Howdy, Had a great time with my 328 on Sunday, drove it up to the lakes and it was about 80 outside, just a perfect day, and the weather here in the Northwest has been bad, so I was need for a drive ( or the car was in need....). The car ran PERFECT.. So a bit of history, last year when I had my belts done at the dealer, I had them check the charge on the ac and look for leaks, and they said it was fine, recharged it with R12, but the AC still did not work.... They said it was electrical. Last November, I contact Steve Magnusson via this web site, as he gave some other FC member some assistance, so I ask him for some input on my car. Of course the weather went bad, and AC was low on the priority list! Steve, and all you other Ferrari mechanics that help us out ..... Boy you are the best, your experience and your kindness to share with us is greatly appreciated....... Now the weather is nice, so I am going through the steps that Steve pointed out, and thought it might help others, and maybe get to the bottom of my problem with my AC. Here is where I am at: The steps that Steve gave me: 1. Try a different ...113 relay for relay P. - Switch it, and still nothing- 2. Remove the "w" connector (on the LH side of the fuse-relay panel) and inspect the second connector down from the top for thermal damage (it should have a large MN brown/black wire attached). If OK, plug it back in for the next tests (and, if fried -- repair it ). Turn the key "on", and measure the voltage on the MN wire relative to ground = should be +12V - OK, I may of done this wrong, I found a W type connector that feeds the blower, and had a brown/blackwire attached, and the voltage was 12V between ground and the wire. Not sure if I had the right connector.....- 3. If you pass test #2, remove relay 75c and measure the voltage from the female terminal 30 in the socket (it should have two VR green/red wires attached) to ground with the key "on" = should be +12V. This tests all of the upstream power components (fuse #17, relay P, connections) and the continuity of the blower motor itself (brushes, commutator, winding). - OK, checked it out and voltage is 12V at terminal 30- 4. If you pass test #3 (and with relay 75c still removed), measure the voltage from the female terminal 30 in the socket (should have two VR green/red wires attached) to female terminal 87 with the key "on" = should also be +12V. (There are two terminal 87 positions in the socket, but use the one that has a metal terminal in it.) This tests if terminal 87 has a good ground connection. -OK, checked it out and voltage is 12V at between terminal 30 and 87- 5. If you pass tests 3 and 4, touch a jumper wire from female terminal 30 in the socket to female terminal 87 in the socket = the AC blower fan should run full speed. - OK, put a jumper wire in between terminal 30 and 87, and fans run- So, I either missed the 'W' connector or need to move onto the next step. Let's see where we go from here...... Thanks so much. Bob
Thanks for the kind words Bob -- but I would've been happier if you had failed something in steps 1-5 as those are the easier fixes . Passing step 5 is a strong indication that something is wrong with the AC fan speed knob ECU (an expensive gizmo) or its associated wiring; Step 6: Measure the voltage between terminals 85 and 86 on relay 75c (while it is still plugged in) with the key "on": with the AC fan speed knob set below maximum = should be 0V with the AC fan speed knob set at maximum = should be 12V (but if it was, and relay 75c is OK, the blower should run at full speed just like when you use the jumper so I doubt that you'll pass this test) If you do fail Step 6, Step 7 would be to either swap one of the ventilation fan speed knob ECUs (items 24 or 39) with the AC fan speed knob ECU (item 100), or to do the voltage tests shown in the jpeg (and I forgot to add in the jpeg that with the key "on", the voltage between wire 1 and wire 2 should be 12V regardless of where the speed knob is set). Also check your item 100 for a small, plug-in 1A fuse that might be blown. Good (further) hunting! Image Unavailable, Please Login
Steve, So I thought it would be best to pull the console. Since I needed to do the flasher switch repair ( another great write up on this forum), since my switch turned on while I was driving last year. This is what I did, I switch the passenger heater fan switch with the ac fan switch. I plugged the passenger heater switch into the ac circuit and the ac fan worked, and I was able to slow the fan to variable speeds. So I then plugged the ac control unit to the passenger heater circuit, and it only turned on the fan when it was turned all the way up. Which I found strange? Must be a smaller load on the speed control. I did not see a fuse. Does this mean I need a new fan control switch or my passenger can't control there fan ;-( I assume these units can't be fixed? Let me know your thoughts, Bob
Just getting in and shaking/vibrating things a little can affect electrical gremlins. The architecture of the ECU+electrics+fan is such that variable speed and full speed are quasi-different modes, so often people report no variable speed, but full speed works OK. My recollection is that you initially reported nothing worked at any fan speed (but maybe that's wrong). The load on the ECU is really the same in both cases because the ECU closes a ...113 relay for full speed (rather than running the blower motor directly). If you swapped back and full fan speed didn't also work on the AC, I'd be very surprised (but the orig AC ECU could still have other problems because one of the other lines is also suppose to turn on the compressor clutch at any fan speed besides "off", and no variable speed isn't great). No fuse is OK. I know on TR, where they went thru 3 different fan speed ECU types, some of the early ones had the fuse while the last one didn't. I noted that the 328 SPC also showed an evolution of multiple fan speed ECUs so just wanted to warn you that it might be a possibility. Not really repairable IMO (even at ~$300 for a new one) unless you are a very skilled EE who works quickly . Pray you can get one -- about a year ago they were unobtanium (I sold the one I had to a F Dealer), but RA shows a price on their site so maybe that's a good sign that it's available again. PS With the swap, you've got the AC blower fan working correctly, but does the AC blow cold air (i.e., the compressor + refrigerant + etc. is all working too)?
Steve, OK, you are correct, that prior to swapping the connectors, the AC fan switch did not turn on the fans at all. When I switch to the passenger side fan switch to the AC circuit, the fans worked at all speeds. When I plugged the AC fan switch into the passenger side circuit, I can get the fan to run at full speed only. When I go back to the original set up, the AC fans do not come on at all. Now I have not tried to see if the AC actually blows cold yet, as I did all my testing at 1am in the garage, so I will start her up today and see if the ac blows cold. By the way, my local dealer had a fan switch on the shelf for under $200, so I went ahead and ordered it, since you mention they have been tough to find in the past, and all three fan controls are the same, I figured I would be covered. Thanks again, Bob
So, finally got the car running, since I left the dome light on when working on the car late in the evening and drained the battery a bit ;-( I plugged in the trickle charger, got her charged up, thinking I am going to start it up and have cold AC!!! But no luck. The inside fans came on, with the knob, but the AC compressor never engaged. I did try turning the temp knob to different positions, and nothing. I did check the connector by the oil dip stick, and looked at the radiator fan to see if it engaged, as I think I read something about the 308 or 328 radiator fan engages when the AC is on, I do have a few questions: Does the car have to get to a certain operating temp to have the AC work? Is the AC compressor like other cars, where the outer part of the pulley spins when the ac engages? Can I apply 12V to the connector by the dip stick to see if the compressor engages? So I solved one issue with the inside fan, but still need to move on to the next issue. Thanks, Bob
Hey Bob, did you ever get to the bottom of your 328?? Yes you can run 12v straight to your Comp. No engine temp needed. Stick a small drift into an A/C schrader to see if theres anything in the system first. Low pressure switch won't bother to turn on without 50lbs. And AMBIENT temp has a big factor, not engine temp. Curious what you did.. I just bought a 328 GTS. Going thru the whole car now. Oil leak, P- brake, CV boots yadyada.
