A/C control switch in F355

All I did was unscrew the access panel on the underside of the mirror and pulled the wires out a little bit to check them out. I didn't see the connection for the outside temp sensor.

 

Same prob here too. 97 Spider...defrost vents only. Sigh.

 

Same prob with my 97 Spider as well. YEP. Only from the defrost vents. I tried the battery reset with the vents selected. NO LUCK.

This is a VERY common problem.

HAS ANYONE FIGURED OUT WHAT TO DO????????

We all seem stuck with it being stuck, and that sucks.

 

I can say that since I updated this thread a couple of years ago, I've seen quite a few more 355s with this issue, and while the battery reset did cure a couple of them, by far the most common culprit is the vent diverter motor. Easy to check; only a couple of screws holds it on, so take it off and see whether the shaft moves when you adjust the air direction in the ECU. If it doesn't, it's that part.

 

THIS is the reason for everyone's issues...the trick is knowing how to get the system to recalibrate itself.

This is what we try when we run into this issue in our shop...

1. Turn off main battery switch.
2. Disconnect AC ECU
3. Make sure AC is on, setting 1,2,3,4, doesnt matter, make sure it is on and the "AC" button is pushed.
4. Reinstall AC ECU
5. Turn main battery switch back on
6. Turn the car to the run position without starting.
7. Dont touch anything, let it sit, it should cycle itself and you should be able to tell.


This obviously only applies if your hard parts check out good, flap actuator, AC ECU, etc.

*Disclaimer*

This isnt an exact way, its just what we do when we run into this issue, but it has been some time since we've seen one do this. It also may take a couple attempts.

 

The stepper motor is self calibrating /self setting /self limiting.

You should just completely install a "known good one", and I bet that will cure it

 

I tried to reset the ecu...ac on...set to 2 on the fan and the switch set to dash vents. No luck.

 

Wait. Now its blowing 10%out of the dash vents and still 90% out of the defrost vents. Hmmmm. Maybe it was always like this. I think so.

When i turn the knob...i hear no barrel movement at all. Nothing.

 

Also...i noticed my actuator door under the hood...well that used to be closed all the time...it has been permanently open for months now. What does that mean? So many questions about this enigmatic and slightly autistic ac system.

 

come on guys summer is coming. Any new information on this topic? Let's put our heads together and find a solution to this mystery

 

Been struggling with mine for 3 years without any resolution.

 

well I guess my next step is to go under the dash and pull out that little motor. Does anyone have any suggestions on how to do it?from the sounds of it it might just be a goose chase because people have tried to replace this motor and it did nothing

 

I've replaced motor under dash, ECU and motor for door actuator and still air only comes out of defroster. The motor will turn and then go back to its default position which is the defroster vent. I've given up and just have manually turned the diverter drum so it only comes out of the dash vents. I don't drive it in the winter so who needs a defroster?

 

I think this is my next step. How did you go about doing that? I understand these components are under the dash on the passenger side somewhere correct?the air conditioning is virtually useless when it comes out of the defrost it really is almost pointless

 

Take the motor out. Get a flat blade screw driver and insert into the slot motor goes into and turn until air is coming out of dash vents and you are finished.

 

I'm about to go out in the garage and attempt this.

 

okay so I crawled under there and took a look. I drew a green arrow to some electrical component that is screwed on to the evaporator unit. Is this what I am supposed to be replacing or removing?it's held on by two gold colored screws, one of which is nearly impossible to get to. I tried to look at the schematics and am not sure which item is the one that turns the barrel or whatever it is that redirects air toward the vents. when I turn the key forward in the ignition before starting the car I can hear something my spinning and spinning for about 30 seconds and then it just stops. it could be some other component but I am guessing that it is a little motor that turns the barrel....it might be stripped or something? does anyone have a picture of exactly what I am supposed to remove? Thank you in advance, -Brian
Image Unavailable, Please Login

 

Is this it? #12? "Timing Actuator?"
Image Unavailable, Please Login

 

I took the small motor out, which I believe is called the timing actuator, and rotated the barrel so it blows out of the vents. It still blows a tiny bit at the floor and at the defrost but I'm about 90% at the vents. huge difference and I didn't even have to spend any money. At this point I don't care much if I dont have defrost. I will finally have air conditioning when it's 90 degrees. that's good enough for right now. Summer is here I do, however, need a chiropractor. That was a brief, but painful job.
Image Unavailable, Please Login

 

it is a dirty job. I haven't given up on mine yet. I'm going to work on mine this weekend and see if I can get it to function properly. If not, I can live with it the way it is. I already have a bad back so not looking forward to it.

 

I always end up in that position under the dash, and at my age it is a painful experience. I am not that limber any more and actually got stuck once with a new fresh cramp in my right shoulder for 3 days ..... Shifting on back country roads fixed the shoulder.
These machines are actually therapeutic and I get more out of a full tank of gas than the copay at the shrink

 

Therapeutic is right.

If anyone is just at their wits-end with the AC coming from the defrost only, I suggest doing this. It took me about 15 minutes. 10 minutes of which was getting the top screw out, and 5 minutes was choosing what position I wanted to leave the barrel/diverter at.

GOOD TO KNOW: certain barrel positions will automatically flop right back to defrost. Keep turning it the opposite direction and you will find another position where it stays put on vents only. It seems spring-loaded in certain positions. Other positions it's not. Like I said, I am about 90% DASH VENTS, 5% FLOOR and 5% DEFROST. My passengers are often flip-flop wearing/ sun-dress wearing women who will enjoy the FLOOR vent a bit, haha. ALSO, the slight 5% at defrost will allow for a clear winshield, less condensation. The perfect mix, m'thinks.

Today I drive it and test, and hope that barrel stays put. I will post my results.

Lastly, I found that my motor DID NOT TURN when I took it out and started switching vent positions. Perhaps this is my culprit. Perhaps not. I don't care anymore, I WANT MY AC!!!!!!

-Brian

 

BOB, I have 2 herniated discs in my back, and once fractured my T8. Make sure you put your shoe on the door sill (where it says Ferrari). NOT putting your foot there will produce back pain. Take the bend off of your back by doing what I did in the photo, and put your foot there. A big help, seriously.

Of course I had my friend laughing when he took the impromptu photo, laughing, and saying "God, you really love this car"

Wear safety glasses too. Dropping a snub-nosed phillips-head in one's eye can ruin your day. Also, that insulation/rubber stuff flakes off and will fall DIRECTLY in your eyes, trust me. I did to me. But guess what? I FINALLY HAVE ADEQUATE A/C!!!!!

ALSO: wear a head-lamp....the one that straps to your head. Could not have done the job without it. AND, you need a telescoping mechanic's mirror to locate the top screw. You simply cannot see it without this and the headlamp. Or you could just do it blind, but that's not fun.

 

I've removed that motor several times so I know it can be difficult. Going to see if as someone suggested disconnecting the ECU and turning off the battery, and then reconnect everything with the A/C on and see if that helps. I've also pinched off the hose to the pump that adjusts the temp and now get really cold air and usually never have the fan on more that the 2 setting. Those valves in those pumps never seem to close completely and allow some hot water in and then the A/C won't be as cold. I don't use a heater anyway.

 

I am really wondering where that hose is, and where the ECU is located roughly. Any pointers?