Dodge: 1996 Dodge Grand Caravan LE AC/Heater Blower, Relay and Resistor Block Problems 101

[Updated with NEW information 05-JAN-2004]...

Does your AC/Heater Blower Motor work in high-speed only or possibly some
other speed as well, but NOT all speeds? Does your AC/Heater Blower Motor
not work AT ALL? Or does your AC/Heater Blower Motor seem to "growl, run
slow or stop altogether AFTER running for awhile, though sometimes it
seems by turning it off and waiting awhile the problem resolves itself,
but only temporarily? Does your Blower Motor continue to run after you've
turned off your Caravan? If so, read on...

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Symptom: AC/Heater Blower Motor works in high-speed only or
possibly some other speed as well, but NOT all speeds.

Probable Cause: Bad/Corroded RESISTOR BLOCK.

Solution: Replace Resistor Block.

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Symptom: AC/Blower Blower Motor does not work at all.

Probable Cause: Blown FUSE, bad Blower Motor RELAY and/or bad
Blower MOTOR.

Solution: Inspect fuse, replace if necessary. If the fuse is OK, I
STRONGLY recommend replacing the Blower Motor Relay FIRST - this MIGHT buy
you some time. Personally, I would replace BOTH Blower Motor AND Blower
Motor Relay at the same time because a bad relay can cause a good motor to
behave like a bad one.

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Symtom: AC/Heater Blower Motor seems to "growl, run slow or stop
altogether after running for awhile. Sometimes, it seems that turning it
off and waiting awhile resolves the problem, but only temporarily.

Probable Cause: Blower MOTOR brushes worn, bad bearing in Blower
MOTOR, and/or Blower Motor RELAY contacts are burned or pitted.

Solution: Replace Blower Motor Relay, then Blower Motor, if
necessary, preferably, both the Blower Motor Relay and Blower Motor at the
SAME time.

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Symtom: AC/Heater Blower Motor continues to run after the engine is
turned off and the key is removed from the ignition.

Probable Cause: Blower Motor RELAY contacts are "welded" in the
closed position and refuse to cut power to the Blower Motor.

Solution: Replace Blower Motor Relay.

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PART NUMBERS, MANUFACTURERS & POINT of PURCHASE (more coming)

Blower Motor Relay:
OEM=4638094; GP Sorensen=MR76; AC Delco=15-8426; Hella=1410045; Niehoff
Ignition=RL35301
(prices I've seen vary between $8 and $13USD - the OEM price quoted by my
Dodge dealer was $71USD which includes 6% CT state sales tax)

Blower Motor:
OEM=(go to your dealer); AC Delco=15-80104; Siemens=PM3324X-12V-02345;
FactoryAir=35283
(prices I've seen vary from $45 and $60USD, the full OEM unit is between
$130-$175USD - the OEM price quoted by my Dodge dealer was $137USD which
includes 6% CT state sales tax)

Resistor Block:
OEM=(go to your dealer)
(the price quoted by my Dodge dealer was $16USD which includes 6% CT state
sales tax)

Stores/Places to Get Parts:
Advance Auto Parts; Auto Zone; CarQuest; Levine Automotive (in Connecticut
USA)

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Anyone who has ever tried to troubleshoot and resolve an AC/Heater blower
motor, relay and/or resistor block problem has probably shortened their
lives by years. Well, I know *I* have. However, I am NOW sitting in front
of my computer... after giving blood and sweat to the task and
*successfully* resolving ALL issues related to my 1996 Dodge Grand Caravan
LE's AC/Heater Blower problems. Print out this puppy before you attempt to
troubleshoot your own problem...

I apologize for the length of this "dissertation," but I hope it covers
and/or incites others to cover most common AC/Heater Blower Motor
problems.

Step #1 - DISCONNECT the NEGATIVE battery cable from the
battery. If you FAIL to do this, you risk shorting out a number of
components that are EXPENSIVE to replace. You might also accidentally
deploy either or both of your AIRBAGs which are HIDEOUSLY expensive to
replace - not to mention extremely DANGEROUS with your head so
close to these explosive devices!

Depending on the SYMPTOMS of your Caravan AC/Heater Blower Motor problem,
you may wind up performing more than one problem resolution. Read through
ALL of this BEFORE you decide what YOUR Step #2, #3 and so forth will be.


