RE: heater and defrost fan and control

From: Robert Setree (agm@agm.win.net)
Date: Sun Jan 20 2008 - 18:54:03 EST


No speeds work. I have voltages on some terminals. I will take it loose
and look at the windings. 50 amps probably leaves some tracks when it
fails. If it looks ok I will get voltages and wire colors.

-----Original Message-----
From: owner-dakota-truck@bent.twistedbits.net
[mailto:owner-dakota-truck@bent.twistedbits.net] On Behalf Of David Gersic
Sent: Sunday, January 20, 2008 1:47 PM
To: dakota-truck@dakota-truck.net
Subject: Re: DML: heater and defrost fan and control

On Sunday 20 January 2008 12:34 pm, Robert Setree wrote:
> My defrost fan stopped running. My electrical diagram shows the resistor
> bank and I find 12v there.

It's most likely a failed resistor here. Do any of the fan speeds work?

> I don't see how the battery or ignition switch
> sends power to the fan.

At least on mine (2001), power comes in to the resistors, which is really
just
one length of resistor wire wrapped around something, with multiple taps
coming off it. Each tap increases the resistance, slowing the fan down. The
fan speed selector switch selects one of these. Depending on voltagwhere the

resistor wire fails, you can get no, one, or only a couple of fan speeds.

On mine, this is an easy replacement part. It's located in the passenger
side
footwell. Earlier models have it up in the dashboard, and you have to get at

it by removing the windshield wipers and cowl cover.



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