dead air conditioner

testshoot

testshoot

New member
Back a couple months ago my nearly new battery was dead so I connected a battery charger that has a 100A starter mode. The 2000 4Runner fired right up but it is as if I had lost power as my radio resets were gone and there was a burned wiring smell.

Everything seemed to work fine so I didn't think about it once the burned smell went away. That was the, now is now and now I don't have an A/C.

The fan works which it did in heat mode and it does in AC mode and the dash light in the climate control section shows AC is "on", but it is clearly not producing any cold air. One suspicion is the wiring to the compressor clutch is what was burned or some other wiring that affects the AC working.

It doesn't seem there is any fuses for the AC although I found a fuse which said AC but it wasn't burned out. Where would the wire be that goes from power to the compressor? I can't seem to find it.

Any other clues on what to check to see if it is an electrical problem which is my guess.

Thanks
 
Register to hide this ad
I would suggest they might be separate isolated issues. my AC needed a recharge when the previous owner first picked it up...
 
You can jump the pressure switch on the a/c line near the firewall if you want, just put a jumper in the connector for the switch, then if the compressor kicks in when you push the a/c button, (you should be able to see the inner part of the clutch actually turning) you know you just need a recharge.

P.S.

After you check, don't leave the jumper in or you may damage your system.
 
alanflies said:
You can jump the pressure switch on the a/c line near the firewall if you want, just put a jumper in the connector for the switch, then if the compressor kicks in when you push the a/c button, (you should be able to see the inner part of the clutch actually turning) you know you just need a recharge.

P.S.

After you check, don't leave the jumper in or you may damage your system.
Click to expand...

Of course, it could be empty and open to the air, in which case a recharge is useless and a waste of money. You might even damage something. It could be locked out due to overpressure, and a recharge would be the worst thing possible. Buy or borrow a set of gauges and really see what is going on there. With coupon, about $70 at Harbor Freight. Mine have paid for themselves several times. I went on to buy a leak detector and a vacuum pump. I maintain three older cars and these have been good investments.

There are some good DIY A/C forums where you can get help from people who understand these systems. It took a lot of reading, but I now feel educated on how to deal with them.
 
I have one of those A/C system rechargers and have kept it topped off. However if the compressor isn't working, you can't recharge the system, or at least I don't think you can.

Where is the pressure switch on the firewall? Can you describe it or tell me where it is. I don't think the compressor is attempting to turn but frankly, I haven't looked at it with the engine running.

Will check it but I doubt it is turning but I also doubt the system needs charging as I used the air a few months ago and topped it off less then 5-6 months ago.
 
"This is just the poorman's first step in troubleshooting your problem" All this will do is tell you if your suspected wiring problem is the culprit or not. If you have been having to keep it "topped off" then you are loosing refrigerant somewhere...It's probably low enough to keep the compressor out. If you don't have the aforementioned gauges, and you still want to do a quick check... On the line coming from the firewall, there is a round pressure sensor/switch with a two wire connector going to it. Start the vehicle, turn on the a/c, put a jumper in the wiring connector for that switch, note if the compressor turns or not. If it turns, your wiring and clutch are fine, if it doesn't, you may have let the smoke out of something, as you suspected.

Hope this is helpful...:cowboy:
 
Last edited:
Thanks to everyone for the suggestions and guidance on the problem. Let me tell you what I have found out:

1. the compressor is working...it cycles on and off properly it seems
2. the A/C lines are COLD....so the A/C is producing cold properly
3. still no cold air blowing through the vents

I should also mention something that seems connected. The A/C system has two modes, either recirculate cabin air or pull in fresh air through the cowl. That isn't working either. I get the same "warm/hot" air when I put the system in "fresh air" mode as I get when I put the system in air condition mode.

That seems to tell me that there is a flap that isn't opening or closing as the case may be. Not knowing how the air flows under the dash, it seems when you put the system in "fresh air" mode, I should get cool outside air which I am not, so the flap isn't positioning properly to get outside air. I don't know where the air is coming from as if I switch it to recirculate, the air is cooler than when choosing outside air, even though the outside air is 20 degrees cooler than the inside air, i.e. might be 50 outside and 75 in the vehicle but still the air coming out of the vents in outside air mode is not 50 degrees and is warmer than the air I get in recirculate mode.

When I smelled burnt electrical wiring, it could have been wiring or a solenoid, such as what might operate a flap.

Does anyone know what might be common to outside air model and air conditioning model as I am getting the same air in either case and what needs to flip or flop to get cold air isn't happening. I could use some assistance on whether there is a wire, fuse, or solenoid that could be the cause.

Thanks so much!
 
Do you have digital or manual control? If digital, the system has a self-diagnostic and reads out trouble codes on the temp display. If you do, I'll post the links for you or you can find it in the fSM.
 
