer
Four Seasons O-ring kit
Refrigerent Oil
 

flintknapper

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Deep East Texas
Good points. I have it on recirculate and it still brings in unregulated wind. I had it replaced because my condenser died on me. Before this happened it worked perfectly. A Lexus technician did it. Here's the list.

Discharge hose
Suction hose
Denso Compressor
Denso Condensor
Denso Evaporator Core
Expansion Valve
Denso Dryer
Four Seasons O-ring kit
Refrigerent Oil

Excellent, that is very helpful.

It sounds to me like you had a 'compressor' failure (not condenser) and the tech replaced all the parts I would have replaced in that situation.

It is not stated whether or not the other 'hard lines' were flushed prior to the installation of the other components, but I certainly hope so.

At this juncture I'd like to see a set of manifold gauges hooked up and the High and Low side pressure readings....so we could be sure nothing is amiss there. IF those check out then I'd look to the thermistor on the new evaporator. Either it has become dislodged or is perhaps not working. Also investigate why the diverter is not blocking fresh air from entering the cab.

Thank you for the list, this helps. Please put the year model of your vehicle in your signature line so we know what we are dealing with in the future.
 
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Lafayette, CO
Pull the glove box and look for a disconnected or partially seated plug. Find out why the recirc isn't working first. It may lead you to the rest of the problem.
Pull the control panel from the dash and make sure things are still connected correctly there too.
 
Joined
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Messages
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Location
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Excellent, that is very helpful.

It sounds to me like you had a 'compressor' failure (not condenser) and the tech replaced all the parts I would have replaced in that situation.

It is not stated whether or not the other 'hard lines' were flushed prior to the installation of the other components, but I certainly hope so.

At this juncture I'd like to see a set of manifold gauges hooked up and the High and Low side pressure readings....so we could be sure nothing is amiss there. IF those check out then I'd look to the thermistor on the new evaporator. Either it has become dislodged or is perhaps not working. Also investigate why the diverter is not blocking fresh air from entering the cab.

Thank you for the list, this helps. Please put the year model of your vehicle in your signature line so we know what we are dealing with in the future.
Perfect. Thank you for your insight. This helps me tremendously. I'm gonna reach out to a local Land cruiser mechanic and I'll bring all of this to his attention. I wish I had all the tools to be able to do this myself so I could fix this over the weekend!
Pull the glove box and look for a disconnected or partially seated plug. Find out why the recirc isn't working first. It may lead you to the rest of the problem.
Pull the control panel from the dash and make sure things are still connected correctly there too.
Glad you brought this up. I'll check it out tomorrow as this is something I can do myself.
 
Joined
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Messages
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Texas
Just an update after driving it. Started it in circulation mode at 76 degrees and low and drove it to 60mph and all was good. No extra wind, temperatures didn't get colder but it still was obviously cooler than 76. Then I switched it to Auto. It stayed at that temp until I hit 60mph then I heard a click and it got really cold and noticed that it was doing that outside wind speed again. I still need to look behind the glove box and control panel to see if there are any loose/unplugged wires
 

flintknapper

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Joined
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Messages
9,726
Location
Deep East Texas
Just an update after driving it. Started it in circulation mode at 76 degrees and low and drove it to 60mph and all was good. No extra wind, temperatures didn't get colder but it still was obviously cooler than 76. Then I switched it to Auto. It stayed at that temp until I hit 60mph then I heard a click and it got really cold and noticed that it was doing that outside wind speed again. I still need to look behind the glove box and control panel to see if there are any loose/unplugged wires
Better look into it. By the end of this month or the 1st of May....it starts getting pretty hot here in Texas.
 

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