Ventilation FAN & Resistor Pack =============================== Problems & Fixes Ed: Jan ----------------------------------------------------------------------------- From: jhamill@bbn.com (John Hamill) Subject: Re: Vent Fan problem on 89 Jetta GLI Date: 24 Apr 92 18:49:46 GMT >>The ventilation fan on my 89 Jetta GLI works only on the 4th level, when >>I turn the knob to any of the first 3 levels nothing happens. I brought >>it in to a VW specialist, he told me that the variable resistor had to be >>replaced. I got it replaced and it worked for a while before it went out. >>I was told it was probably a bad part and had it replaced again. It worked >>for about 45 minutes before it went out again. Now he is telling me the >>fan motor for some reason is putting out a high amperage causing the >>variable resistor to go out. He suggests replacing the fan motor. Before >>I invest money on a fan motor, I'd like to know if anyone out there has >>heard of this problem. > >This is a common problem in AC equipped Jetta GLI's of 85-89 vintage. >VW apparently used underrated resistors in the resistor pack and they blow >due to the current draw of the fan motor. MISC: it is possible to replace one of the resistors. Although I have never done it, I know someone who did it with regular Radio Shack parts. ------------------------------------------------------------------------------ From: dans@panix.com (Dan Simoes) Newsgroups: rec.autos.vw Subject: [w] Replacing the resistor pack Date: 15 Sep 1993 23:43:33 -0400 Organization: PANIX Public Access Internet and Unix, NYC Lines: 45 Message-ID: <278nd5$sdj@panix.com> NNTP-Posting-Host: panix.com What: replacing the resistor pack (ac/heat fan related) Why: fan only works on speed 4, no 1,2,3 Parrts: reistor pack, $29.99 from Rapid Parts (914-357-6611) or dealer Tools: small and large Phillips screwdriver, and/or power screwdriver Time: 20-30 minutes (maybe more with knee bar) Begin by clearing out all the junk in your glove box. Then, remove the screws holding the tray or knee bar below the box. You can now see the blower motor, but not completely. Open the glove box, and begin to remove the screws around it. Then, inside the glove box, you'll see 3 plugs. Remove these so you can access 3 more screws. By now the glove box will be loose. If it hasn't already fallen out, pop out the glove box light. The glove box should now come out easily. Now, spot a 4 wire connector to the left of the motor. It is attached to a silver plate with a screw. Squeeze the connector on the sides to loosen it, and then remove the screw. This part is the resistor pack. Pry it upwards if it is not loose, and it should come out easily. Installation is the reverse of removal. I recommend you test the new part before putting everything back together. This worked on an 86GLI based on procedures listed in Bentley. I recommend you check there before beginning. In case you're wondering why this fails so often, my mechanic explained that there is now a newer motor that draws less current, so as to avoid this failure. Basically, the old one (which most of us have) draws too much current, causing the pack to overheat (notice where the pack is installed - near an air intake, so as to cool it!). To my surprise, running at 4 will not cause failure, since at this speed the pack is completely bypassed. It's at lower speed, when the resistances in the pack are being used that they overheat (makes sense when you think about it...) Hope this helps some of you. It was very easy and I recommend doing it yourself over giving it to a mechanic. Some things like CV joints and exhausts are better left to others... :-) | Dan | -- Dan Simoes Voice: 914.747.2900 x415 Danix Consulting email: dans@panix.com or Yorktown Heights, NY dans@danix.uucp ------------------------------------------------------------------------------ From: reinert@crocus.cs.odu.edu (Ken Reinert) Newsgroups: rec.autos.vw Subject: RE: [w] Replacing the resistor pack Date: 16 Sep 1993 12:56:28 GMT Organization: Old Dominion University, Norfolk, Va dans@panix.com (Dan Simoes) spoke about: >What: replacing the resistor pack (ac/heat fan related) >Why: fan only works on speed 4, no 1,2,3 >Parrts: reistor pack, $29.99 from Rapid Parts (914-357-6611) or dealer [procedure deleted] >In case you're wondering why this fails so often, my mechanic explained that >there is now a newer motor that draws less current, so as to avoid >this failure. Basically, the old one (which most of us have) draws too much >current, causing the pack to overheat (notice where the pack is installed - >near an air intake, so as to cool it!). I had this problem occur on my '87 GLI several times. After buying one of the resistor packs from the dealer and replacing it myself, I took a close look at the deceased one. Prodding the thing with an ohmmeter showed that the resistor was functional, but the thermal fuse blew. I replaced it with a new one (Rat Shack sells them, $1.29 each in the '94 catalog), and voila! functional resistor pack! No, I don't remember what temperature rating I used... RS offers three of 'em: 128c, 141c and 228c. Oh yeah - soldering on the new piece is *tricky* since the leads of the resistor don't take to solder too well. Also, use a heat sink on the fuse lead, or the heat will kill it. Ken