Something I have done recently is replace the 2 speed front heater
resistor with a 3 speed one from the rear a/c. This allows a 4 speed
switch to be used on the front heater, with 3 speeds going through the
new resistor. High speed bypasses the resistor in any case.

   old
speed 1 ~ resistor low
speed 2 ~ resistor high
speed 3 ~ direct to fan

   new
speed 1 ~ resistor lower
speed 2 ~ resistor med
speed 3 ~ resistor higher
speed 4 ~ direct to fan

This was done to replace a burned out heater resistor NLA, with a more
easily found a/c resistor. Could have wired up with 3 speed switch
feeding the 3 speed resistor, leaving out the direct connection for
speed 4 but the owner wanted all 4 and we had the switch. Time will tell
if the new speed selections are ok. We also used a a/c fan to replace
the bad heater fan. Same part other than slight wiring mod.

Mark

Dennis Haynes wrote:
> Sure sign the blower motor is about to seize of otherwise fail. Fuses should
> never just be replaced without the cause being determined and corrected.
> Also, as I have written in the past there is no real reason or benefit to
> operate the dash heater fan on that high speed. The interior will warm
> faster along with the windshield defrosting with the fan on speed 2. Once
> moving on the highway turn it off to save it.
>
> Dennis
>
>
> At 07:43 PM 12/27/2009, David Cohen wrote:
>>   The switch keeps sticking  in the
>> third position.   Where do you recommend I buy a switch  from?
>
>