AC Troubleshooting - JDM FJ80

[zoojp]

1990 JDM FJ80 - 3FE. Has front and rear AC along with a cooler center console. 63,000 KMs.

So I filled (using COLD12, an R290/R600 blend - I'm not going to attempt to buy R12 in Japan) my AC two months ago and it leaked out within a week. I went ahead and ordered O-rings, a drier and expansion valve. I replaced all of the O-rings and the compressor ring. When I had the evaporator out, it had oil on the bottom of it, so I went ahead and replaced it as well. I did a visual inspection of the evaporator, the center console cooler evaporator and the rear evaporator. No oil present; though that doesn't mean they aren't leaking. I filled it back up and it worked well for a week. After two weeks, the low side pressure went from 50 psi to 10 psi at 70* (I followed the COLD12 instructions for amount needed to fill my system). The front and rear AC now blows cool, not cold.

While driving yesterday with the front AC is on, the cooler's ice maker tray frosted over even though the switch for it is off. As far as I can tell, there isn't any type of valve that would turn off flow to the console's evaporator. There is an expansion valve. With the front AC on, the compressor is running. I am assuming the center console is getting cold because gas is running through it.

My question is, if the system is at 10 psi and the front and rear AC aren't blowing cold, why is the console cooler frosting over?? I am guessing that there is enough gas in the system to make that small evaporator cold? Could this be a bad expansion valve on the cooler be causing this?

Does anyone else with a center console cooler know if it should be cold when the switch is off but the front AC is on?

I suspect my original compressor might be leaking. It has some oil on it. Next step as of now is to rebuild it (new seals) or replace it.

 

[ZeGerman]

When the switch is off in the center console cooler nothing should be happening in there regardless of AC running or not.

 

[zoojp]

When the switch is off in the center console cooler nothing should be happening in there regardless of AC running or not.

That's what I thought...so I think there might be an electronic valve, not the expansion valve, that will shut off flow to the center console if it isn't on...

 

[toyotaboy80]

Have you vacuumed the system? That is a very important step in replacing components. It 1) removes moisture from the system after being opened(primarily moisture from the dryer) and 2) it will tell you whether or not the system is sealed.

Moisture in the system can cause icing up... generally at the expansion valve. Low refrigerant will cause icing up... generally at the evaporator.

 

[zoojp]

Have you vacuumed the system? That is a very important step in replacing components. It 1) removes moisture from the system after being opened(primarily moisture from the dryer) and 2) it will tell you whether or not the system is sealed.

Moisture in the system can cause icing up... generally at the expansion valve. Low refrigerant will cause icing up... generally at the evaporator.

I did not...I don't have a vacuum and really didn't want to buy one.

But, if low refrigerant will cause icing up, that means I still have a leak. It still doesn't answer why the center console would be cold without the switch being on.

 

[mct75]

There are magnetic reed valves that control the flow of refrigerant, maybe one of those is stuck?

 

[zoojp]

Do US 80's have this valve? It is in line to the front AC evaporator.

 

[Tapage]

Do US 80's have this valve? It is in line to the front AC evaporator.

View attachment 1508658

I don't think they have it since it controls the flow to the center console ( fridge ) and rear unit when activated or not ..

 

[zoojp]

I don't think they have it since it controls the flow to the center console ( fridge ) and rear unit when activated or not ..

It controls flow to the front ac unit, not the rear or the console. But, it may be used to keep the flow from going into the front unit when the console fridge is on.

 

[zoojp]

I went out and took the console apart. There is no valve that will shut off the flow to the center console. It seems as if the front AC is on, the console is going to have gas flowing through it. But the console still has an AC amp, thermistor, expansion valve and cool/ice/off switch. I wish I had a JDM wiring manual and could read Japanese.

How is the flow supposed to shut off at the console if it isn't in either cool or ice mode??

 

[Tapage]

It controls flow to the front ac unit, not the rear or the console. But, it may be used to keep the flow from going into the front unit when the console fridge is on.

How is the flow supposed to shut off at the console if it isn't in either cool or ice mode??

I think your answer rely on my statement you said it's wrong ..

