2002 360 F1 A/C issue

I took my car to my A/C guy today because my car was blowing warm air when the A/C was on. We hooked it up to his A/C system and it was fine. It had the proper 750gms of fluid and it would make his gauges go up and down like they should when you bring the ideal up.

When I put the temp knob to 66 you can really feel a lot of heat, when I move it to the LO setting it is not as hot but it is vary warm still. The cooling guy thinks it's the flap that moves between hot and cold getting stuck. (hot/cool air mix motors)

Before I start investigating, I though I would ask you guys to see if you had any ideas.

I never used the air last year and this was the first time I put it on because we where going on a highway trip.

 

What your mechanic can do is up by the brake fluid access panel in front of the windshield by the drivers side there is the brake fluid reservoir on the right side.. and the heater valve on the left side. There is a connector there. That can be unplugged. There are 4 or so pins on the connector. The top two IIRC are the potentiometer that tells the computer the position of the valve. The bottom two IIRC (Red and Black) power the motor that opens and closes the valve. He can unplug it and apply voltage with a 9V battery to the terminals to test the motion of the valve. If its stuck open, or the computer can't sense the positioning.. this might be a place to start. Applying 9V red + to red +, black - to black -, in essence powering the motor closes the valve. (Alt: red to black, black to red OPENS the valve. If the venting is stuck.. that's beyond me.. I didn't think that there was a constant warm area in the HVAC.. but I'm going to research it now..

 

Is the "stop" button pushed in? If so, it kills the AC, but it will still blow hot air.

 

I was thinking the same thing -- confuses a lot of owners.
Alan

 

No, stop button is out. I can hear the compressor kick on and off when pushing the stop button in and out.

Curt, I will take a look at it tonight and do the 9v thing to see if the flap moves.

 

Hi Curt
Here is what I have so far. Looks like it was worked on before. I attached a some pictures. I think the gray plug is what you are talking about, but when I pull it off it looks like there are only 3 wires and one is dead. I did the 9v thing but nothing happened.

also one other clue, there is a hose that goes no where. it looks like it was attached to the bottom of the TGK Valve but I don't see anywhere the other side would attach to. I looked at a couple of diagrams and I don't have anything that looks like it would go there. My high pressure in and my out for filling the A/C is not in the same spot shown in the manual, they are next to the brake fluid res.
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

I have the exact same problem, had my 360 in for a front bumper respray and they managed to drain the battery by keeping the doors open. When I collected the car the
ac would only blow lukewarm air when the knob is at the lowest setting.
Have tried some reset methods with the battery switch but it did not work.
Some guy on the brittish clubscuderia site managed to get his working by reversing some
valve or flap with a battery.
Looking forward to hear more.

 

There is a procedure for resetting the heater after a battery disconnect, it might be worth a try.

360 heater only blowing cold air after dead battery - recalibration sequence

 

2mmuch, I think the grey plug is the charging plug for the optional battery charger/maintainer.

The wire into the TGK valve is what your're looking for. I've actually used this battery method to completely shut off the valve for summer operation. If you can find the wire going into the TGK valve.. that's the one. I'll bet its the one with the brown, blue, violet, orange, yellow lines going into it. Hmm.. I wonder if I have a pic somewhere.... It will be the female connector.

Odd that your charging port is up there..

 

Thanks Curt

I will pull that plug out and try it again tonight.

 

If I can jump onto this thread:

No AC in my '01 this summer. The high pressure line was replaced this past winter and I suspect they were not able to properly test it. I just want to do basic diagnostics. Maybe I can avoid the 2hr drive up to the shop.

My symptom is that the compressor only cycles for a second every 30 or so. I put a gauge on the low side and it's reading pretty high - 50psi. It dips down briefly when the compressor cycles.

I'll run through the reset procedure just for fun.

EDIT: following up on myself, the manual says low pressure should be 2.0 bar, where I'm seeing 3+. It also has a high pressure cutoff switch. Not knowing much about AC, could I just be seeing the results of an overfill?

 

The ecu is in the footwell on the drivers side on the heater box. Unplug it and plug it back in, they often loose position when the battery is disconnected then fail to work properly again..

 

Actually Luigi.. try what rustybits is recommending first.. could just be that.. very easy to do..

