[mika]

Hi all,
I have a new to me 1990 sierra that i'm getting ready for a RWC but the blower fan only works on the fastest speed. I managed to get the blower switch out with out removing the entire dash. i have cleaned up the switch well and checked all the wiring and plugs i can see that go to the fan motor and still no difference.
Does anyone have any ideas as to what it could be? I suspect it's either the switch is buggered, electric motor buggered or a bad connection that i can't see but thought maybe someone has had similar experience.

Aslo, anyone know if all 3 speeds need to be working for a RWC in Vic?

thanks in advance
mika

[BJPK]

usually the fan speed resistor will be the cause.

[Scrawny]

BJPK wrote:

usually the fan speed resistor will be the cause.

x2. Usually found in the heater box

[mika]

thanks, do u know where the resistor is ?

[zookfun]

my zook has just started doing this too

[mika]

thanks ScrawnC, you beat me to it.
Can you access it without removing dash?

[v.w.dave]

ScrawnC wrote:

BJPK wrote:

usually the fan speed resistor will be the cause.

x2. Usually found in the heater box

X3 this is the same for most cars. Highspeed on the fan speed resistor is a Bypass, in short it allows the full 12 volts to pass through to the fan causing full speed.

[mika]

what do i need to do to fix it? i'm guessing replace it but what's involved?

[Scrawny]

It's usually pretty easy to access without removing too much. I'm Zookless now so I can't go have a look for you

[royce]

look above the fan motor via the drivers footwell youll see a plug that looks lke it plugs into teh heater box, thats the resistor, to get it out unplug it and undo the 2 screws that hold it in

once out youll probably find the bimetal strip on it has dirty contacts and cleaning them with some sandpaper will fix it, normally when no slow speeds work its that and not eh resistor elements, which are the little coils of wire, check they arent broken

[mika]

thanks a lot guys,
I'll check it out tonight.

[mika]

thanks for the detailed info Royce. Well the resistor elements are broken and very brittle so i need new ones.
anyone know where i can get new resistor elements from?

[Scrawny]

Try Suzistore first, otherwise go genuine. Shouldn't be too dear

[royce]

shit I think I just chopped some up that were perfect

I will have a look if you get stuck and cant get one, how far is Yarra Valley form Bulla? the unused resisitor and I will be there in a month or so

[mika]

just looked on Suzistore before and not listed but i might give them a call. I ordered some bits from them a week ago and great service from them.

Royce Bulla would be about 2hrs from here so hopefully i can get one sooner and with less travel but thanks for the offer, appreciate it.

[jonno_racing]

mine does the opersate... no full speed but works on other speeds???

i will check that plug latter on though.. broken wire?

[mika]

could it be that the switch that needs cleaning? thats what i checked first, i got it out without removing the whole dash