 

[zoojp]

I think your answer rely on my statement you said it's wrong ..

Sorry, I am not understanding what you are trying to say.

 

[zoojp]

Does anyone know if these fittings are AN sized?? I am trying to cap my rear lines but don't want to cut the lines.

 

[mudgudgeon]

Try searching for an Australian market EWD, or FSM
The Sahara version for the Australian market had the rear air and centre console fridge.

If you can't find a FSM or EWD here try on lcool.org/forum

 

[zoojp]

Try searching for an Australian market EWD, or FSM
The Sahara version for the Australian market had the rear air and centre console fridge.

If you can't find a FSM or EWD here try on lcool.org/forum

Good call. I found one and it doesn't seem to have any valve limiting flow to the center console cooler.

I am just going to cap the rear lines. Neither the cooler evaporator or the rear ac evaporator are available anyway. I think I'll be alright with just front ac.

 

[Twinair]

The evacuation procedure is a critical step in commissioning a refrigeration system. If you skipped this step then you wasted time, refrigerant, and the receiver/drier. I would recommend recovering the refrigerant, replace the receiver/drier, pressure test the system with nitrogen, evacuate system assuming there are no leaks, and recharge system. Moisture and noncondensibles are a refrigeration systems worst nightmare. Moisture in the system will collect at the expansion valve and freeze, blocking refrigerant flow which will cause a low suction pressure.

 

[zoojp]

The evacuation procedure is a critical step in commissioning a refrigeration system. If you skipped this step then you wasted time, refrigerant, and the receiver/drier. I would recommend recovering the refrigerant, replace the receiver/drier, pressure test the system with nitrogen, evacuate system assuming there are no leaks, and recharge system. Moisture and noncondensibles are a refrigeration systems worst nightmare. Moisture in the system will collect at the expansion valve and freeze, blocking refrigerant flow which will cause a low suction pressure.

Yes, I know, I was trying to avoid buying a vacuum pump. No one here has one for me to borrow.

I am going to buy a pump, dryer, compressor rebuild kit (just seals), possibly condenser, and then cap the lines going to the rear. Once I have the new parts installed, then I will pull the vacuum to get the moisture out and let it sit to check for leaks. If no leaks, then I'll but more refrigerant in the system.

It will be a few weeks until all the parts arrive here...the good thing is it's already getting colder out so not having AC isn't a big deal.

 

[zoojp]

I grabbed a pile of AN fittings from work for a test fit. The smaller hose is an AN6 or 9/16-18 thread. The larger hose is an AN10 or 7/8-14 thread. So that answers my thread question. But, AN plugs are for a 37* fitting, not an o ring on a tube. So I need to find cheap fittings that will work since I am not cutting these lines. Or maybe I can use the AN cap with some type of insert to block off the lines to the rear A.C..

Pump, rebuild kit and another dryer are being shipped.

 

[zoojp]

Tore apart the compressor and found out rockauto's kit was the wrong one. So I put the compressor back together. Everything looked new in it. I then realized that one of my R134 adapters was leaking. So I fixed it, put it all back together with a new dryer, vacuumed it for an hour, let it sit for an hour, and filled it back up. I left the rear and the console hooked up. Cold air!! It works. Let's hope it doesn't leak!

 

[Cgall100]

Tore apart the compressor and found out rockauto's kit was the wrong one. So I put the compressor back together. Everything looked new in it. I then realized that one of my R134 adapters was leaking. So I fixed it, put it all back together with a new dryer, vacuumed it for an hour, let it sit for an hour, and filled it back up. I left the rear and the console hooked up. Cold air!! It works. Let's hope it doesn't leak!

Sorry to churn up an old thread, but running into similar AC trouble with a JDM FZJ with the dual unit + cooler box system. @zoojp what was the issue with the R134 fittings? I bet I bought the same compressor from Rock Auto. I've attempted to repair the system a few times now. Properly evacuated the system each time then put in a Denso compressor and drier, then replaced the evaporator and expansion valve, then the condenser. Filled with 1600g as instructed and 24hrs later system is empty. It held pressure under vacuum and no obvious signs of leaking under a black light but some dye is showing around the fittings and running down under the compressor.