Does 10 degrees make this much difference ?

[Tim Herald]

Yesterday it was low low to mid 70’s. Ran my AC and it was so cold I had to turn it up to about 40% of the blue/cold side. Today at 82 degrees, no matter where I set it, it barely felt cooler than just blowing the fan and no AC.

Will that change in ambient temp make that kind of difference, or did my AC crap out from yesterday to today ? Seems extreme???

 

[thatcabledude]

Yesterday it was low low to mid 70’s. Ran my AC and it was so cold I had to turn it up to about 40% of the blue/cold side. Today at 82 degrees, no matter where I set it, it barely felt cooler than just blowing the fan and no AC.

Will that change in ambient temp make that kind of difference, or did my AC crap out from yesterday to today ? Seems extreme???

Maybe something happened to your blend door operation.

 

[Tim Herald]

Maybe something happened to your blend door operation.

I hope it’s something simple like that. I figure the AC will struggle when it’s in the 90’s-but going up 8-10 degrees and low 80’s seems suspect for the system itself.

 

[CJF]

I hope it’s something simple like that. I figure the AC will struggle when it’s in the 90’s-but going up 8-10 degrees and low 80’s seems suspect for the system itself.

AC vent temps should be in the high 30s to low 40s regardless of ambient temp, except for possibly 100'+ and/or at idle. Stick an instant read thermometer in the dash vents to test.

 

[60 toy ota]

Have someone watch the control valve while you adjust the slider to make sure it's moving

 

[Tim Herald]

Have someone watch the control valve while you adjust the slider to make sure it's moving

I think it’s moving as it will go to melt your face hot, but I believe it’s not going all the way on the cold end and sticking at least partially open. Gonna have my son help me check when he comes by this evening.

 

[Tim Herald]

From what I see under the dash, the cable and lever seem to be moving where they need to but the cold isn’t kicking in like yesterday.

 

[Marvelicious]

What makes a bigger difference, at least to me, is UV. Mid 80s in the shade feels cooler than mid 70s in the sun. These 80 series cruisers are big greenhouses on wheels: they have a ton of glass. Most newer rigs have tint that blocks UV spectrum light more than it blocks visible light, but not so much our cruisers. I keep kicking around the idea of getting some of that basically clear UV blocking "tint" installed.

 

[Tim Herald]

What makes a bigger difference, at least to me, is UV. Mid 80s in the shade feels cooler than mid 70s in the sun. These 80 series cruisers are big greenhouses on wheels: they have a ton of glass. Most newer rigs have tint that blocks UV spectrum light more than it blocks visible light, but not so much our cruisers. I keep kicking around the idea of getting some of that basically clear UV blocking "tint" installed.

As I messed with it today - there is basically no difference on cold with AC off or on, so definitely a problem in the system somewhere. Not that it’s necessarily good UV stuff, but my truck is tinted all around except windshield. I have ruled out outside temp.

 

[ppc]

Yesterday it was low low to mid 70’s. Ran my AC and it was so cold I had to turn it up to about 40% of the blue/cold side. Today at 82 degrees, no matter where I set it, it barely felt cooler than just blowing the fan and no AC.

Will that change in ambient temp make that kind of difference, or did my AC crap out from yesterday to today ? Seems extreme???

Does the compressor cycle on and off?
I'm guessing that refrigerant has leaked out of the system.
Was yesterday the first usage of the year when was working? If so then good chance of an O-ring failure .

 

[Tim Herald]

Does the compressor cycle on and off?
I'm guessing that refrigerant has leaked out of the system.
Was yesterday the first usage of the year when was working? If so then good chance of an O-ring failure .

Compressor kicks on and had it off and in a lot lately and was at my local shop for 2 weeks a while back and they checked everything and said it didn’t need a recharge and were surprised how well it worked. They did clean up some wiring, replace a bunch of coolant and vacuum hoses etc. They spent time on HVAC - and again it has been working great and just switched overnight.

 

[Marvelicious]

Compressor kicks on and had it off and in a lot lately and was at my local shop for 2 weeks a while back and they checked everything and said it didn’t need a recharge and were surprised how well it worked. They did clean up some wiring, replace a bunch of coolant and vacuum hoses etc. They spent time on HVAC - and again it has been working great and just switched overnight.

That's quite a coincidence.

 

[LongDuck]

Just a thought; you mentioned it was blowing so cold that you needed to turn it to 40% hot to be comfortable. Does it normally sit on FULL cold at the temp slider inside the truck?

If yes, and this is the first time you've fiddled with the temp slider in awhile, open the hood and look at your Heater Flow Valve on the firewall. There's a flex cable that operates the valve open and closed, and sometimes it doesn't close completely - which would allow hot coolant to flow through the heater core, which your A/C would have to fight against. On the body of the valve is a metal fixture that both holds the cable (*poorly, using a weird clamp) and has a stop to prevent overtravel. Take a close look to be sure that with the slider on FULL cold, that the lever is completely on the stop.

Sometimes, moving the slider allows the janky clamp to loosen and then the cable comes loose enough to prevent the lever from going to full stop. You can loosen and reset the clamp with a flat blade screwdriver if you need to adjust it.

