What does it look like
 

Could you please post a picture of that resister for the W123. Sure would like to know what it looks like and where it lives.

I think this discussion is all about a device called the 'blower motor regulator', rather than the 'resistor', even though it may be, in fact, a resistor with a huge aluminum heat sink attached to it.

The Mercedesshop parts dept has two for 1990 2.5 turbos, one if there is a filter, and another if there is not. The non-filter item is triangular in shape.

If one were to replace it with a resistors (or resistors) of a more generic sort, what would be the best way to do this?

http://catalog.worldpac.com/mercedesshop/sophio/part.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&cookieid=24N0VNH5B24N0VNNHL&baseurl=http ://catalog.peachparts.com/&year=1990&make=MB&model=300-DT-003&category=R&showChildren=false

jesus...i'm going to pull some at the pull-a-part too.

could someone point me to a part number or a location of said part?

danke

It's not the part number you are looking for. You will need to find the resistance value of your part and go from there and make your own. www.tubesandmore.com has several Ohmite brand wire would resisters on a heat sink porcelain tube that you can modify that will take the wattage and the heat! Is yours totally damaged? Or just burned through in a spot or two? Because if you can temporarily connect the broken citcuit of the damaged area and use your voltmeter to get a reading from all taps, then you will need to fashion a voltage divider network at those same resistance values from some high power resisters and make your own for less than $50.00 that will last the life of your car! Hint....Find the curreent duty rating of your fan motor and put a inline fuse of LRA between the resistor and your motor and if your motor fails, your fuse will protect your circuit! When finished you can christen thee "The immaculate contraption"!:D:D:D:D

It's either a passive voltage divider, or an active voltage controller. The passive units are around $20 for an American car, and around $125 for my Saabs. One of my Saabs has an active controller, and I think it's over $200. My guess for the $300 you're getting an active fan speed voltage controller.

It is not a resistor, it is a variable-voltage output regulator of sorts. The porcupine part is a heat sink, the electronics inside vary the voltage output (and therefore blower speed) smoothly per the control voltage from the ccu.

I keep a couple of good used spares around, had to replace the one on my '91 just after the warranty expired, it was expensive. When the blower starts to draw too much current, it will eventually toast the porcupine. Hear a squeak in a 124? Spend the 1/2 hour to R&R the blower motor.

About as expensive a mistake as letting the Aux. Pump draw too much current and destroy the CCU.

on the W123.. passenger fender area just before the wheel hump. there is a cube with a bunch of holes in it and a spring looking thing in it.. That is your $357 resistor

http://i3.photobucket.com/albums/y74...uperturbo3.jpg

see it.. (not my car.. I wish)




seriously next time I go I am pulling all of them that I can find and will figure out if they are good and list em on egay for like 150$ each

don't feel to bad the turn sig relay in the 97 E300D I had was located in a $400 module. after paying 4 bills for mod and installing myself to fix a $15 problem I traded the German POS for a Dodge PU with a Cummins in it and vowed never to buy an MB newer than 90 or maybe 85. The 97 was THE WORST CAR I ever owned. One problem of junk materials/stupid engineering after another. Better to have a NAZI make your car than an international banker--- the NAZI's had some honor, bankers have none. 88's

Sorry about the $300 for the blower regulator. I just took the same hit. Couldn't believe it, either. Coupled with the price of a blower motor, it was an expensive job.