veggiecar300

I am a brand new Porsche owner and just got a 1984 911 on Friday.
I just noticed something... The top of my AC compressor has four holes, but only three visible bolts. Am I missing one? Where would I go to replace something like that?

theiceman

your AC actually works ?

anyway I don't have AC, but if it is just a hole in a plate just take one of the other ones off and take it to a nut/bolt supplier and match up what you need.

veggiecar300

Well, now that you mention it, the AC doesn't work very well - or at least cold air does creep out, but the fan doesn't blow. Bad switch? Are these AC units notorious for not working properly?

theiceman

in a word yep ....

some of them can be made to work , but in the really warm climate they just cannot handle the heat , the ducting an stuff is just too small. Some guys have had success however and I am sure you will get lots of info here.

veggiecar300

I feel like there is at least a little bit of cool air coming out of the vents, but no fan. Is there a way to test the switch?

Here is a picture of the compressor. Missing bolt at the top right, or is it supposed to be like that?


Also, here is another picture. The bolt at the lower right of the compressor looks kind of funny - too long?

Chuck Jones

I actually have a factory AC unit that blows COLD air! When I first got it I found that it blew cool, but not cold air...so I had it charged up over a year ago and it's still blowing cold. This seems to be an anomaly for these cars. The AC units were put in to satisfy the US market...but apparently weren't designed for longevity or reliability.


Veggiecar: Since mine is a fully functional unit...I just went out and looked at it and compared it to your picutres...and there is NO bolt in that upper right hole...and that long bolt in the second picture is the exact same as mine....so it looks like you're good to go.

veggiecar300

Cool, thanks. Now I just need to see if I can test the fan switch somehow.

Mike Murphy

Congrats on your purchase and welcome to Rennlist. This is a great place to hang out...

I went to Fry's electronics and bought a $20 test meter. This has been the best and cheapest purchase for my 88 Targa. With the meter, you can check for 12V at the switch. My gut feeling is that your blower motor is shot, not the switch, but you have to test anyway.

The other test you could do is put the meter on the motor and check for 12V if that is easier to get to.

Mike Murphy

If I am not mistaken, your car also has a front condenser with a fan. Once you get the other fan working, you might test this one out as well.

nyne11

You are not missing any bolts. Here is your answer. Note on the bracket there are only 3 compressor mounting points even though there are 4 mounting holes on the compressor. Thes compressors are nipondenso and I suspect are used on other vehicles as well.

kplackmeyer

The funny looking long bolt is used to adjust the belt tension for the AC compressor. Loosen the bolts over the slotted holes, loosen the nut at the base of the long bolt, then tighten or loosen the long bolt until proper belt tension is achieved. Then re-tighten the set nut and mounting bolts.

veggiecar300

Thanks for the thurough answer!
Murphyslaw: I don't know about a front condenser. It is blowing sorta cool air from the front vents. Where would I find this condenser? Is it in the trunk somewhere? The only one I noticed so far was the one over the grille in the back. (the whaletail seems to be an add-on (?))
Sorry about the newbie questions.

Mike Murphy

I think the front condenser was added for the Carrera in 84. If you have one, it's located in the trunk and looks like a horn. That's the fan for it. It will be black, located toward the front of the car, near the jack, attached to the front bumper. It's job is to remove any heat that the rear engine compartment condenser cant handle. Thus, there is a motor in there. You can probably find the actual condenser if you look under the front bumper. It looks like a radiator.

The Whaletail is a Porsche option, and if you look up the option codes, it should show if it came with it or not.

veggiecar300

Yes! It's there.
So, is that front condenser controlled by the levers on the dash for the defrost? Or is it wired into the same two controls down by the shifter?

Mike Murphy

There are 3 separate climate control systems on the car. The AC is separate from the fresh air system is separate from the heating system. The only thing the levers do is direct heat up or down or direct fresh air up or down. So that AC condenser fan only comes on when the AC compressor turns on with AC switches.

It's all very confusing If you do a search, you should find a bunch of descriptions, discussion and even diagrams on it.