1987 Chrysler Lebaron A/c / Heaterfan will not work on high

I have a 1987 Chrysler LeBaron. The A/C/Heater fan works on low and medium
but does not work on high. I went to the dealer and they said it was the
inline resistor for the blower motor. They printed a parts location
diagram for me and it showed a small piece that is in the dashboard
assembly area ( behind the glovebox). But, when I went and picked it up
today it is about 2" by 3" metal with coiled wires! I was expecting an
inline resistor/fuse or something. Before I rip the dash apart, I wanted
to come and ask for advice. It does not seem like this piece would go in
the dashboard area, as it is metal with no covering at all. Did they order
the wrong part? The parts person said that you can go by the drawings, but
what are the drawings for if they are not reliable? Does this unit go in
the engine compartment? If so, can you give me directions as to where it
is located? Any help would be appreciated.

 

Seems to me if the resistor is bad, the low and med wouldn't work,,, if I
remember correctly some of those older cars had a fuse for the high speed
only.. check under the hood for an inline fuse going to the heater motor,,
would be on the passengers side somewhere...

If it is the fuse, change it,, if it blows again, time for a new motor,,, or
don't use the high speed

 

That is possible, despite logic telling us that only the low and
intermediate speeds would fail if it were the resistor. There is a
resistor bypass on the resistor block that provides the high fan speed; if
this fails -- and it can fail in several different ways -- you won't have
high speed. However, this is not as common as a failure in the fan switch
itself.

That is indeed the resistor block. Those coiled wires are the different
lengths of resistive (Nichrome) wire that provide the different levels of
resistance for the different fan speeds. The reason why the resistance
wires are in the airbox is so that the airflow cools them so they don't
burn out.

-Stern

 

wytmagic <> skrev i
diskussionsgruppsmeddelandet:
aboutautos.com...

....
The best thing to do is to measure the voltage after the switch if it is a
traditional switch where the current actually runs through it and it isn't
just a signalling switch telling the "computer" to activate the switch (not
likely on an '87). It should be fairly simple to access the switch and
mesure the voltage.

NOTE: a shortcut could do more damage (even to yourself) - consult a friend
or mechanic if you are unsure!

On several models I've seen (Volvo, Opel, Audi...) you have one incoming +
from the fusebox and one outgoing lead for each fanspeed. These are
connected to the resistor and then to the fan motor. If you know what
connector is for a specific speed, you should measure the voltage between
ground and the pin for the selected speed. There should be +12V (from 10 to
13V depending on your battery's condition) when the fan runs, regardless of
the selected speed, as long as you measure on the pin for the currently
selected speed. If you get +12V on full speed without the blower running,
the fault is in the resistor or the blower motor itself. If you don't, the
switch is broken.

All this assumes the connectors are similar to Opel for instance. Check the
wiring diagram.

Hope this helps.

/Fredrik

 

I had the same problem with my 2000 Sebring, and it really was the resistor,
even though only the high speed did not work.
However, a month later, the new resistor was burned through too. They then
found that the blower motor drew too much power - which killed the resistor.
After replacing the resistor again as well as the blower motor, everything
is fine now. So if you can, you should definitely meassure how much power
your motor is drawing and make sure it is not drawing more than it's
supposed to. Otherwise your new resistor won't last long.

MARK