Re: Help, A/C blower motor won't turn off
 

http://www.----------.com/blower.pdf
God Bless America, ßill O|||||||O
mailto:--------------------

np6 wrote:
>
> I have a strange problem in my 94 Grand Cherokee Limited. The other
> day I turned the car off and the a/c blower motor (fan) kept running
> even after I took the key out. I had to pull the fuse to shut it off.
> The a/c and heater seem to work ok, it's just that the fan won't turn
> off. I took it to a local mechanic who said I need a new HVAC control
> head. The dealer has to order it, and it costs $700! Can it really
> be that big of a problem to fix a blower motor that won't shut off?
> I'm now popping the hood and putting the fuse in before I drive, then
> pulling the fuse when I'm done. For $700, I'm thinking of building
> some kind of switch that runs from the fuse to outside the hood so I
> don't have to pop the hood. Any ideas?

Re: Help, A/C blower motor won't turn off
 

L.W. (ßill) ------ III did pass the time by typing:
> http://www.----------.com/blower.pdf

That's the relay.. It shows in my service book like
a relay on the control head but the numbering
indicates a much larger relay that would be mounted
to a board. The numbering in that diagram matches
and I'm fairly sure the guts didn't change from
93-95. Only some minor things like 4wheel disc brakes.

Re: Help, A/C blower motor won't turn off
 

L.W. (ßill) ------ III did pass the time by typing:
> http://www.----------.com/blower.pdf

That's the relay.. It shows in my service book like
a relay on the control head but the numbering
indicates a much larger relay that would be mounted
to a board. The numbering in that diagram matches
and I'm fairly sure the guts didn't change from
93-95. Only some minor things like 4wheel disc brakes.

Re: Help, A/C blower motor won't turn off
 

That's my guess.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/


DougW wrote:
>
> That's the relay.. It shows in my service book like
> a relay on the control head but the numbering
> indicates a much larger relay that would be mounted
> to a board. The numbering in that diagram matches
> and I'm fairly sure the guts didn't change from
> 93-95. Only some minor things like 4wheel disc brakes.

Re: Help, A/C blower motor won't turn off
 

That's my guess.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/


DougW wrote:
>
> That's the relay.. It shows in my service book like
> a relay on the control head but the numbering
> indicates a much larger relay that would be mounted
> to a board. The numbering in that diagram matches
> and I'm fairly sure the guts didn't change from
> 93-95. Only some minor things like 4wheel disc brakes.

Re: Help, A/C blower motor won't turn off
 

Approximately 9/24/03 18:08, DougW uttered for posterity:

> L.W. (ßill) ------ III did pass the time by typing:
>> http://www.----------.com/blower.pdf
>
> That's the relay.. It shows in my service book like
> a relay on the control head but the numbering
> indicates a much larger relay that would be mounted
> to a board. The numbering in that diagram matches
> and I'm fairly sure the guts didn't change from
> 93-95. Only some minor things like 4wheel disc brakes.
>
>

Bill's picture exactly matches where the FSM says
it is.... so swap that sucker. From the wiring
diagram, if you can get your hand in there it
should be possible to just pull the sucker to
test, since if you have ATC [which we forgot to
ask] the only thing that relay does is kick in
high speed, aka full battery voltage.

Re: Help, A/C blower motor won't turn off
 

Approximately 9/24/03 18:08, DougW uttered for posterity:

> L.W. (ßill) ------ III did pass the time by typing:
>> http://www.----------.com/blower.pdf
>
> That's the relay.. It shows in my service book like
> a relay on the control head but the numbering
> indicates a much larger relay that would be mounted
> to a board. The numbering in that diagram matches
> and I'm fairly sure the guts didn't change from
> 93-95. Only some minor things like 4wheel disc brakes.
>
>

Bill's picture exactly matches where the FSM says
it is.... so swap that sucker. From the wiring
diagram, if you can get your hand in there it
should be possible to just pull the sucker to
test, since if you have ATC [which we forgot to
ask] the only thing that relay does is kick in
high speed, aka full battery voltage.

Re: Help, A/C blower motor won't turn off
 

You guys are a wealth of information, thanks a lot. Oh, my Jeep does
have ATC, I forgot to state that. Unfortunately, I tried the various
suggestions and I still have the problem.

Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message news:<JBpcb.570779$o%2.256178@sccrnsc02>...

>
> The blower motor is controlled by the ATC controls with
> speed feedback. You may want to disconnect the battery
> as it resets the control completely. This *could* be
> as trivial as the high speed relay.

I disconnected the battery and reconnected it, but the problem is
still there. I also tried to find the relay and hit it lightly. Not
sure I actually found it, but nothing I hit made any difference.

> With the fuse in, turn it on, then turn the motor off.
> Then pull the A/C fault codes.

I followed your detailed instructions (thanks) and this is what I got:
Code 08 and 48.

I then did the output tests you mentioned and this is what I got:

Test number 01 display 11
Test number 02, display 28
Test number 03, display 28
Test number 04, display 00

I then pushed the RECIRC button and the fan did speed up/down.

This is greek to me, but maybe it will tell you something.

