vtrich

My engine blower had been working fine, then, a few weeks ago quit working. For as long as I have owned the car,..about 3 years,... the front blower has not worked. Now, all of a sudden they both began working? I had been messing around up front to see what it would take to replace the front blower, so it's possible I did something,....but wonder if the two blowers are in any way connected. Oh, yeah, now, they are both not working again?

I've checked fuses and all look fine,...any ideas?

I guess I assumed they are completely separate, but really bizarre that in this case, they seem to be tied together somehow.

Rich

LaughaC

Might check the dash slider for bad connection.

3.2SLANTNOSE

As far as I know, the front blower should only operate when the A/C is turned on, and the engine compartment blower should only operate when the heater handles are lifted. It does sound like something is crossed somewhere.

vtrich

ahhh,..thanks slantnose,..this helps. I guess I figured the rear blower only operated with the levers raised,..still,...tomorrow,..I'm going to take out the felt trunk liner,...and mess around again,...see if I can somehow recreate whatever it was that got them working in the first place.

D.C.

There is lots of really good information here or over on Pelican, on how the heater blowers work, and why they dont work. "Mysterytrain" is the resident expert, and I fixed my heating, front and rear using information that Mysterytrain posted.

I do not believe that the blower in the trunk has anything to do with the heat. I think the blower in the trunk is related to fresh air flow.

Here are the electrical components related to the heat. I think this applies from 84 to 89.
Rear blower. (engine compartment)
Footwelll blowers. (in the footwells)
Blower relay. (engine compartment)
Fuses. (engine compartment)
Heater levers (must be up for blowers to operate)
Speed switch. (between seats, for non automatic heat)

You can test all the blower motors by directly running 12 volts to them. I think that these motors typically loose the bearings, which means that when they go bad, sometimes they run and sometimes they dont. Sometimes when they are bad but still running, they make really bad screetching noises.

I think I recall that if the rear blower is broken, that the footwell blowers will not work.

3.2SLANTNOSE

vtrich, when I stated that the blower up front should only be on when the A/C was turned on, I was talking about the front A/C condenser fan, I was not talking about the fresh air, dash area fan. The dash fan is controlled by the slide controls and fan speed controls, but it still would have to have something turned on to be working, or wires crossed. Good luck.

der Mond

My rear heater would not shut off and the culprit was the relay for it, which is located in the engine compartment to the left behind the black plastic cover just to the rear of the car from the fuel filter and coil. The cover should have one large wing-nut holding it in place. It is a rectangular silver relay and sits next to the one for the rear window defroster, if you have one. Give it a whack and see if it suddenly works. The fresh-air blower is separate and I'm going to go out on a limb and guess that perhaps both blower motors need to be replaced (if its not the relay) and it's coincidence that they happen at the same time. stranger coincidences have happened. I replaced both blowers on my former '87 at about 125K miles. The rear is simple but the front requires at least a Bentley manual and some patience, because it's not necessary to do exactly what the Bentley manual says to do, like remove the whole fresh-air screen assembly. If you do need a relay may I suggest dealing with the parts man at Hennessey Porsche in Atlanta, who gives excellent dealer discounts and will ship parcel post.

vtrich

THANKS derMond!

I haven't had time to mess around with either,...but tonight I'll check out the engine blower relay,...see if I can at least get that one working. Certainly possible that it's coincidecedental that they gave up together. The engine blower was consistently functioning all along,...so I'm thinking maybe they got together and are pissed at me for something.

Rich