'96 T&C front AC blower not working properly

A few months ago, I wrote about a problem I had with the front AC/Heater
blower on my '96 LXi. I never actually fixed it, just ran a hot wire to
the blower motor and used it that way. The dealer had told me that it
needed a relay but changed that and did nothing. (Very hard to GET to the
relay, by the way!) I had gotten some advice from one of the NG member
concerning a new resistor block and some wiring that goes with it. When I
went to the dealer to get the block $15, I was told I didn't need the
wiring, since the block had not changed. When I got home, noticed that
the plug that goes into the block seemed discolored (from heat, I thot) at
the tan/white wire. I cleaned the connectors, then checked for current at
the plug. I had the ignition turned on and tried EVERY setting on the
HVAC panel. There was NOTHING from ANY of the wires, no matter which one
I checked. I changed the motor (it had begun to rattle from running on
high all the time) and found that it would run WITHOUT the resistor block
connected to anything...in other words, I removed the plug that plugs into
the resistor and the motor still ran, but only on high. And when I plugged
it in, it still ran but only on high. Obviously, there is a problem
SOMEWHERE but since I've changed the relay, resistor block and motor, what
else could it be? Looking at the schematic on page 8W-42-5 of the BIIIG
manual, it appears that the relay must be working otherwise the motor
wouldn't run at all. (I've disconnected the wire I ran directly to the
motor.) But why doesn't it run on any other speed? Is it the HVAC panel?
SOMETHING else? As you can tell, I'm mystified and winter is coming
on...don't want to have to replace anything when it's below zero. HELP!!!
tia...

John

 

Hmm, confusing... If you have 12 volts at the green wire at the blower motor
everyhting is good to that point, test out the black wire coming out of the
blower motor key on (ground) and see if the test lite is lites. If it does,
you are missing a ground, more then likely that ground is open in the
control head.

Glenn Beasley
Chrysler Tech

 

and thru the resistor block
he did state there were discolored

 

Hi John...

Can't offer much but a previous experience, but others here have
been helpful to me as I make the change from a lifetime of GM to
my first Chrysler, so...

Had a Buick wagon, with GM's climate control (temp AND fan speed auto)
Suddenly stopped running on high, either auto or manual. No good in
40 below weather for warming up unattended

Turned out that the high speed was a totally separate feed, in fact
an extra fuse (inline, in the engine compartment near the blower motor)

Suspect that the highest speed drew more current than the wiring to
the speed control switch could handle.

Perhaps Chrysler does the same, and you're suffering the reverse of
what I did? (no 12v through the "normal" channel?)

Take care.

Ken

 

Hmm, confusing... If you have 12 volts at the green wire at the blower
motor everyhting is good to that point, test out the black wire coming out
of the blower motor key on (ground) and see if the test lite is lites. If
it does, you are missing a ground, more then likely that ground is open in
the control head.

Sorry, I have no idea what a "control head" is. And I THINK I have power
to the blue (not green) wire at the motor because the motor runs. As to a
ground, if the motor runs, I would think the black wire (the black wire is
the only wire beside the blue one, going to the motor) must be grounded to
SOMETHING....the problem is that the motor runs even when the resistor
block is disconnected...which seems to mean that it is getting juice from
somewhere OTHER than the resistor. Does that mean it is NOT getting
power thru the HVAC panel but directly from the igntion switch? As I
said, I tested EVERY wire going to the resistor block and NONE of them had
any power going to them. (I tested them by turning on the ignition and
checking EVERY wire in the connector with a volt meter, in EVERY speed at
the HVAC panel) Doesn't that mean that SOMEWHERE there is an open? Maybe
in the HVAC panel or before it? I'm really mystified.

Again, tia.
John