I did see a fat juicy red wire going into the blower motor, just under
the glove compartment. I'm tempted to cut that and put an online
switch there, but when I mentioned this to the mechanic he said I
could produce a voltage spike that might screw up the computer that
controls everything and costs $2000. So, I'm hesitant to do anything
there but still thinking about putting a switch in place of the fuse
under the hood, that might be a safer thing to do.

I just hate paying $700 to turn off a #%@^$ fan. Just last month I
took it in to repair the CV joints, and they replaced both axles for
$800, which I was told was actually not too bad, but now for about the
same price I get to turn a fan off. Go figure.

Re: Help, A/C blower motor won't turn off
 

You guys are a wealth of information, thanks a lot. Oh, my Jeep does
have ATC, I forgot to state that. Unfortunately, I tried the various
suggestions and I still have the problem.

Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message news:<JBpcb.570779$o%2.256178@sccrnsc02>...

>
> The blower motor is controlled by the ATC controls with
> speed feedback. You may want to disconnect the battery
> as it resets the control completely. This *could* be
> as trivial as the high speed relay.

I disconnected the battery and reconnected it, but the problem is
still there. I also tried to find the relay and hit it lightly. Not
sure I actually found it, but nothing I hit made any difference.

> With the fuse in, turn it on, then turn the motor off.
> Then pull the A/C fault codes.

I followed your detailed instructions (thanks) and this is what I got:
Code 08 and 48.

I then did the output tests you mentioned and this is what I got:

Test number 01 display 11
Test number 02, display 28
Test number 03, display 28
Test number 04, display 00

I then pushed the RECIRC button and the fan did speed up/down.

This is greek to me, but maybe it will tell you something.

I did see a fat juicy red wire going into the blower motor, just under
the glove compartment. I'm tempted to cut that and put an online
switch there, but when I mentioned this to the mechanic he said I
could produce a voltage spike that might screw up the computer that
controls everything and costs $2000. So, I'm hesitant to do anything
there but still thinking about putting a switch in place of the fuse
under the hood, that might be a safer thing to do.

I just hate paying $700 to turn off a #%@^$ fan. Just last month I
took it in to repair the CV joints, and they replaced both axles for
$800, which I was told was actually not too bad, but now for about the
same price I get to turn a fan off. Go figure.

Re: Help, A/C blower motor won't turn off
 

Approximately 9/25/03 08:01, np6 uttered for posterity:

> You guys are a wealth of information, thanks a lot. Oh, my Jeep does
> have ATC, I forgot to state that. Unfortunately, I tried the various
> suggestions and I still have the problem.
>
> Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message news:<JBpcb.570779$o%2.256178@sccrnsc02>...
>
>>
>> The blower motor is controlled by the ATC controls with
>> speed feedback. You may want to disconnect the battery
>> as it resets the control completely. This *could* be
>> as trivial as the high speed relay.
>
> I disconnected the battery and reconnected it, but the problem is
> still there. I also tried to find the relay and hit it lightly. Not
> sure I actually found it, but nothing I hit made any difference.
>
>> With the fuse in, turn it on, then turn the motor off.
>> Then pull the A/C fault codes.
>
> I followed your detailed instructions (thanks) and this is what I got:
> Code 08 and 48.

08 means the feedback from the motor is too high which is wierd
unless there is a typo in my FSM, as it claims 48 means that at
some time in the past it was too low.

Purely a WAG, but if that relay was shorted or the power control
module was fried, I would expect solid fan speed and probably
an error because the commanded speed wouldn't match the actual
speed. Real jeep mechanics feel free to jump in any time here...

I'd pull the relay if you can...

>
> I then did the output tests you mentioned and this is what I got:
>
> Test number 01 display 11
> Test number 02, display 28
> Test number 03, display 28
> Test number 04, display 00 [it thinks the drive to the high
speed blower relay is off...]


>
> I then pushed the RECIRC button and the fan did speed up/down.

Hmmm. So whatever is wrong is such that the fan can be
controlled. To me this would eliminate the relay, but
I'd still pull it just because I am such a sceptical cuss.

And it looks like the power controller may indeed be able
to change the amount of battery voltage available to the
motor.... unless it is interacting with the high speed
relay which is easily checked by yanking the relay.

If the fan speed is still changeable, either the power
control module has a blown position in it [dunno likelihood]
or the output of the ATC module is tweaked, or the motor
itself has a bad feedback pickup, causing the ATC to freak
out.

To narrow it down, the only way I can see is to get under
there and check the voltages at a coupla points from the
ATC to the motor and back... after pulling the relay of course.

> I just hate paying $700 to turn off a #%@^$ fan. Just last month I
> took it in to repair the CV joints, and they replaced both axles for
> $800, which I was told was actually not too bad, but now for about the
> same price I get to turn a fan off. Go figure.

I actually bought the extended warranty [from a competitor yet]
on a used ZJ on the recommendation of the service manager
at the Jeep dealer [the ZJ itself was bought elsewhere] when
he told me how much it typically costs to make repairs on
the air conditioner, seat controls, etc. compared to the
more reasonable prices for running gear repairs. Worse than
a darned cadillac.