Hi Speed Push Button
 

Hi,
I have a '95 E420 with about 96K. It runs beautifully and is a pleasure to drive.
I noticed that there is no increase in fan speed when I press the upper button on the climate control system.
Any ideas on why?
Anziani

When the auto is selected for a min setting the system goes to high speed..

ONLY when the inside temp is almost equal to selected temp will the speed be slower than high.

Hi Speed Pushbutton
 

M.B. Doc,
Thanks for the response. My problem is that when you push the "hi" button, there is no increase in fan speed like my '87 300E. Yes, I have a normal fan speed when I first start the system. In the 300 E if I push "Hi" then the speed substantially increases. Not so with the E420. I don't know if I have a problem, maybe a design change?
Anziani

I'm having the same problem. It started last week when I couldn't get the fan to come on at all. It came back after a few minutes luckily. Not fun in the San Fernando Valley at 106 degrees, and I'm sure worse in PS.

My guess is tha the fan motor is on it's way out.

Craig

High button out
 

This is just a guess based on stuff I'd previously read. It sounds like the soldering is bad on the flip side of the button. You'd have to take the panel out in order to solder the connection.

Good luck with it, and again, this is just my guess. Some people even hit their panel to sometimes make that connection work. If it does go in and out based on bumping, it's definitely the connection.

1991 300d