AC Issues - warm at idle, cold at speed (1 Viewer)

[TF88FJ62]

I've read a bunch of the "Warm AC" threads but haven't found my particular problem. Here are the basics: I have had my 88 FJ62 with about 140k miles four about 2 years (not my first summer with it). The PO converted it to R134 by an experienced shop but I do not know if with if any of the system components were changed in the process.

Problem: It blows warm at idle and the truck begins to overheat if i'm parked or in slow traffic. Until a couple months ago and last summer, the AC always blew cold. Once I hit 30-35 mph it is like a magic switch and it blows really cold. If i slow down, it gets warm and visa versa.

I am about to make it my daily driver and am in traffic daily. I recognize it is summer and particularly ungodly hot right now in the mid atlantic, but I am hoping there is a easy (and cheap) explanation. I also neither have the technical acumen nor tools to fix this myself. Any virtual diagnosis and guidance I can give my trusted shop would be appreciated. And yes, I have already thought about moving to a colder climate and/or away from traffic...getting rid of the truck is NOT an option.

 

[Landpimp]

Does it overheat if the AC is not on?
And is it really overheating? Or is the gauge just showing its getting hot?

A few things come to mind, assuming the AC is charged and not leaking.

Fan clutch, thermostat and possibly the AC amplifier(I dont think a 62 has the adjustment like a 60 does on the amp)

Of those the fan clutch would be my 1st guess. If it's not locking up(when it needs to) your cooling will be effected, which may also make the ac blow warm at idle.

$100 for a new aisan, pretty darn easy to replace.

 

[LAMBCRUSHER]

airflow is paramount...X2 on the FC; also check for general blockage of the condenser...

 

[TF88FJ62]

Does it overheat if the AC is not on?
And is it really overheating? Or is the gauge just showing its getting hot?

A few things come to mind, assuming the AC is charged and not leaking.

Fan clutch, thermostat and possibly the AC amplifier(I dont think a 62 has the adjustment like a 60 does on the amp)

Of those the fan clutch would be my 1st guess. If it's not locking up(when it needs to) your cooling will be effected, which may also make the ac blow warm at idle.

$100 for a new aisan, pretty darn easy to replace.

Good question on overheating. I experimented a little. The gauge climbed to halfway and then I turned off the AC and it dropped quickly. With the AC on, I also tried adding gas while in park and the temp gauge dropped and air cooled.

 

[dnp]

I agree with the others on the fan clutch. The symptoms directly reflect air flow. If it heated up without the a/c getting warm, it would be more indicative of radiator involvement. It also could be related to freon level. My 80 just started getting warm inside at idle, and when I vacuumed/added freon, that problem went away. However, with you experiencing both interior warmth and engine warmth, that points directly at air flow (also check for any debris in the condenser and radiator)

 

[2mountainfish]

X3 on air flow across the condenser and proper operation of the fan clutch.

 

[RockDoc]

Is your AC idle-up working? IIRC, idle should climb to 1000 rpm when AC is engaged to boost airflow, AC compressor output and alternator output. If it is indeed idling-up, x4 on checking you fan clutch.

 

[Landpimp]

It's a 62, so does not(or should not) have an idle up like a carbed 60

 

[TexasBlue]

Fan clutch by 4X...Reason for the AC idleup on 60 is airflow while at low speed/traffic. It is similar if your AC is set to fresh air it only works better when your moving.....good luck. Not hard to repair

 

[RockDoc]

It's a 62, so does not(or should not) have an idle up like a carbed 60

It's been a few years since I've had AC in my 62. I thought it did bump the idle, but I could be mis-remembering.

 

[Elbert]

fan shroud good, radiator fan in good shape and belts tight? I too would look at the fan clutch, or just get a new one if never replaced.

 

[LAMBCRUSHER]

It's a 62, so does not(or should not) have an idle up like a carbed 60

62s do too have idle up, just no adjuster pot on the amplifier board- that is handled by the ecu...my 62 idles static at temp at about 650; with ac on it goes to between 8 and 900...

 

[Landpimp]

Correct. But the idle up adjustment I was thinking of is on the front of the carb on a 60 along with the AC VSV. The little dial on the 60 amp is for when the ac kicks in(or something like that), but it won't adjust the idle or kick it up.

62s do too have idle up, just no adjuster pot on the amplifier board- that is handled by the ecu...my 62 idles static at temp at about 650; with ac on it goes to between 8 and 900...