heater fans not working

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flossdog

flossdog

New Member
Posts
93
Location
Bulgaria
Cant get the fans to work on my car...I have;

Changed to motors.
Changed fusebox and relays
Tried a known good control panel

They do not run at all but while doing something else I connected the battery with the key in position 2 and the ran right away. They would slow down and speed up but when switched off they wouldnt start again!!

The car has had 2 Becm in last week so Im thinking it isnt an internal fault.
Anyone got any ideas?

No fans= No AC and its getting warm out here..
Cheers
 
Morning, I had a similar problem with my 99 HSE when i first got it, the fans wouldnt turn up, I ended up stripping the hevac unit and found the rotary contact in the fan speed dial had come off its pins, i glued it back onto the pins, adjusted the tips down a bit, refitted and i now have adjustable fan speeds.( occaisionally it can take a bit of rotating to wake it up but it goes from min to max eventually!:eek:) I am planning on replacing the hevac when i get round to doing the blend motors but i can live with it.:)
Hope this is of some help
 
wammers said:
You have had ideas. What do you want, someone to come and do the job for you. Have you tried diagnostics?
Click to expand...

Yes I have had ideas and implemented them......none of them worked. Diagnostics said motors..it isnt the motors (unless I bought 2 duff ones) so maybe you can understand why Im still asking?? I have checked and/or changed everything suggested on various sites.. Seems odd that they start when I connect the battery and that the speed control works in that case too...It just seems not to get the "start" signal
Datatek suggested a sensor and said if it was faulty the motors would run slowly if that sensor wasnt getting the right signals. My motors do not turn at ANY speed ever.
Prob not very much but far from obvious....
 
flossdog said:
Yes I have had ideas and implemented them......none of them worked. Diagnostics said motors..it isnt the motors (unless I bought 2 duff ones) so maybe you can understand why Im still asking?? I have checked and/or changed everything suggested on various sites.. Seems odd that they start when I connect the battery and that the speed control works in that case too...It just seems not to get the "start" signal
Datatek suggested a sensor and said if it was faulty the motors would run slowly if that sensor wasnt getting the right signals. My motors do not turn at ANY speed ever.
Prob not very much but far from obvious....
Click to expand...

I suggested a sensor. And gave provisions for operation. The motors are powered from the fuse box but controlled by the Hevac unit. Each motor contains an electronic speed controller and a high speed relay. You either have duff motors, duff Hevac or no power supply. The motors if selected should run at low speed in the heat function until the coolant temp sensor on the heater feed pipe detects hot coolant, only then will the motors run fast and be controllable. You will have to check all these circuits we can't do it for you. What does diag say at the moment?
 
wammers said:
I suggested a sensor. And gave provisions for operation. The motors are powered from the fuse box but controlled by the Hevac unit. Each motor contains an electronic speed controller and a high speed relay. You either have duff motors, duff Hevac or no power supply. The motors if selected should run at low speed in the heat function until the coolant temp sensor on the heater feed pipe detects hot coolant, only then will the motors run fast and be controllable. You will have to check all these circuits we can't do it for you. What does diag say at the moment?
Click to expand...

The motors are not duff...changed them as complete units from a working vehicle....the hevac works..all motors and flaps move and the temp rises as the buttons are pushed to increase temp.. I say again..The motors DO NOT run at any speed- I have checked EVERY lead suggested and found no fault. The diag says nothing now.
I earn a good living from working on Smarts because very few people out here can, or will, do it...Mainly engines, as you will see at smartsinspain.com but they too have quite complicated electronic systems and I get round those easily. So,,Im not without a clue and only want answers from people who have had this issue, and if thats nobody...so be it.
No point giving me a hard time just because the opinions given dont sort my problem
 
flossdog said:
The motors are not duff...changed them as complete units from a working vehicle....the hevac works..all motors and flaps move and the temp rises as the buttons are pushed to increase temp.. I say again..The motors DO NOT run at any speed- I have checked EVERY lead suggested and found no fault. The diag says nothing now.
I earn a good living from working on Smarts because very few people out here can, or will, do it...Mainly engines, as you will see at smartsinspain.com but they too have quite complicated electronic systems and I get round those easily. So,,Im not without a clue and only want answers from people who have had this issue, and if thats nobody...so be it.
No point giving me a hard time just because the opinions given dont sort my problem
Click to expand...