The temp is displayed digitally but I haven't seen instructions on how to get the results to display. Could you please refer me to the instructions.

Thanks sir!
 
testshoot said:
The temp is displayed digitally but I haven't seen instructions on how to get the results to display. Could you please refer me to the instructions.

Thanks sir!
Click to expand...

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/acsy/preche.pdf

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/acsy/dtcc.pdf

Also useful:http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/acsy/pst.pdf

If you get a DTC, look up the detail here, under Diagnostics, Air Conditioning System:

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/local%20files/repair.html

Your symptoms could also be a blocked/bad expansion valve--a gauge set is needed to know for sure.
 
Thanks to your help, I was able to get two errors. The first one is confusing as I didn't know I had a solar sensor:

Solar sensor circuit (short) Solar sensor circuit (open)
Solar sensor
Harness or connector between solar sensor and A/C control assembly
A/C control assembly

The second error, 41, seems to be what I more or less figured out:

Air mix control servomotor
Air mix damper position sensor
Harness or connector between air mix damper servomotor and A/C control assembly
A/C control assembly

What that is telling me is that either the harness/wiring between the control and the servo is fried, or the servo itself is fried. That tells me I need to check the wiring between the control and the servo and check the servo itself.

Because the fresh air mode wasn't working and the A/C isn't blowing the cold air into the cabin, it seems obvious that there is a damper that isn't operating.

The link you gave me gives me a nice picture of the servo and then says:

Remove air mix control servomotor (See page AC-34)

When I use the repair documents you so nicely provided, I see instructions for an inlet servo, an outlet servo, but not a mix servo. In the diagnostics section there is inlet, outlet, and mix, but in the repair section it only refers to inlet and outlet, not mix?

Also, on the air inlet instructions, it says:

REMOVE GLOVE COMPARTMENT PARTS (See pageBO-69)

I wasn't able to find the glove box instructions either although I am hoping that step is obvious, but if there are instructions, that is cool to. I am making an assumption the mix servo is also behind the glove box.

Am I missing something.

Thanks so much for everything!
 
testshoot said:
Thanks to your help, I was able to get two errors. The first one is confusing as I didn't know I had a solar sensor:

Solar sensor circuit (short) Solar sensor circuit (open)
Solar sensor
Harness or connector between solar sensor and A/C control assembly
A/C control assembly

The second error, 41, seems to be what I more or less figured out:

Air mix control servomotor
Air mix damper position sensor
Harness or connector between air mix damper servomotor and A/C control assembly
A/C control assembly

What that is telling me is that either the harness/wiring between the control and the servo is fried, or the servo itself is fried. That tells me I need to check the wiring between the control and the servo and check the servo itself.

Because the fresh air mode wasn't working and the A/C isn't blowing the cold air into the cabin, it seems obvious that there is a damper that isn't operating.

The link you gave me gives me a nice picture of the servo and then says:

Remove air mix control servomotor (See page AC-34)

When I use the repair documents you so nicely provided, I see instructions for an inlet servo, an outlet servo, but not a mix servo. In the diagnostics section there is inlet, outlet, and mix, but in the repair section it only refers to inlet and outlet, not mix?

Also, on the air inlet instructions, it says:

REMOVE GLOVE COMPARTMENT PARTS (See pageBO-69)

I wasn't able to find the glove box instructions either although I am hoping that step is obvious, but if there are instructions, that is cool to. I am making an assumption the mix servo is also behind the glove box.

Am I missing something.

Thanks so much for everything!
Click to expand...

Here is BO-69 (under Body Mechanical in the last link I posted.)

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/bo/inspan/remo.pdf

I can't tell you any more about the mix servo as I have a manual control and I'm really not at all familiar with the digital system--I just saw the diagnostic mode in the manual. But a dead mix servo certainly seems to fit your symptoms. I believe these servos can sometimes be revived by extracting a plastic gear and turning it 180°. Search and ye shall find.
 
Thanks you kind sir....:high5:

They talk about removing the door and a trim part below it, but not the box itself...I am guessing the glove box itself might be obvious when I tackle the project. Sure is surprising that the list of repairs is missing the one I probably need....gosh darn...
 
I know this is an old thread, but I'm trying to diagnose my issue. I have the digital display. None of the links you posted work any more. Can you explain how to access that diagnostic screen?





TheDurk said:
Free Web Hosting - Your Website need to be migrated

Free Web Hosting - Your Website need to be migrated

Also useful:Free Web Hosting - Your Website need to be migrated

If you get a DTC, look up the detail here, under Diagnostics, Air Conditioning System:

Free Web Hosting - Your Website need to be migrated

Your symptoms could also be a blocked/bad expansion valve--a gauge set is needed to know for sure.
Click to expand...
 
You must log in or register to reply here.

Members online

Total: 233 (members: 1, guests: 232)

Forum statistics

Threads
278,306
Messages
3,554,045
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top