 

Just tried unplugging the ecu left it for about 5 min plugged it back in and started it up. Same thing. This time I stayed under the dash fired up the car and watched from under the dash as I rotated the dial from hi to lo and I can see an arm moving and I can hear the flap door open and close so I don't think the tgk valve is my issue. I can feel all the pipe under the dash and they are all vary hot. Not sure if any should be cooled.

Is 750gr the correct number of freion weight required which is just over a pound? or should it be higher and I don't have enough in the system.

 

I thought that flap door just directs the heat from the upper to lower areas on the dash... I thought the TGK valve is what regulates the heating in the system... ?

 

Looking at the tgk valve in the owners manual it looks like coolant goes through it and on my car the hoses to it are disconnected. That is the hose I am showing in the last picture. I will try the 9v on the tgk valve tomorrow and let you know what I find.

 

Hunh? INteresting! So you had heat in the car when you wanted to crank it in the winter? Did the monkey PO disconnect it when it got too hot in the past? See on page 7.38 of the owners manual how the line comes from the water pump, to the accessory electric pump, to the heater in the car to the tgk valve and then to the main water pump? Did they plug or disconnect a line?

Where does this line come from? Directly from the electric pump or back from the water pump?
and the line to the left of it.. does it go right to the main water line? Where do they go?
Image Unavailable, Please Login

 

So after knowing what the tgk valve does, I used vise grips and pinched one of the heater hoses and bang I had ice cold air coming out of my vents. So vrsurgeon you are correct with all your question. Why was the tgk valve by passed? Was it leaking? is it just not working and the past owner didn't want to spent the cash so just had it by passed to get heat for the winter? All good questions and I am about to find the answer. I am going to start by removing the tgk valve and testing it completely first, before I hook up any antifreeze hoses back on to it.

Thanks all for your help.

 

Probably cost. Its a few hundred dollars. If I have time I'll try to find an equivalent OEM..

Thank you for confirming I'm not going crazy.

 

Gents, just to jump in on this thread I've just had a similar problem with my A/C. The car is just back from service and I'm guessing they must have had the battery disconnected as when I turned the radio on it was asking for the code. I also noticed that I was only getting warm air blowing when the A/C was on. After reading this thread which has some really useful information I decided to have a look at the problem.
I first tried the heater reset which had no effect.
I then connect up a 9v supply to the proportional valve and motored it fully open and fully closed, still made no differance.
Tried disconnecting the A/C ECU, again no differance.
There were also two things that I discovered onlong the way and these were that when I felt the water supply pipes to the heater they were both hot, I'm guessing but must mean that warm water was passing through the heater matrix and the other thing I found was that the fan for the condenser/radiator was only cutting in when the when the engine required cooling, on all my other cars the fan runs when the A/C cuts in.
From the above I was wondering if the proportional valve was allowing water to pass into the heater matrix when it shouldn't.
Thinking that perhaps the valve wasn't fully closed I again connected up the 9v supply and I could here the valve actuate for a second or two, I'm guessing that this ment it wasn't in the fully closed position, I then reconnected the plug and put the ignition on, once again I then disconnected the plug and hooked up the 9v supply and again I could here the valve motor shut! it was almost like the output from the A/C ECU was driving the valve open slightly.
I then disconnected the A/C ECU again and using the 9v supply made sure the proportional valve was closed. I then hooked everything back up did a few more tests but the upshot was that now the valve seemed to be shut, almost like the ECU and the promotional valve were back in sync again.
Started the car and put the A/C on and low and behold lovely cold air. I also noticed that the water feed pipes to the heater matrix were no longer hot and that the condenser fan was now running every time the A/C kicked in.
So this seems to have worked for me, but I must say a big thanks to all the contributors too this thread especially Curt and Rustybits for without their contributions I would never have made any progress on this problem.

 

It seems I have the same problem will try this out, only one question what kind of 9v battery are you using? Can I use a ordinary Duracell 9volt?

 

Ordinary 9V. Reason I use 9V versus 12V is with a 9V battery you can move the motor and not have to worry about burning things out...

 

Did you perform this with the battery, main 12V connected or did you switch it of with the mains switch?

 

Did you at anytime turn off the main power or disconnected the 12V battery?

 

I just unplugged it and put 9V power to the TGK valve. With the key off there is no power to that circuit that comes off the AC ECU. I did not turn off the main power to the car.