I started hearing a squeaking noise in the driver's side behind the left panel in the front footwell area...covered by a panel that holds one of the small speakers...also on the right passenger's side in the same area. I took off the panel covers and found that both blowers were running even tho I couldn't find any switch to activate them. They'd go on as soon as I turned on the ignition to the #1 or #2 positions, even before the car started.

I have a wiring schematic and looked for a switch somewhere and couldn't find one....both sides have a red 10 amp two blade fuse (doesn't show up in the schematics) which I ended up pullng out to stop the blowers. The blowers do increase in velocity when you turn on the top lever in the air control panel to the 1, 2 and 3 positons. I read the owner's manual (no help there) and all I can figure is that perhaps because this car is an 87...about the same time Ralph Nader was hollering about the danger of exhaust fumes seeping into a car....and that these blowers might have been added to keep running all the time to vent fresh air? The heater switches and mechanical levers all work, and the center dial between the seats also works for the heating cycles, but independently of the two front blowers in the side panels in the front footwells.

Does anyone else have these blowers running on low all the time and if so...where in the hell is the switch? I pulled every five pin relay in the front and rear panels to see if they would stop the blowers....but they didnt.

 

Chuck,
I have an '87 also and mine don't run all of the time. They will come on if the center console heater dial is any other position than off. I think '87 was a bastard year and a lot of the things that were on the '86 are on the '87s. Also some of the newer things on the '88 are on mine. If you want them off for good disconnect the harness plug going to each blower.

 

I think you're right....it seems that Porsche did some things sort of on-the-fly and changed little things here and there between the years....for instance, I cant find the fuse that protects the thermostatically controlled fan that blows air over the passenger rear fenderwell mounted oil cooler....yet there should be something there that protects the fan circuitry. Loren (RennTech) and I went thru the schematics and couldnt' trace some of the circuitry....but, if it works, don't fix it....I think by 88 and 89 they got things straightened out, but it almost seems that the 87 was sort of a rolling beta test platform.

 

Chuck, sounds as though are cars are different but, a reason that can happen is that the servo motor is not being able to fully return in the central control between the seats (the thermostatic unit). This can be due to the heater cables and flaps near the rear wheels.
May not be the reason but you could check it out to be sure.
The other possibility ha something to do with the rear fuse block in the left hand side of the engine compartment (behind the plastic cover). A short here can cause the motors to run so check the contacts of the fuses (change the fuses and give the contacts a good clean). I had to replace the fuseblock.
Again, may not be the reason but like the above it's something you could do yourself if you wanted to try.

 

Nathan: Now that you mentioned it, I just had some work done to the rear fuse box behind the plastic cover (but the US cars have them inside the left rear engine compartment). I had a problem with the fuel pumps running all the time even though there was no problem with the circuitry to the green plug below the throttle plate.....and it turned out to be a loose wire under the socket to the yellow relay in the rear circuit box.....which they fixed so that the fuel pumps don't run on when the ignition is turned on....but now since then the footwell motors have run...so you may have something there. I'll have to take a look at that fuse box and see if something is amiss there. The relay dial between the seats is working ok and only runs when the dial is turned up, and when I had the engine out, I got under there and cleaned up all those cables to the boxes. I do however have what sounds like a bushing going out in the forward blower motor behind the forward partition to the trunk....it periodically makes a loud squealing sound that definitely sounds like a dry bushing sometimes when you turn the dial..but only intermittently. This sounds like a good winter project...tear out all the motors and clean/lube them up.

 

Chuck,
I found this over on Pelican and it discuss your problem.
http://forums.pelicanparts.com/showthread.php?t=258473

 

Thank you Rudy....I went there and it looks like there's a good bit of info there that might help me track down the problem. One thing appears clear...cleaning and lubing the motors doesn't seem to be a permanent fix....the bushings seems to wear off after a while and the noise returns....may need new motors to permanently fix the noise problem.....but the wiring and running footwell motors info is great.

Thanks again for the referral.

 

Ooops, I mean't the left hand, sorry Chuck!

Oh, and my fresh air blower in the front has stopped working too.

 

Nathan: I saw a pair of footwell blowers on eBay by entering in Porsche 930 in the search window...both the right and left ones....looked damn near like NOS....I was going to bid, but decided to tear into the ones I've got first and see if I can either lube them up or maybe re-bush them. Hope you get yours workng right....I just pulled the fuses and let them sit doemant till it gets colder....like I said earlier....maybe a good winter job.

 

Maybe you should get them Chuck, I would think it is quite tricky to rebush them and greasing them may only last a year.
I didn't bother to mess with mine, I will just get a new motor. Hopefully I can remove the scroll without breaking it! I've read the trick is to use a hairdryer to soften it before pulling it off. If the scroll breaks I'll need a whole fan assembly $£$£$£$£$£.

 

mine squeaked on the middle speed setting too. i removed them, took them apart and cleaned them with electrical spray cleaner and compressed air.
then put them back together using some 20w-50 synthetic motor oil on the bushings and they are working good and quiet for almost a year now...

the bushings didn't seem terribly worn, just totally dry of oil and the motors were dusty after 20 years.

 

Actually, I have a motor for something else with those rose type phosphorous bronze busings that is used everyday. I simply sprayed WD40 in the bearings to lube and wash them out. It still works nearly a year later (touch wood)...