[Guest (MBNZ)]

I have a cabin heater blower fan that is intermittent. With just the key on, ( 12volts), the fan operates normally. When the engine is started, (Approx 14.4 volts), the fan quits or operates very intermittently. The fan switch has power to it with just the key on and also with the engine running. The switch has been replaced, but I still get the same symptoms. All fuses have been checked. No other electrical problems. Any ideas?? Possibly a relay? Thanks for your input.

 

[Guest (MBNZ)]

Just a shot in the dark, but check your vacuum valve (switch??) and hose on the passenger side of the blower cover.

 

[Guest (MBNZ)]

Thanks for input, I have checked the vacuum diaphram, which I believe is called a mono-valve, in-line with the coolant supply to the heater core. It is normal. So is the in-line pump prior to the diaphram. I have heard the push button units are prone to internal solder/circuit failure. My car is a 1990. I have also been having temperature control difficulties for the past few months. Maybe these are related. If anyone has any other ideas or a good source for these push button units I would appreciate it. Thanks, Mike

 

[Guest (MBNZ)]

Mike, drop me a line @ [email protected] and we'll get you set up with the unit you need.