Posted by Shawn Anderson on August 13, 1998 at 22:11:30:
In Reply to: Fan speed resistor pack? posted by Ben on August 13, 1998 at 17:35:24:
: Hey folks, my HVAC fan will intermittently cut out at all speeds except "4" (the fastest position). I understand from reading some E36 posts on the BMW digest that it is a common problem with a particular resistor pack. The car in question is actually an E34 535i, but I bet the problems are probably one and the same. Can anyone explain to me what is exactly wrong with these pesky resistors, and how to fix this annoying problem? Are the resistors buried deep in the dash, under the backseat, or what? Do they need to be cleaned, replaced, or sharked? Please help, before my eyebrows blow off of my face!
: Thanks in advance,
: Ben Trapp
Depending on the year, your E34 either has a resistor pack or a "final stage" unit. Both do the same thing. Here is the breakdown of the various HVAC systems in the E34
1988-1990 (6 cly) IHKR I system
1991 (6 cyl) IHRR II system
1992-1995 (6 Cyl) IHKR III system
1994-1995 (8 Cyl) IHKA system
Cars with the IHKR I & IHKA systems have the "final stage" to control fan speed. It is also called "the sword" because it kinda looks like one. You remove this one from the passenger side of the HVAC system. You need to remove the glove box as well as the panels on the side of the HVAC system. Look for a green 5 pin connector in the back area. The Final Stage is held in by 3 screws. The unit slides into the HVAC system so it doesn't look like much until you pull it out. It is expensive, but you can get them aftermarket and through ProgRama in Florida for about $170.
Cars with the IHKR II and IHKR III HVAC systems use the resistor pack. It is located on the diver's side of the car. You need to remove the carpeted area by the gas pedal. It looks like it is in the back of the HVAC system and has a 4 pin connector. This is fairly inexpensive I think.
I was helping a guy with a 1991 M5 and he seemde to have a final stage even though the Bentley says he should have a resistor pack. Keep that in mind if you cannot find one or the other.
1990 535, 152,000 miles and oh so strong...