The first thing to remember is that their are at least FOUR main
user-serviceable components in the the AC/Heater Blower system:

1.) 30AMP FUSE - located in the Power Distribution Center
(PDC) which, for the '96 Grand Caravan, is the third 30amp fuse from the
right. The inside cover of the PDC for your Caravan will show you
*exactly* where your Blower Motor Fuse is located. Carefully remove this
fuse (pliers are OK if you are *careful*) and look at it - if it's bad,
the little "loopy" conductor will be burned out - if so, replace the
fuse.

2.) RESISTOR BLOCK - located under the hood, passenger-side,
above and slightly to the right of the shock tower. You do NOT have to pull
this out of the firewall to inspect it. Remove the glovebox/door. You can
see the Resistor Block poking through, high up, on the firewall by peering
through the hole where the glovebox/door used to be. You will recognize the
Resistor Block by several coiled wires (looks like a heater element)
contained in a rectantagular arrangement about 3 inches wide and 1 inch
high. If you see ANY rust on these coils, I suggest you REPLACE it.
Removal is a PITA, but accomplished with the hood up and pulling it out of
the firewall. Keep some BandAids handly. I gave blood; you might too.

@#$%&! Dodge Engineers!

3.) BLOWER MOTOR RELAY - I have considered strangling the
Dodge engineer who "designed" this device to reside in its installed
location. This is by far THE most difficult component to replace, but it
is also among the least expensive ($8-$13)... and doing so can resolve one
or more of a number of problems. Get your tools out and allow between 1-2
hours for disassembly, replacement and reassembly. No kidding. You'll need
a Phillips screwdriver, a 10mm socket and ratchet with a 6-to-8-inch
extension.

a.) Remove the plastic facia below the steering column (4 or 5
Philips-head screws).

b.) Disconnect the parking brake cable from the facia (make a note about
how the cable is attached - you have to lift the cable up and slide it
sideways/outward to remove it from the facia).

c.) Remove the stamped-steel shroud beneath the steering column - it's
(the one previously covered by the facia removed in Step b.) held on by
about (12) 10mm hex-head screws - make a note of the screw types and their
locations, there are 2 types of screws.

d.) Disconnect the hood release latch.

e.) Disconnect the computer diagnostics connector from the U-Channel
crossmember.

f.) Uninstall the U-Channel crossmember - removing several 10mm hex-head
screws get this job done. Trust me, you WILL need the extra clearance to
get at the Blower Motor Relay later.

g.) Remove the Junction Box cover and unbolt the Junction Box (under the
dash, driver's side, it contains relays and fuses, it also has the Body
Control Module attached to its back) - there are three 10mm screws, each
about 3 inches long that must be removed.

h.) GENTLY pull the Junction Box as far forward as possible. Behind the
Junction Box, up high and attached to a clip on the firewall, is the
Blower Motor Relay. (Now you know why I have considered strangling the
"engineer" for this flash of brilliance). You will recognize the Blower
Motor Relay as a "black box" with four wires (blue, green, orange/black
and black). It's size is about 1"x1"x2".

i.) Carefully unclip/unfasten the Blower Motor Relay with wires attached
from the firewall and GENTLY pull downward as far as possible. You will
notice that a plastic depression clip holds the wired connector to the
Blower Motor Relay... depress it and carefully pull the Blower Motor Relay
out of its socket.

j.) You will notice that the OEM part has 4 prongs and your replacement
part probably has 5; don't worry, the GP Sorensen, AC Delco and Hella
parts work fine - I tested ALL of them to make absolutely sure. Plug your
replacement part into the Blower Motor Relay socket.

k.) Wrap a piece of electrical tape completely around the relay and its
socket - this prevents dirt and dust from getting into and around the
contact points and also makes it less likely that the relay will somehow
work its way out of the socket.

l.) Unless you are certified masochistic, do NOT attempt to position the
Blower Motor Relay anywhere NEAR its original location. The special
housing that came with the OEM relay is probably NOT part of the
replacement part anyway (and do NOT attempt to reuse ANY piece of the old
part). Keep the relay in view while you reassemble your Caravan and
tuck/tape/bind it in any way you see fit after the reassembly is complete.
That's what I did. Screw Dodge engineers. Anybody feel like storming
Chrysler with torches and pitchforks by now?

Hey, pat yourself on the back - you're halfway home on this one. Get a
beer. Or a glass of wine. Or whatever. But only ONE. You still need to
remain focused.

m.) Starting with Step h., - reassembly is the reverse of disassembly.

