Technical interior fan speed dial not working

[JeremyT]

HI Guys,
I have a 2013. Jumped in the van today and went to turn a/c on as I do everyday. but the fan didnt blow any air. There are 4 speed settings 1,2,3,4. 1,2 and 3 blow nothing but 4 blows as usual on highest speed.
Any ideas? Thanks

 

[varesecrazy]

HI Guys,
I have a 2013. Jumped in the van today and went to turn a/c on as I do everyday. but the fan didnt blow any air. There are 4 speed settings 1,2,3,4. 1,2 and 3 blow nothing but 4 blows as usual on highest speed.
Any ideas? Thanks

Hi.

The speeds are controlled by a BIG resistor.. it drops voltage from 12.. down to 9,6,3

So.. youve lots the voltage drop effect


It gets HOT so can cook..and damage the wiring

SEARCH 'resistor pack' here on the forum

Charlie

 

[rayc]

Here is the wiring diagram. It shows the resistor pack in the negative to the motor. On position 4 the resistor pack is bypassed

 

[Anthony489]

Hi Jeremy

The resistor pack also incorporates a thermal fuse, which is a little cylindrical component filled with low melting point solder. If anything restricts the airflow, like a choked pollen filter, the resistors get very hot (rather than just hot) and the thermal fuse goes open circuit to protect from fire. Sometimes they can go just due to old age. Once the fuse is open circuit you lose all speeds other than 4.

The resistors themselves are of two types. One has wire within a ceramic cement coating, often green. The wires can break under the coating, and then you typically lose one or two speeds. The other type has open coils of resistance wire, which are much less likely to fail.


Resistor packs aren't horrendously expensive, but I would avoid cheap chinese copies. In my experience these have thermal fuses with too low a temperature rating and they fail again within a short time.

If you are skilled and adventurous you can buy a kit to replace just the fuse, it has to be crimped to withstand the heat.

 

[varesecrazy]

Nobody pointing location..or access?

 

[RS3100]

Nobody pointing location..or access?

https://www.motorhomefun.co.uk/forum/threads/x250-ventilation-fan-faults-fixes.100160/

 

[JeremyT]

With all of your help I realized that it was a bad / dirty connection into the resistor. Working again properly now! Thanks again for all of your help!