Hi Everyone... Here is my issue. My AC/Heat controller head only turns on the fans once I turn it on the 4th speed. Did anyone ever experience this? Any ideas what it can be? The controller was replace this past summer NEW. Not even a year old.

Please advise and thanks for your help?

Alan

 

check the blower fuse . and relay
get a fuse relay chart here 928gt.com find page 2 click on tips and links print off a fuse relay chart and inspect the CE panel for the correct position and amp of the fuses.
also use a pencil eraser to clean the fuses

 

On my S4 I only had two fan speeds. I replaced the resistor pack, and that fixed it. You can get the pack from any of the sponsors.

 

It does sound most likely the blower speed resistor pack. Not all types are available new... depends on year.

For older cars where the pack is NLA you can subsitute a later resistor pack - however you need to change 2 connections in the plug that attaches to it to make these work.

What year is your car?

Search for "magic blower" and you will see many more threads on this issue - yours is beuond the 'magic' phase but same issue...

Alan

 

Thanks all for your responses. the car is a 1991 928 S4 - 68k miles. does anyone know the part number for the resistor pack and also where it would be located? is this something i can do myself?

 

The part # is 928.616.101.00. Roger @ 928RUS , 928Specialist or 928 International can help you. You might find this link helpful.
http://jenniskens.livedsl.nl/Technic...0/MyTip003.htm

 

you should check the fuse and relay , if they are good then remove the resistor pack and inspect it, you might find your problem without replacing any parts.
The resistor pack is under the hood under the black cowl cover in the center of the blower duct, you pull the big plug then put a rag under the screws then unscrew it use a coat hanger with a small hook on the end, to fish it out from the rubber bellows where the duct joins the blower motor

 

It is certainly something you could do yourself - the blower packs for your year are still available new.

See details in those other threads...

Alan

 

Thanks all, I will check the relay and fuse first. If needed, I will order the resistor pack. Since I will be in there already, anything else I should change? Mrmerlin mentions rubber - it sounds like there is a rubber gasket of some sort that the resistor sits on?

Also, looked at the fuse / relay diagram. Can someone confirm that the relay I am looking for is labeled XII and the fuse is position 20 and is a 30amp, position 37 and is a 7.5amp?

 

no the resistor pack sits on the side wall of the blower duct.

To get it you push the rubber connecting duct ( connects the blower motor to the blower duct) away from the plastic then reach inside the duct with a wire and hook the resistor pack after you have unscrewed it

 

I used one of those long thin parts-grabber things, the one with the thumb botton and the 4 spring steel fingers on the end. It allowed me tp grab the old one, plus placing the new one was easy since I could move it around easily and line up the screw.

WYAIT's: While the resistor is out, take the opportunity to peek in there at the AC evaporator. If it's dirty and mud-caked as most are, you may want to take the time to clean it while you have some access. Moisture condenses on the fins when the AC is running, and any dust that is in the air will manage to stick to the moisture, eventually restricting airflow and making the AC a lot less efficient. if you can get the skinny shop-vac nozzle in there it's a start, but usually it takes some actual washing of some kind to get all that stuff to where it will get sucked up by the vacuum. Be carfeful not to bend the fins if/when you decide to get in there with a stiff brush. There is a drain hose for condensate that goes down to an opening above the cats in the middle tunnel. You can flush a lot of stuff down that hole but don't try too much at a time to the point where you plug up the hose.

 

i wish I had thought to use the parts grabber, I skinned up my hand trying to reach in there.

 

Go to our web site, click on the photos to enter, click on Tips & Links, click on Wally's World, click on HVAC, download, print and read.

Let us know if we can help. Call Jeannie at 828.766.9280 to order any parts that you might need.

 

Thanks all. I will try over this weekend. Question, I found this picture that shows the part I need as well as the location. Just want to make sure this is a good picture - I found the same on my vehicle as far as location - 928.616.101.00 - Position 37?

Also checked the fuses and relay and they look good. Tested with a new relay and replaced a few fuses (original fuses were fine) and same results.

Thanks!

 

did you do any work on the console prior to the fan not working?? is it possible that the wire connector to the fan switch isnt connected??
What was the last thing that you worked on??
The picture you posted is the correct place for the resistor group #37