Currently working on area below wiper mechanism area. Trying to do things that make the car more reliable for future use.

I'll be pulling the regulator to gain better access to the top of the evaporator for vacuuming and flushing of the evaporator with a spray cleaner and water.

Since I have it out is it a good idea to replace it? Car has about 67,000 original miles.

Old original blower motor brushes were 50% worn, I'm replacing it with a new Bosch motor due to its age and not knowing what the proper lubricant is. Bearings appear to have a solid lubricant built in, so I didn't want to add a liquid lubricant.

If so, anyone have experience with AIRTEX/WELLS 4P1828 for the regulator?, touted to be better made than original and is 'plug & play' to existing cable.

Who's to say whether a new module will be any better. Hear of "Infant mortality syndrome"? It has nothing to do with babies, but is a phenomenon used to describe the likelyhood of an item failing with regards to time and usage. Think of an inverse bell curve with a flat bottom. The solid state regulator should last decades or hundreds of thousands of miles. If you're concerned about it, replace the thermal grease on the heatsink and button it back up.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

No. The one in mine made it to 292k miles.

__________________
Jim

Thanks for the replies, now I'll be keeping my old one in place.

Adding a few pictures of my 95 E300D fan resistor regulator. Different than I expected.

The good, it is easy to remove the electronic part. IMO do not think about removing the heat sink. I did because I wanted to clean the evaporator of old foam rubber and dust. Foam rubber from big flap above the evaporator.

The bad, I broke the left and right side of the fan's bottom plastic plenum while removing it. Took over an hour to remove two little screws holding the front side of plenum in place. No room for access with normal tools. They would put screw in from back instead of the roomy area on the other side. After removing the two screws plenum front was loose and heat sink was easy to remove at that time.

I wanted to remove the evaporator grill and thought I could 'unsnap' the fan bottom plenum but two areas were too tight and broke. Easy to get evaporator grill out after that.

No reason to remove that grill or heat sink as I did, unless your evaporator is pretty dirty.

I'll use Permatex black silicone to seal the cracked areas. I'm not concerned with causing a problem because there are 7 screws that hold most of it in position, plus the two side areas that should come loose but never.

So repeating, if your fan area looks like mine, don't remove the heat sink or attempt to remove the lower plastic fan shroud. Just remove the bottom fan mount and unscrew the blower regulator by removing the two screws holding it to the heat sink. Just clean the heat sink and apply a thin 'X' pattern of thermal paste or a very thin smooth layer of thermal paste. Thicker is not better because thermal paste should be really thin, just enough to fill in impections in the metal surfaces being joined. Thick acts as an insulator.

One of the pictures above shows how it looked before I did today's work.

Attached Thumbnails

       

One picture didn't upload.

Attached Thumbnails

 

Today, after quite a while, I was able to get the plastic lower plenum back in place. Took a little Permatex black silicone to fill in the cracks where I tore it during removal. Luckily it has 7 screws to help hold it in place.

Again, in my opinion do not remove the plastic plenum that goes beneath the fan. Also do not remove the heat sink, just clean it & use a good brand of thermal paste with a thin coating.

If you have the grill between the fan & evaporator & you want to vacuum that area then just snip out the grill to gain access. Doesn't look like the grill serves any good purpose.

I also fitted the new fan motor with my old plastic fan wheels. Fit in quite easily after having to adjust the wheels 1/8" to the left to avoid hitting plenum. The fan motor doesn't move left or right because it fits into a slot on the left side of the lower fan cradle.

My cost for the new Bosch motor & having the wires soldered on & the fan wheels put in place was about $100. Still don't like that a German made fan motor was not available from Bosch, mine shows Brazil as country of origin,

Picture shows fan running. It is quiet & smooth with no vibration. Tomorrow I plan to wrap the wires with some electrical tape to help reduce chance of insulation being cut by the metal retaining strap.

Attached Thumbnails