jf951

sorry for the simple question, but my heater/ac fan only works on 4 (full blast)
is there a resistor somewhere that can be cleaned or replaced. thanks.

testarossa_td

What model year?

jf951

89 turbo s

testarossa_td

It could be bad solder connections, it could be worn contacts...or something different all together.
Depending on how adventurous you are....
You can disassemble the unit and see which.
The easiest solution is to buy a crummy one that had other issues(ac switch or whatever) and swap out that part. Solder time.(I know this guy has a few bad units) 44andmoreparts.com

I have seen and have had some that were intermittent like that and sometimes it worked sometimes it did not....sometimes you could bang on it and it would work...which led me to believe it was a bad contact point.

MichelleJD

Do the 944's have a high blower relay like GM cars? I don't think so. I think you'll find the HVAC "brain" is fried. I went through 3 of them on my N/A. They usually run around $150-$250 on ebay.

EDIT - just saw td's reply. Make sure if you get another controller that it's an 87 or newer. The 85.5' and 86's cannot be taken apart like the newer units. Ask me how I know

bearone

the ballast resistor on top of the blower assembly is dead or dirty and will only give the hi speed.
$165 thru the dealer only.

87951

jf951

thanks!

JDeitz951

Typical problem no 1-2-3 and only 4. Resistor pack under the plastic cover at the rear of the engine compartment needs the contacts cleaned. Release the seal on top of the firewall and bend the cover up a bit to reach.Two phillips screws, be careful not to break, delicate.

jns

There's another topic I saw since I have a completely dead blower. Someone used a couple of drops of battery acid to clean the contacts with good results. You can also slide some sandpaper in between the contacts to clean them. Good luck.

hosrom_951

I have a "working" blower resistor if you are interested. I used it myself on the car (for testing only) and all 4 speeds on the blower worked. PM me if you need more info!

You could clean it and it MAY solve the problem, i never experienced that particular problem, but i switched between two resistors to "see" any difference, there was none.

jf951

i'll try cleaning this one up first. but thanks, i'll pm you if i need it.

ehall

This is out of left field but it happened. Check the battery cables. If you have already, see all above and go ask Clark at his Garage, BUT, You just wouldn't believe how many of my electrical probs disappeared with 2 new battery leads, new relays all around, and new fuses. If you raced past "both battery cables", you have failed the test. 99% of my probs went poof after replacing both battery leads.

db944

Not trying to be a smart ***, but have you checked to make sure the defrost button is not depressed? That overrides the fan and it only works on "4". Ask me how I know..... :-)

slivel

It's mostly likely that the resistor pack has some failure. Most commonly it is the contact points that are dirty or are too far apart to close. The contacts are intended to open the circuit if the resistor(s) overheats. My pack on my 89 T failed for a different reason - one of the resistors had an open (no continuity). I consulted the factory schematic and found a 10 watt resistor at radio shack and soldered it in. It's been working fine ever since (about 4 years). The fan works on speed four because on four, the three resistors in the pack are bypassed. On speed one all three resistors are used in series. On speed two two of the resistors are used in series. And on speed three, only one of the resistors is used. Not a hard fix if you can use a soldering iron and can find a repalcement resistor. Good luck.

testarossa_td

So much good info! Viva la Rennlist!