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That was my thought as well.
 

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Discussion Starter #23
While the parts eper shows only one HVAC panel style for the 91-93 USA 164, maybe the B version doesn't have the auto option, as the others, L and S, have. If your car has it, it would be the left hand button, second row, in the HVAC panel.

I see that all the used panels for sale on eBay, etc, show an auto button, so don't know about any of the panels being from the B.

If the car has the auto mode, there should be an interior temperature sensor in the overhead panel above the windshield, ie, a little fan behind several air vent slots in the rear of the panel. Also, there should be a small temperature sensor either at the base of the windshield under the hood in the middle near the rear of the hood, or it may be a small bulb sticking out under the left hand outside driver's mirror.

Steve owned a B model, IIRC, so he would know for sure.

Maybe you will just have to buy a used panel. Easy to install.
As I am not the original owner of this Alfa, it is vary likely that the previous owner swapped his from a unit from Europe without the auto option. I'll look into it and see
 

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If you have a manually controlled system the control panel will look very different. Swapping between the two types of controls would have been very expensive.
 

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Discussion Starter #25
So I have been a complete idiot and missed the Auto button on the left side of the panel. That means I do have Auto and it is likely the original unit. However messing with the button didn't change anything and it is still refusing to respond to any input. Any clue where to go from here?
 

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If relay located under that tall square black plastic cover behind false fire wall near blower motor is your problem , you can rob one off the same type 50 Amp radiator cooling fan relays from top radiator support under middle plastic cover to test a/c blower motor.
 

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Discussion Starter #30
If relay located under that tall square black plastic cover behind false fire wall near blower motor is your problem , you can rob one off the same type 50 Amp radiator cooling fan relays from top radiator support under middle plastic cover to test a/c blower motor.
Yes I checked the relay and it's fine. However one of the wires going to that relay plug is very worn and exposed. It's a pink wire.
 

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pink goes to 86 (your low current control, or power input), not good is wire is exposed, as this is hot when HVAC switch is on. Did you swap in the relay from the radiator cooling fan as Steve says is the equivalent, to see if problem goes away?
 

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Discussion Starter #32
pink goes to 86 (your low current control, or power input), not good is wire is exposed, as this is hot when HVAC switch is on. Did you swap in the relay from the radiator cooling fan as Steve says is the equivalent, to see if problem goes away?
Yes I did and I also tried some newer relay spares I have from my Mercedes stash. Results were consistent
 

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I'm wondering if the EMCC relay (Q22) is the culprit, as it is linked to the blower relay via that pink wire. Steve Alfisto, where is the Q22 relay located?

emcc.jpg


q22_text.jpg
 

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Discussion Starter #34
I did some probing with the multi meter and here is what I found. There are three pink wires based one what you can see in the picture. Two thicker ones and one thin one. The thin as far as I can tell is the only one coming out of the dash directly. I want to know what that wire is exactly but it looks like its the one from the climate unit. It's constantly giving 12 v no matter what you do to the cliamte control unit. The thicker pink ones are pinched together into one plug. One leads to a plug that i believe powers the blower motor while the other comes out of another harness that leads somewhere underneath the blower housing. This plug gave a reading of 250mv there about. The red one is short and comes straight out of the false fire wall power distribution it seems and that one reads somewhere near the 250 mV as. The small black one is a ground.
 

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My, a lot of fragile wires there. The wiring diagram is hard to read when it comes to crimped wires, but if you have 3 pinks, it seems that one of them goes to a pin 1 of a 2-plug connection G165 somewhere in the engine compartment (it's called "Connector, door utilities to air conditioning wire"), another goes to the #30 of the Electro-Magnetic Coupling Control Relay (Q22), another to #86 of the same relay. I believe these wires are all normally hot when the ignition key is turned to RUN. Here is that page of the wiring diagram.
 

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G165 connector is under the dash and Q22 relay for A/C compressor clutch is behind the speedometer cluster. Q22 has nothing to do with blower motor. The smaller pink power wire is coming from 10A F12 fuse in G1 fuse box.. That SMALL pink wire IN G165 just sends power to pin 86 and pin 30 of Q22 behind speedo AND pin 86 of Q15 blower motor relay located next to blower

HOWEVER, the larger pink wire shown in his hand in picture goes to pin 1 short green wire of Q1 blower in the that gray 2-wire connector. That pink wire comes from pin 87 of the Q15 blower relay. It is powered when Econ or A/C buttons pushed on Q21a panel on dash. That larger pink wire also goes from pin 87 of Q15 relay to pin 1 of Q51 blower motor speed controller located in front of A/C evaporator box. There is a square 4-wire connector to Q51 speed controller that usually has degraded wire coatings, too.

Now longer larger green wire in gray 2-wire connector goes to short black blower motor wire and also goes back to gray-black wire going to Q21a on dash and also to pin 3 of Q51 speed controller. That large pink wire at blower motor gray connector should not have power unless Q15 relay is energized or coil or contacts stuck on. Removing Q15 relay from socket should stop blower motor.
 

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I'm beginning to think that the problem may the Q21a master control unit, as it's the unit that triggers the blower relay and also determines 0-1-2-3-4 fan speed, either automically or manually. You may be interested to know that one is currently up on ebay for $44 "buy it now", with "make offer" option. While it's a gamble it is certainly a gamble worth taking in my opinion.
 

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Discussion Starter #38
I'm beginning to think that the problem may the Q21a master control unit, as it's the unit that triggers the blower relay and also determines 0-1-2-3-4 fan speed, either automically or manually. You may be interested to know that one is currently up on ebay for $44 "buy it now", with "make offer" option. While it's a gamble it is certainly a gamble worth taking in my opinion.
I had been assuming that this would be the case the whole time, but wanted to single out other possible suspects. At this point it's worth just trying it and if it doesn't work ill just relist and get back to square one. Thank you guys for all the help. I'll report back with what I find.
 

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That is exactly what I have described earlier in my post. You will find that the entire HVAC wiring harness under the false firewall will have to be unwrapped and the bad wires replaced. I can already see you have the same problem most of these cars are now having. The insulation on three or four wires of the HVAC system are going to have very, very deteriorated insulation (bare wires!). No telling what wires are touching what wires and what havoc it will create, it will likely be different for each car, depending on what is touching what. I doubt very much there is a problem with anything else but the wires. Simple and cheap fix really, just get some wire on hand, electrical tape, and solder iron and just start unwrapping the electrical tape around the wires from the true firewall by the fan motor all the way over to the passenger side (where the switches are past the evaporator / filter housing) and replace the bad wires. It takes a few hours to do, but not too complicated. It will probably fix all your problems.
 

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You are going to have to remove the wiper assembly as well, to get to the beginning of the bad wires at the true firewall. That is the biggest pain of this operation. Use heat shrink tubing to cover your soldered splices. If you do not remove the wiper assembly you will not be able to accomplish this task for sure. You do not however, have to remove the fan motor housing.
 
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