Have a look, as it's a 5 minute fix if that's the issue.

 

[Tim Herald]

Just a thought; you mentioned it was blowing so cold that you needed to turn it to 40% hot to be comfortable. Does it normally sit on FULL cold at the temp slider inside the truck?

If yes, and this is the first time you've fiddled with the temp slider in awhile, open the hood and look at your Heater Flow Valve on the firewall. There's a flex cable that operates the valve open and closed, and sometimes it doesn't close completely - which would allow hot coolant to flow through the heater core, which your A/C would have to fight against. On the body of the valve is a metal fixture that both holds the cable (*poorly, using a weird clamp) and has a stop to prevent overtravel. Take a close look to be sure that with the slider on FULL cold, that the lever is completely on the stop.

Sometimes, moving the slider allows the janky clamp to loosen and then the cable comes loose enough to prevent the lever from going to full stop. You can loosen and reset the clamp with a flat blade screwdriver if you need to adjust it.

Have a look, as it's a 5 minute fix if that's the issue.

Will do thx- but I have moved temp slider a lot lately as we have had wildly varying temps for weeks between teens and 80. So it’s been all over the place. Still worth a look as I feel like it’s something simple.

 

[CJF]

Will do thx- but I have moved temp slider a lot lately as we have had wildly varying temps for weeks between teens and 80. So it’s been all over the place. Still worth a look as I feel like it’s something simple.

If you want to keep guessing at simple things, watch the sight glass on top of the AC dryer and look for bubbles as the compressor cycles. (You're sure the compressor is cycling??) On a not too hot day, compressor should kick on/off every minute or two.

 

[ceylonfj40nut]

You said they replaced coolant. Why? Did they replace radiator? The 1fz-fe has temp switch that cuts off the AC compressor if the engine is above temp spec. Safety to provide more power for fan clutch cooling at the expense of AC. Had this issue when I replaced aluminum radiator with all brass (thinking it is more robust). Had the toughest time with AC. I went back to a Koyo radiator and have not had a AC issue since. Live in Texas.

 

[Tim Herald]

You said they replaced coolant. Why? Did they replace radiator? The 1fz-fe has temp switch that cuts off the AC compressor if the engine is above temp spec. Safety to provide more power for fan clutch cooling at the expense of AC. Had this issue when I replaced aluminum radiator with all brass (thinking it is more robust). Had the toughest time with AC. I went back to a Koyo radiator and have not had a AC issue since. Live in Texas.

Replaced coolant because I had a bunch of hoses replaced (badly needed and has some small leaks ) and thermostat, and it needed a general flush as part of baseline g. Temps seem to be just right. It all worked perfectly for about 10 days and then it just went to pot. I am hoping to get it back in shop to be checked as it’s over my head (doesn’t take much). Really need it fixed by next week as we had planned an outdoor/cabin weekend on the 3rd.

 

[Marco Lau]

1st of all, make sure your compressor is cycling on when the AC is selected. When the car is on idle, engage the AC will slightly raise the RPM from 6500 to around 6800-7000 rpm. If your AC button is pressed and your idle didn't change, your compressor is not cycling on. Also you can also pop the hood and look at the front of the compressor and the clutch should be engaged when the AC is on. w\When you mention the AC is not blowing cold, is your car moving at speed or are you sitting in traffic? The AC will cut off when your engine temp reaches +225F in an attempt to shed heat. The factory temp gauge sits in the middle between 155F - 225 ish so you might not be aware that your rig is overheating. Get an aftermarket temp gauge to get accurate coolant temp. if you have not already.

 

[Tim Herald]

1st of all, make sure your compressor is cycling on when the AC is selected. When the car is on idle, engage the AC will slightly raise the RPM from 6500 to around 6800-7000 rpm. If your AC button is pressed and your idle didn't change, your compressor is not cycling on. Also you can also pop the hood and look at the front of the compressor and the clutch should be engaged when the AC is on. w\When you mention the AC is not blowing cold, is your car moving at speed or are you sitting in traffic? The AC will cut off when your engine temp reaches +225F in an attempt to shed heat. The factory temp gauge sits in the middle between 155F - 225 ish so you might not be aware that your rig is overheating. Get an aftermarket temp gauge to get accurate coolant temp. if you have not already.

Compressor is kicking in. I have checked AC driving 45-55 mph as well as stop and go. No cold air blowing now. Again it worked just fine one day and the next day it totally went away. Nothing else I can tell so far has changed - idle,temp (for whatever I can see) etc. The aftermarket gauge is a good idea anyway.

 

[FJ80HI]

Compressor is kicking in. I have checked AC driving 45-55 mph as well as stop and go. No cold air blowing now. Again it worked just fine one day and the next day it totally went away. Nothing else I can tell so far has changed - idle,temp (for whatever I can see) etc. The aftermarket gauge is a good idea anyway.

I have a 92. Few years back my ac would work great then stop cooling. If it sat for a few hours it would cool again. Turned out to be a clogging expansion valve. Best thing to do is hook up gages to your high and low ports and find out what is going on. You can buy your own gages for under 100 and these have instructions and troubleshooting guide.