Heater fan

[ed325i]

Hi, My heater fan is stuck on one speed, I cant turn it off or on to any other speeds, could this be the switch or something else?

1986 944 Oval dash.

Thanks Ed

 

[stevie d]

Might be the fan speed resistor pack . There's a guide here for sorting it and its an easy enough job . http://www.944time.com/porsche/944-fan-speed-resistor.php

 

[Panzer944]

I have the same problem - have tried the unplug/clean terminals/reconnect routine and still the fan only works flat out (position 4) so I'll be trying the second step from stevie d's helpful post (ie relay cleaning) after removing the resistor pack from the top of the blower motor housing.

In the event that the resistor pack needs changing does anyone know where they can be sourced from? I have seen them on e-bay in the good old US of A - but they are used and there's no evidence that they are fully serviceable.

Best wishes,

Rob

 

[Paul 290T]

I soldered my resistor pack up.

The pack includes bi-metallic strips that make contacts. Presumably if the fan current gets too high or the resistors get too hot the strips heat up and break the circuit. No matter how much I tried to clean the contacts on the b-m strips I could not get the fan to run on lower speeds. in the end i soldered up these contacts. Its been alright ever since, circa 10 yrs ago.

 

[Catamax944]

I have a resistor pack i took off my old parts car that was working fine ,only problem it has the plastic tabs on each side of the resistors broken off. You can have it for free if you want it.

 

[ed325i]

i will take the resistor pack off and take a look

Ed

 

[pauljmcnulty]

As this is a very common fault, and I have no idea how it works, maybe someone could explain why we can't just bypass the resistor pack? Soldering it up seems a very simple solution, but what are the possible problems from doing this?

 

[944 man]

The resistors provide the lower speeds. This is why the fan still works on speed setting #4 when the resistors fail, as this is the 'straight through' setting. On the lower settings (from #3 down to #1 (or technically even #0 as the fan is always on in a 944)) an increasingly large proportion of the current is lost to the appropriate resistor, and as a result the fan spins at a lower speed.

 

[Llewelyn]

A good tip is to soak the whole unit in vinegar which dissolves all the oxidisation from the contacts. Rinse, dry and refit and it should be a long term cure.

You could drag paper through the relay contacts but the above is a safer bet.

Hope this helps!

 

[Mike_Pollock]

Hi Llew Remembered the login I see[]

 

[Llewelyn]

Oh yes