Blower motor only works if AC button is pressed
Blower motor only works if AC button is pressed
Apologies if this has been covered before, I tried to search for similar issues but didn't find anything. I'm wondering why my blower motor only turns on if I have the A/C button pressed? All of the fan speeds work as they should when the button is pressed, but the blower doesn't engage at all if the A/C is off. Could this be a relay issue? I have an '88 535i 5 spd. TIA!
Re: Blower motor only works if AC button is pressed
E28 have two blowers....one starts without AC button pressed (fresh air Blower) and the second one start when AC button is pressed (AC Blower). So you now have only the second one working when AC is engaged.
Re: Blower motor only works if AC button is pressed
Welcome to the group AdamHan!
As Aldo explained there are two different blowers. The good news is the one that isn't working is the easy one to get to, it does heat, defrost and fresh air, the A/C blower down by your knee just does A/C. Wiring diagrams are here, http://wedophones.com/BMWManualsLead.htm
It could be a variety of things from the snowflake switch to the blower speed switch or the blower motor itself. My guess would be the blower itself which is accessed from the engine side behind the removable panel at the top of the firewall. To complicate things there are two different brands of blowers that are kind of sort of interchangeable one way but not the other. There's a variety of options if you need to replace it.
As Aldo explained there are two different blowers. The good news is the one that isn't working is the easy one to get to, it does heat, defrost and fresh air, the A/C blower down by your knee just does A/C. Wiring diagrams are here, http://wedophones.com/BMWManualsLead.htm
It could be a variety of things from the snowflake switch to the blower speed switch or the blower motor itself. My guess would be the blower itself which is accessed from the engine side behind the removable panel at the top of the firewall. To complicate things there are two different brands of blowers that are kind of sort of interchangeable one way but not the other. There's a variety of options if you need to replace it.
Re: Blower motor only works if AC button is pressed
Awesone thanks so much! Never would've guessed there'd be two blowers!
Re: Blower motor only works if AC button is pressed
Important fact is the two blower doesn't work simultaneously....I mean, without AC the fresh air blower is working and AC blower is off, with AC working (snow flake button pressed) fresh air blower is off and AC blower is working, but no two blowers at same time. (At least euro cars like mine)AdamHam wrote: Apr 17, 2024 2:12 PM Awesone thanks so much! Never would've guessed there'd be two blowers!
Re: Blower motor only works if AC button is pressed
US cars as well.Aldo525 wrote: Apr 17, 2024 4:19 PM Important fact is the two blower doesn't work simultaneously....I mean, without AC the fresh air blower is working and AC blower is off, with AC working (snow flake button pressed) fresh air blower is off and AC blower is working, but no two blowers at same time. (At least euro cars like mine)
Re: Blower motor only works if AC button is pressed
I've had this issue for a while in my car also and did test the fan (which was replaced with a new one and worked prior to getting to its current state). I replaced the snow flake switch as it switches power to the fan but that didn't fixed it. Also replaced the resistor pack (one speed wasn't working) and still it won't work. I took a wire from the battery to the fan and it runs so something in the circuit is not right. Still trying to see what is it that could hinder it's operation.