thanks Mark...

on my others Vanagon I get 1200RPM at idle with A/C on and not 2K RPM, I
think it's too much but 1400RPM is acceptable.

dan

On Fri, Oct 17, 2014 at 10:34 AM, mark drillock <mdrillock@cox.net> wrote:

> The idle is supposed to increase when the A/C is on. There is a wire
> from the A/C compressor clutch over to the idle control unit so the idle
> control unit will know to increase the idle speed so the A/C doesn't
> stall the engine. I don't know what the idle speed rpm increase is
> supposed to be but maybe someone else does.
>
> That year should have the later trinary pressure switch and this could
> be giving a false indication of a need for medium fan speed. Or maybe
> someone could have fooled with the wiring to make it do this?
>
> Mark
>
>
> Dan N wrote:
>
>> hi all,
>>
>> 1990' Carat - recently purchased - rebuilt engine - smooth idle 950 RPM -
>> A/C recently serviced, cold air, new fan switch.
>>
>> When I turn the A/C on the idle jumps to 2000 RPM - the fan goes to medium
>> speed all the time.
>>
>> What part or parts that triggers the idle?
>>
>> What part or parts that triggers the fan?
>>
>> please help -  I search in the archive and only found an April 2000
>> article
>> about this..
>>
>> many thanks in advance
>>
>> dan
>>
>>