No body is giving you a hard time. If nothing is wrong the fans should run, so obviously something is wrong because they don't. I can't find it for you from here.
 
wammers said:
No body is giving you a hard time. If nothing is wrong the fans should run, so obviously something is wrong because they don't. I can't find it for you from here.
Click to expand...

Yes, I realise its not easy to diagnose remotely.....Im going to have to do my trip without heat or AC although some heat comes through when the car is moving. Im going to buy a Nanocom when /if I get to my destination
Cheers
 
Datatek said:
There are 2 hot/cold blend motors:rolleyes:
Click to expand...

Within the heater system there are two hot/cold blend motors one either side of heater. One distribution motor (upper one at R/H side of heater unit) and two recirculation motors one in each blower unit. :)
 
In mine the motors stopped when i changed polen filters. Reinstalled the filters and the motors went back to life. Still dont know what happened.
 
You say its getting hot where you are - where are you? your location is not shown.

Do you blowers work when the demist mode is activated? engine must be running - the Heater ECU overrides the rotary switch and runs the motors at max speed. Will tell if rotary switch faulty.

Blower motors get a full battery voltage to the positive side of the blower the rotary switch controls the blowers. turning the rotary switch clockwise progressively reduces the voltage of the control signals and increases the blower speed until the blowers are earthed and then run at max speed.

Self tuning - the Heater ecu performs on occasion a self tune routine. During this operation of the blowers is inhibited and the servos are driven to full range to bed in after replacement of flap motors etc.

Check fuses 8 and 17
motor fuse 42 provides battery power to HEVAC and blend motors
Fuse 43 provedes battery power to relay 6 (aux 1)
Fuse 34 provides battery power to relay 7 (aux 2)
BeCM also provides power and speed signals.

When you got a new fuse box did it have all new relays? if not check motor relays by swapping with othet yellows.

You may also have a loose connector. Or bad earth
 
Last edited:
stopover said:
You say its getting hot where you are - where are you? your location is not shown.

Do you blowers work when the demist mode is activated? engine must be running - the Heater ECU overrides the rotary switch and runs the motors at max speed. Will tell if rotary switch faulty.

Blower motors get a full battery voltage to the positive side of the blower the rotary switch controls the blowers. turning the rotary switch clockwise progressively reduces the voltage of the control signals and increases the blower speed until the blowers are earthed and then run at max speed.

Self tuning - the Heater ecu performs on occasion a self tune routine. During this operation of the blowers is inhibited and the servos are driven to full range to bed in after replacement of flap motors etc.

Check fuses 8 and 17
motor fuse 42 provides battery power to HEVAC and blend motors
Fuse 43 provedes battery power to relay 6 (aux 1)
Fuse 34 provides battery power to relay 7 (aux 2)
BeCM also provides power and speed signals.

When you got a new fuse box did it have all new relays? if not check motor relays by swapping with othet yellows.

You may also have a loose connector. Or bad earth
Click to expand...

Im in Spain....The blowers dont work on any setting and I have tried everything suggested....nothing. The ONLY time they ran was when I connected the battery with the key in pos 2. They ran on max and responded to the speed control but when switched off they woldnt restart.
 
stopover said:
You say its getting hot where you are - where are you? your location is not shown.

Do you blowers work when the demist mode is activated? engine must be running - the Heater ECU overrides the rotary switch and runs the motors at max speed. Will tell if rotary switch faulty.

Blower motors get a full battery voltage to the positive side of the blower the rotary switch controls the blowers. turning the rotary switch clockwise progressively reduces the voltage of the control signals and increases the blower speed until the blowers are earthed and then run at max speed.

Self tuning - the Heater ecu performs on occasion a self tune routine. During this operation of the blowers is inhibited and the servos are driven to full range to bed in after replacement of flap motors etc.

Check fuses 8 and 17
motor fuse 42 provides battery power to HEVAC and blend motors
Fuse 43 provedes battery power to relay 6 (aux 1)
Fuse 34 provides battery power to relay 7 (aux 2)
BeCM also provides power and speed signals.

When you got a new fuse box did it have all new relays? if not check motor relays by swapping with othet yellows.

You may also have a loose connector. Or bad earth
Click to expand...

If 8 and 17 are duff there would be a lot more than the blower fans not working. :)
 
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