A/C won't work after replacing idler pulley

[suprarx7nut]

Hey guys, I have a problem that is leaving me scratching my head.

So I got my A/C recharged with R-12 last summer. All was well until the idler pulley started to go bad. I took off the pulley and ran without the belt attached for about two months this winter.

I reinstalled a brand new idler pulley last month and ever since, the A/C has failed to turn on.

I hit the A/C button and I can hear a relay~ish type clicking in the engine bay near the compressor when the button is pressed on or off. I'm troubleshooting now and I just can't seem to figure out what could have gone wrong over the course of two months not using it.

-I have checked fuses.
-The engine does NOT idle up when the A/C button is pressed.

TSRM on magnetic clutch:

So according to this, the VSV for idle up must activate before the clutch kicks in...

So either my VSV does not work, my Dual Pressure switch is shot or I simply have lost pressure in the system and the pressure switch will not activate.

Is there any way to tell if the vsv is shot? I have been watching the compressor areas ever since I got it filled and there is zero evidence of leaking. Wouldn't I be able to tell if the refrigerant started to leak out?

Anyone with some expert advice? I'd love to track down any easy fixes before letting a mechanic I don't know touch my baby to do a manifold gauge test...

Thank you guys.

 

[jetjock]

Which VSV are you referring to? AC idle up on the MKIII is accomplished by the ECU via the AC amplifier. If you're hearing the AC compressor relay everything on the control side (AC amp, ect) is working. That leaves low pressure, bad AC fuse, heater CB or relay, wiring, compressor clutch ground, or the clutch itself. And if the clutch relay is working you should get idle up. Check for a code 51 with the key on, AC on, and diag block jumpered. Keep your foot off the gas when doing it. And make sure you're not mistaking the condenser fan relay for the clutch relay. If none of that pans out put the old pulley back on

 

[suprarx7nut]

Which VSV are you referring to? AC idle up on the MKIII is accomplished by the ECU via the AC amplifier. If you're hearing the AC compressor relay everything on the control side (AC amp, ect) is working. That leaves low pressure, bad AC fuse, heater CB or relay, wiring, compressor clutch ground, or the clutch itself. And if the clutch relay is working you should get idle up. Check for a code 51 with the key on, AC on, and diag block jumpered. Keep your foot off the gas when doing it. And make sure you're not mistaking the condenser fan relay for the clutch relay. If none of that pans out put the old pulley back on

Lol at the old pulley. Thanks for the response, jetjock.

No codes at all. All fuses are good.

I was referring to the VSV in step 6 of the img above from the TSRM. It says VSV ON-----> E/G - Idle up. :dunno: That led me to believe the idle up was actuated by a vsv...

I had a friend click on and off the a/c and I can hear/feel the relay clicking and it is one underneath the fuse box, towards the center, passenger side of the bay, but directly underneath the fuse box.

Which relay is that?

Again, thanks for the help.

 

[mkiii222]

<- subscribed for what sounds like exactly the same problem (can hear a click from a relay in that area, but no idle up or A/C)

 

[jetjock]

The VSV reference is a mistake in the TSRM. Note none is shown in the diagram. Not that you should be using that crappy "schematic" for troubleshooting anyway.

When you say no codes do you mean in general or no code 51 when doing as I asked? You have to work with me guy. This is one time you want to see a 51 but you have to be in diag mode with the AC on and the throttle closed.

The condenser fan relay is also under the fuse box and looks much the same. However, it typically does not come on with the AC so you're probably OK there.

You may have an open low pressure cutout due to low charge. You can try jumpering the dual pressure switch in the liquid line on the passenger side fender. If the clutch comes on you'll need to put gages on the system.

Btw there's no need to run the engine when messing with the AC clutch circuit. All that's needed is for the key and AC to be on...

 

[mkiii222]

No code 51 here.

Just checked at lunch so couldn't jumper the pressure switch, but I'm getting the feeling it could use a new hose.

 

[mkiii222]

Decided to take mine to a pro Sat morning. (I'll mess with just about anything else, but A/C is something I feel should be left to a qualified tech)

As soon as he started giving it pressure the compressor started leaking in more than one spot.
So I'm going to replace the compressor and dryer now that I'm sure there's no R12 in there and take it back in to see if any hoses leak too.

