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Jim Grant's Tech Tips
'95 Honda Passport, Blower Motor Fuse Failures
Q:
I own a 95 Honda
Passport; my problem is with the blower motor. The problem started with
the blower only working when the switch was in the high position (the
switch has 4 positions 1-2-3-4). Then it quit and I found that the fuse
was burned. I replaced it and when I turned the blower on it burnt the
fuse. Is the blower bad or the switch.
A:
It is likely that the
blower motor is the cause for the fuse failure problem youre describing,
but after you replace the blower motor, youll still likely have
only one speed. Why is that? The fuse that has been failing, supplies
electrical power directly to the blower motor. For any electrical circuit
to work power has to come in and then have a place to go. In your case
the power comes out of the blower motor to the resistor block and then
waits for a path through the blower speed switch. With the blower switch
in the off position there is no path for the electrical power to flow.
When you select a speed, you create a path for the electricity to flow
and the blower motor starts working. How are different speeds created?
That is where the resistor block comes into the game. A resistor could
be simply described as a choker or restrictor that reduces the amount
of electricity that can flow. The resistor block has four different paths,
each with different size restrictors. Low or #1 on the blower switch allows
only a small amount of electricity to flow; thus a slower blower motor
speed. As you select the higher speeds you are allowing more electricity
to flow, and the blower motor goes faster. Im reasonably confident
that the blower motor needs replacing. What I cant tell you, is
which part, the resistor block or the blower switch that has failed. Each
component has to be tested for that answer.
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