Hi all,
I drive a DAF CF (rigid) . The heater blower fan only works when switched to speed 4 (max). Moving the knob to any other position simply turns the fan off completely.
Any ideas what could be causing this and anything I could try to get the different speeds ?
Cheers
“Moving the knob to any other position…”
Try sitting in the passenger seat.
contacts on the switch will be fubar’d get a new switch.
Well, it’s not my truck. Just wondered if there was a quick fix .
Adam27:
Well, it’s not my truck. Just wondered if there was a quick fix .
it really depends but it sounds like the contacts at the other points are worn within the switch
Check the relay ,if not that, more than likely the resistor pack that regulate the speed
I had that same fault in a Merc Axor. No heating/blowers at all, unless you put it onto recirculation and on the highest setting. Supposedly it had been like that for months.
My resolution? Defected it because the ‘demister’ function was basically useless, couldn’t see ■■■■… and so it was a health and safety hazard 
Funny enough, it’s fixed now. 
Adam27:
Hi all,I drive a DAF CF (rigid) . The heater blower fan only works when switched to speed 4 (max). Moving the knob to any other position simply turns the fan off completely.
Any ideas what could be causing this and anything I could try to get the different speeds ?Cheers
The resistor pack that controls the motor speed has burned out. It has burned out because nobody bothered to change the pollen filter so the fresh air flow over the resistor pack that cooled it was none existent.
The solution is to buy another resistor pack and to change the pollen filter.