Date:         Thu, 17 Jul 2003 09:36:30 -0700
Reply-To:     mark drillock <drillock@EARTHLINK.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         mark drillock <drillock@EARTHLINK.NET>
Subject:      Re: 2.1L coolant light problem
Comments: To: SStones <sstones@IDIRECT.COM>
Content-Type: text/plain; charset=us-ascii

Well, what you describe does not apply to 2.1 models which is what we
are talking about. The fan motors in the 2.1 have only one set of coils.
Large external current limiting resistors are what set the actual speeds
the fan motor can turn at. These large external resisters are a common
failure part in 2.1 models, particularly those with A/C.

In high speed, no resistor is in the circuit. Low and middle middle use
2 and 1 resistor respectively.

Mark

SStones wrote:
>
>
> Power is supplied at all times to the thermo-switch in the radiator. It has
> 3 possible positions. When cold it is an open circuit, when hot it closes
> the circuit to one set of coils (low speed) in the fan motor. When really
> hot it closes the second circuit (While keeping the first circuit closed).
> and that energizes the relay which supplies current to the second set of
> coils (High speed) in the fan motor and the fan runs fast with both sets going.
> The AC system also has control over the relay, and will close it to supply
> current to the High Speed circuit of the fan regardless of what the
> thermo-switch is doing. So if the engine's cool enough the fan will be
> running at a medium speed that the non-AC vans never run at. If the
> coolant's hot enough to close the low speed coil, the fan will of course
> run at high speed with the relay closed, because both sets of coils are
> supplied.
> If I have mis-read the wiring diagram, Flame away people.  I have the
> asbestos underpants on.