NOTE: After you have reassembled the dash, your new Blower Motor Relay
should be visible underneath and behind the Junction Box/BCM... make sure
it is out of the way of your feet when you drive. At any rate, it will now
be a whole lot easier to replace this relay agian, should you ever need to
do so.

4.) BLOWER MOTOR - located under/behind the glovebox/door.
If the symptoms of your AC/heater blower problem indicates a motor
replacement, take heart in knowing this is not THE most difficult task to
finish. Still, I write about this because I continue to be horrified by
the prices of so-called replacement motor parts - between $130-$175USD
from dealers. Gadzooks. Fact is, the motor, only the motor, cost me
$45USD (about 1/3 the cost of the OEM unit which also includes the motor
housing and fan/cage), but requires a certain amount of "handyman savvy."

a.) Remove the glovebox/door.

b.) Remove the Blower Moter cover (four screws).

c.) Remove the Blower Motor ASSEMBLY (motor, fan/cage fan and fixture -
three screws). If you are NOT using the expensive OEM part and plan to
reuse the motor jousing and fan/cage, BE CAREFUL not to damage the
fan/cage - it is "delicate."

If you bought a complete and expensive OEM replacement motor/fan, stop
here. All you need to do is reinstall it. However, if you did what I did
and bought ONLY the motor for about 1/3 the cost (and did NOT break the
fan/cage when removing the old motor!), proceed to Step c.

d.) FIRST, you must remove the old Blower Motor from its housing. There
are 2 screws and 3 rubber bushings that center and hold the old motor in
this housing. This is a little tricky, but it CAN be done.

e.) Remove the two screws from the bottom of the motor housing and, using
a small flat-bladed screwdriver, carefully depress each of three rubber
bushings to release the motor from its housing.

NOTE: Be EXTREMELY careful NOT to damage the fan/cage in ANY way... if you
do, it's GAME OVER and you MUST buy the expensive replacement unit from
your dealer!

f.) It IS possible to remove the fan/cage from the old motor for
replacement on the new motor, but it requires VERY careful planning and
execution. First, put the old Blower Motor tightly in a VISE, with the
fan/cage upright (not tight enough to crush the housing, but tight enough
to bang on it with a hammer [described below]).

g.) Lay a hacksaw blade flat on the top of the fan/cage, with teeth facing
the motor spindle. Carefully saw sideways through the top of the plastic
shaft on one side. Place the hacksaw blade on the other side (180 degrees)
of the plastic shaft and saw through the plastic shaft to the metal motor
spindle again. You should now have 2 notches on either side of the spindle
(opposite sides), through the plastic shaft.

h.) Using a hammer and POINTED punch, score a dimple into the end of the
metal motor spindle.

i.) Using a hub puller, place the blades of the puller into the scores of
the plastic shaft you created in Step f. Use a C-clamp to push the grips
into these scores (a fair amount, but not too much pressure).

j.) Rotate the hub puller clock-wise, centering the hub puller pin into
the dimple you created in step f. Rotate the hub puller to gently lift the
fan/cage about 1/2 inch UPWARD on the motor spindle.

k.) Remove the C-Clamp and hub puller. You should now be able to carefully
and EVENLY lift from the bottom the fan/cage up and off the mottor spindle.
CAREFUL!

l.) The replacement motor I bought was a Unimotor for the Dodge Grand
Caravan from Carquest. I had to wrap this motor with a foam buffer strip
(came with the motor) to properly fit in the stock OEM housing. Once done,
I carefully pressed the fan cage back onto the new motor spindle. I did
notice that the motor spindle length was about 1/8" longer than the old
OEM part, so the motor spindle protruded by that same amount beyond the
fan/cage shaft. As a precaution, I mixed up a little epoxy and dabbed the
end of the spindle so the fan/cage DEFINITELY would not slide on the
spindle.

m.) You MAY have to modify the OEM motor housing in order to get the motor
to seat FLUSH in housing - I had to carefully cut the center piece out of
the end of the motor housing so I could screw the new motor into the
bottom of the housing. Make SURE the motor sits FLUSH in the bottom of the
motor housing!

n.) Reinstallation is the reverse of installation, beginning with Step e.

I invite, urge and encourage anyone and EVERYONE to jump on this thread to
add, correct, clarify, whatever on this subject... I think WE do a better
job than Chilton, Haynes and Chrysler!

I figure I saved close to $200 in parts costs and another $300 in labor
charges by doing all of this myself. Of course, it took me an entire DAY
to work out all of this and get the job done, but maybe next time I
will be finished in 3 hours, or less!

Cheers!