I changed the fan blower motor in my 89 240dl a few days ago. As I am only finding out now, there is another component that "commonly fails" in the center of that endless pit (A.K.A. the location of the fan blower motor) that I didn't know about at the time. As luck would have it, I believe the (heater control valve) may be faulty. Well the way I feel about it right now, my grandmother would have to be stuck inside the blower motor casing before I would even think about tearing right back into it again. And I'm nearly certain that anyone who has done the swap themselves can relate to any frustrations I may have about this. Anyway, my question is this: IF it's possible to by-pass the heater control valve by running the two heater hoses together, CAN the heater control valve therefore be safely eliminated WITHOUT affecting the Air Conditioning system? Don't need heater; a\c a must. Any help to my question would be greatly appreciated. Thank you very much.

As others have mentioned the heater valve is relatively easy to access, nothing on the order (or ordeal) of the fan motor.

This link shows the procedure as performed last year on my daughter's 1984 245 "Buster".

ADVENTURES INSTALLING A SCANTECH HEATER VALVE

Regards,

Mike

Hello Mark,

I know you have posted on several subjects in a number of threads I have not read, and at least one where I offered a response, so forgive me if I am missing a point.

If you put your fingers on the heater hoses, finding both hot, even though the heater control cable has the valve as completely closed as possible, the valve's seating may have deteriorated beyond help. However, that is not so common as a failure of the capillary feedback device meant to regulate the air temperature.

In some cases you can extract some more life from the valve by adjusting the regulation mechanism as shown highlighted in the picture below. If you want to stop all the heat, you might be able to simply drain the coolant, pull the inlet hose and fit a rubber stopper into the hose before reconnecting it-- a slightly easier task than trying to bypass it under the hood with the exposed old molded heater hoses. Relive your Blower Motor Replacement Experience

The heater core is buried in the dash, but the control valve is inside the console near the gas pedal. Drain your coolant, then remove the driver's side console panel. Follow the cable until you find the valve (you will see the heater hoses and a copper wire running into the valve). Relatively easy to replace.

No offense, but are you sure that you are operating the heater controls the way those goofy Swedes intended? In your last post, it sounded like you had the heater control on at the same time as the A/C. You want to make sure that the heater control level is pushed all the way to the left before turning on the A/C. It could be that the cable needs to be adjusted such that even with the level maxed out to the left the control valve is still open.

"heater control level" = "heater control lever."