Short version: Compressor + Dryer = $350, then any hoses that need to be fabbed and a topoff of R12.

 

[suprarx7nut]

The VSV reference is a mistake in the TSRM. Note none is shown in the diagram. Not that you should be using that crappy "schematic" for troubleshooting anyway.

When you say no codes do you mean in general or no code 51 when doing as I asked? You have to work with me guy. This is one time you want to see a 51 but you have to be in diag mode with the AC on and the throttle closed.

No codes present at all when jumpering diag terminals (E1 and TE1), with the A/C turned on before jumpering, foot off accelerator, throttle closed, key turned from off to on. The check engine light just flashes quickly to indicate no codes.

Why should I have a code 51 when doing this?

The condenser fan relay is also under the fuse box and looks much the same. However, it typically does not come on with the AC so you're probably OK there.

You may have an open low pressure cutout due to low charge. You can try jumpering the dual pressure switch in the liquid line on the passenger side fender. If the clutch comes on you'll need to put gages on the system.

Btw there's no need to run the engine when messing with the AC clutch circuit. All that's needed is for the key and AC to be on...

I checked the continuity of the dual pressure switch and it had no continuity with the key off or on. I then jumpered the switch's harness and the clutch sounded like it kicked on. (made a kinda deep click sound, i guess)

So it seems I need to have the pressure tested and see if I actually lost refrigerant...

If I did manage to lose refrigerant, should I have the place evacuate it and replace the seals, then refill it? Or if I am replacing the seals anyway, would it be smart to do a proper R134 swap and get the appropriate seals and a new dryer?

Thanks very much for your help JJ.

 

[NewWestSupras]

They won't refill R12 in Canada anymore, hopefully they are more liberal where you live. When I got mine retro'd, they had to replace seals, dryer, and a new expansion valve. I had already replaced the compressor, so all in all, it was a very painful upgrade. In the $800 neighbourhood. gl with yours.

 

[GrimJack]

R12 is still available south of the CAN/USA border. It's actually significantly cheaper to drive down there and get your system recharged.

A lot of the decision depends on what the problem is. If you've got a 15 year leak, just get it recharged and enjoy it for another 15 years. If it won't hold vacuum at all, you'll need to figure out where it's leaking and therefore what needs to be replaced. After you know this, it'll be easy to make the decision on R134a. Well, easier, anyway.

 

[jetjock]

It appears you're low on refrigerant alright and the low pressure cut out did it's job protecting the compressor. Odd you didn't get a 51 with the key and AC on with the block jumpered and the throttle closed. In that condition 51 is a good thing as it proves the AC signal from the climate control head is reaching the AC amplifier and TCCS. Since the clutch can't energize without that signal (even with the pressure switch bypassed) it must be working. Not that it matters as your problem lies with a low charge.

The decision to convert or not will have to be yours. As Grim says it depends on what it's going to take to make the system leak tight. If you do convert do it right. That means at minimum a flush, compressor oil change to POE or PAG, and HNBR O rings all around. No "death kit" from the car store. They work but will come back to bite you. I'm not saying you can't cheat (skip the O rings for example) but as someone who knows about this stuff I can only recommend doing it right. I'd stay with R12 but then again I'm licensed and have tons (well ok, maybe not tons) of it lying around. Replace the receiver/dryer no matter what you do...

 

[suprarx7nut]

First, let me take a second to say thanks JJ and Grim for the thoughtful and detailed input. I love this place.

It appears you're low on refrigerant alright and the low pressure cut out did it's job protecting the compressor. Odd you didn't get a 51 with the key and AC on with the block jumpered and the throttle closed. In that condition 51 is a good thing as it proves the AC signal from the climate control head is reaching the AC amplifier and TCCS. Siince the clutch can't energize without that signal (even with the pressure switch bypassed) it must be working. Not that it matters as your problem lies with a low charge.

[strike]You just made me realize something. I did my lighting modification while my A/C was down. Is it possible that I may have disrupted the A/C part of the CC unit somehow? The rest of the CC works just fine, though. Could my lack of a code 51 be an indication that something has gone awry within the CC unit or with its connection?

I think I might go out in the garage right now and pull out the unit and see if the [strike]continuities[/strike] voltages are as specified...

A pressure test on the system would also help determine this, I know.[/strike]

Nevermind, I just reread the bolded sentence.

The decision to convert or not will have to be yours. As Grim says it depends on what it's going to take to make the system leak tight. If you do convert do it right. That means at minimum a flush, compressor oil change to POE or PAG, and HNBR O rings all around. No "death kit" from the car store. They work but will come back to bite you. I'm not saying you can't cheat (skip the O rings for example) but as someone who knows about this stuff I can only recommend doing it right. I'd stay with R12 but then again I'm licensed and have tons (well ok, maybe not tons) of it lying around. Replace the receiver/dryer no matter what you do...

Trust me, if I want to try to retrofit it, I will be doing it right. I don't cheap out on anything related to the supra. If it's worth doing, it's worth doing well.

 

[tekdeus]

Is your new idler pulley super tight with no play? Mine rolls smoothly but has play when pushed sideways by hand. Also my A/C clutch is the same, rolls smoothly, yet seems to have a large amount of side play. What is normal for these pulleys?

 

[suprarx7nut]

Is your new idler pulley super tight with no play? Mine rolls smoothly but has play when pushed sideways by hand. Also my A/C clutch is the same, rolls smoothly, yet seems to have a large amount of side play. What is normal for these pulleys?

I dont recall any sideplay on mine. :dunno:

 

[jetjock]

There's normally a little side play but not very much. We're talking single row caged ball bearing here. It's very easy to change the idler bearing and not all that hard to change the one in the clutch. Course, if you have more money than skills you could just buy an entire new idler.

OP: Diag block jumped, key on, throttle closed, in P or N (if auto) and AC on should flash a 51. When I say AC on I mean the light has to be on in the CC button. That means a fan speed must also be selected or you must be in auto mode on the climate control. If the engine is off (it doesn't have to be running for the AC to "work") you should hear the clutch click on when you do this. In your case you won't because the low charge is keeping it off. You should still hear the clutch relay under the battery click though. Since it's close to the clutch it's been known to confuse people...

 

[mkiii222]

Update on mine: Reman Denso compressor + new Toyota(Denso?) dryer = ~$130 shipped. I'll swap those when they come in and then take it back to the shop and see what else is leaking. I figure on ~$300 worth of custom hose/freon/shop labor.

OP: It's probably better in the very long run to switch to 134. Many shops (at least here in FL Firestone/Goodyear/Sears and a few others I've talked to) are already not carrying R12 and it will only become more scarce. As for me, I'm taking that chance since there are several AC only shops and Toyota dealerships here in town that have tons of it.

 

[suprarx7nut]

There's normally a little side play but not very much. We're talking single row caged ball bearing here. It's very easy to change the idler bearing and not all that hard to change the one in the clutch. Course, if you have more money than skills you could just buy an entire new idler.

OP: Diag block jumped, key on, throttle closed, in P or N (if auto) and AC on should flash a 51. When I say AC on I mean the light has to be on in the CC button. That means a fan speed must also be selected or you must be in auto mode on the climate control. If the engine is off (it doesn't have to be running for the AC to "work") you should hear the clutch click on when you do this. In your case you won't because the low charge is keeping it off. You should still hear the clutch relay under the battery click though. Since it's close to the clutch it's been known to confuse people...

Ok, ya I was doing all of the above. I must be low...

Update on mine: Reman Denso compressor + new Toyota(Denso?) dryer = ~$130 shipped. I'll swap those when they come in and then take it back to the shop and see what else is leaking. I figure on ~$300 worth of custom hose/freon/shop labor.

OP: It's probably better in the very long run to switch to 134. Many shops (at least here in FL Firestone/Goodyear/Sears and a few others I've talked to) are already not carrying R12 and it will only become more scarce. As for me, I'm taking that chance since there are several AC only shops and Toyota dealerships here in town that have tons of it.

That's pretty cheap for the compressor and dryer. I'll be sticking with R-12 if it is anywhere near as much as the *proper* R-134 conversion. There are plenty of shops around here that still do r-12. When I called around last year asking about it the shops responded with "Uh... ya, of course we still do R-12" as if it was almost a silly question to be asking...