Help, A/C blower motor won't turn off
09-25-2003, 02:28 PM
#21
Guest
Posts: n/a
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
> $800, which I was told was actually not too bad, but now for about the
> same price I get to turn a fan off. Go figure.
I actually bought the extended warranty [from a competitor yet]
on a used ZJ on the recommendation of the service manager
at the Jeep dealer [the ZJ itself was bought elsewhere] when
he told me how much it typically costs to make repairs on
the air conditioner, seat controls, etc. compared to the
more reasonable prices for running gear repairs. Worse than
a darned cadillac.
> You guys are a wealth of information, thanks a lot. Oh, my Jeep does
> have ATC, I forgot to state that. Unfortunately, I tried the various
> suggestions and I still have the problem.
>
> Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message news:<JBpcb.570779$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
> $800, which I was told was actually not too bad, but now for about the
> same price I get to turn a fan off. Go figure.
I actually bought the extended warranty [from a competitor yet]
on a used ZJ on the recommendation of the service manager
at the Jeep dealer [the ZJ itself was bought elsewhere] when
he told me how much it typically costs to make repairs on
the air conditioner, seat controls, etc. compared to the
more reasonable prices for running gear repairs. Worse than
a darned cadillac.
09-25-2003, 07:49 PM
#22
Guest
Posts: n/a
Re: Help, A/C blower motor won't turn off
"Lon Stowell" <Lawn.Stowell@Komkast.net> wrote in message
news:HtGcb.429932$Oz4.228043@rwcrnsc54...
.....
> Worse than
> a darned cadillac.
Having messed with a '93 Taurus with ATC, I'll never
own one again. Simple switch and resistor pack for me.
On topic, I'll bet it's the motor speed feedback, since
it did slow down during test and popped that code.
I wonder if that's replaceable, without changing the blower.
__
Steve
..
09-25-2003, 07:49 PM
#23
Guest
Posts: n/a
Re: Help, A/C blower motor won't turn off
"Lon Stowell" <Lawn.Stowell@Komkast.net> wrote in message
news:HtGcb.429932$Oz4.228043@rwcrnsc54...
.....
> Worse than
> a darned cadillac.
Having messed with a '93 Taurus with ATC, I'll never
own one again. Simple switch and resistor pack for me.
On topic, I'll bet it's the motor speed feedback, since
it did slow down during test and popped that code.
I wonder if that's replaceable, without changing the blower.
__
Steve
..
09-26-2003, 04:31 PM
#24
Guest
Posts: n/a
Re: Help, A/C blower motor won't turn off
Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message news:<HtGcb.429932$Oz4.228043@rwcrnsc54>...
> 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.
After considering all the alternatives suggested on this board, I went
to a different mechanic (factory guy) and was able to talk with him
more intelligently about the problem. He diagnosed it as a bad blower
motor resistor, part #4720046. He replaced it for $127.05 parts and
$77 labor. And I thought only Uncle Sam would pay $127 for a
resistor. Imagine if it would have been a capacitor. Better than the
$700 the other guy wanted to charge to replace the entire HVAC control
head.
Thanks again for all your advice.
> 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.
After considering all the alternatives suggested on this board, I went
to a different mechanic (factory guy) and was able to talk with him
more intelligently about the problem. He diagnosed it as a bad blower
motor resistor, part #4720046. He replaced it for $127.05 parts and
$77 labor. And I thought only Uncle Sam would pay $127 for a
resistor. Imagine if it would have been a capacitor. Better than the
$700 the other guy wanted to charge to replace the entire HVAC control
head.
Thanks again for all your advice.
09-26-2003, 04:31 PM
#25
Guest
Posts: n/a
Re: Help, A/C blower motor won't turn off
Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message news:<HtGcb.429932$Oz4.228043@rwcrnsc54>...
> 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.
After considering all the alternatives suggested on this board, I went
to a different mechanic (factory guy) and was able to talk with him
more intelligently about the problem. He diagnosed it as a bad blower
motor resistor, part #4720046. He replaced it for $127.05 parts and
$77 labor. And I thought only Uncle Sam would pay $127 for a
resistor. Imagine if it would have been a capacitor. Better than the
$700 the other guy wanted to charge to replace the entire HVAC control
head.
Thanks again for all your advice.
> 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.
After considering all the alternatives suggested on this board, I went
to a different mechanic (factory guy) and was able to talk with him
more intelligently about the problem. He diagnosed it as a bad blower
motor resistor, part #4720046. He replaced it for $127.05 parts and
$77 labor. And I thought only Uncle Sam would pay $127 for a
resistor. Imagine if it would have been a capacitor. Better than the
$700 the other guy wanted to charge to replace the entire HVAC control
head.
Thanks again for all your advice.
09-26-2003, 05:04 PM
#26
Guest
Posts: n/a
Re: Help, A/C blower motor won't turn off
Approximately 9/26/03 13:31, np6 uttered for posterity:
> Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message news:<HtGcb.429932$Oz4.228043@rwcrnsc54>...
>
>> 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.
>
> After considering all the alternatives suggested on this board, I went
> to a different mechanic (factory guy) and was able to talk with him
> more intelligently about the problem. He diagnosed it as a bad blower
> motor resistor, part #4720046. He replaced it for $127.05 parts and
> $77 labor. And I thought only Uncle Sam would pay $127 for a
> resistor. Imagine if it would have been a capacitor. Better than the
> $700 the other guy wanted to charge to replace the entire HVAC control
> head.
Parts is expensive, but on the ATC system, I'd be very surprised
if that motor resistor pack wasn't in the speed feedback chain
pretty much as the diags showed.
> Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message news:<HtGcb.429932$Oz4.228043@rwcrnsc54>...
>
>> 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.
>
> After considering all the alternatives suggested on this board, I went
> to a different mechanic (factory guy) and was able to talk with him
> more intelligently about the problem. He diagnosed it as a bad blower
> motor resistor, part #4720046. He replaced it for $127.05 parts and
> $77 labor. And I thought only Uncle Sam would pay $127 for a
> resistor. Imagine if it would have been a capacitor. Better than the
> $700 the other guy wanted to charge to replace the entire HVAC control
> head.
Parts is expensive, but on the ATC system, I'd be very surprised
if that motor resistor pack wasn't in the speed feedback chain
pretty much as the diags showed.
09-26-2003, 05:04 PM
#27
Guest
Posts: n/a
Re: Help, A/C blower motor won't turn off
Approximately 9/26/03 13:31, np6 uttered for posterity:
> Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message news:<HtGcb.429932$Oz4.228043@rwcrnsc54>...
>
>> 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.
>
> After considering all the alternatives suggested on this board, I went
> to a different mechanic (factory guy) and was able to talk with him
> more intelligently about the problem. He diagnosed it as a bad blower
> motor resistor, part #4720046. He replaced it for $127.05 parts and
> $77 labor. And I thought only Uncle Sam would pay $127 for a
> resistor. Imagine if it would have been a capacitor. Better than the
> $700 the other guy wanted to charge to replace the entire HVAC control
> head.
Parts is expensive, but on the ATC system, I'd be very surprised
if that motor resistor pack wasn't in the speed feedback chain
pretty much as the diags showed.
> Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message news:<HtGcb.429932$Oz4.228043@rwcrnsc54>...
>
>> 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.
>
> After considering all the alternatives suggested on this board, I went
> to a different mechanic (factory guy) and was able to talk with him
> more intelligently about the problem. He diagnosed it as a bad blower
> motor resistor, part #4720046. He replaced it for $127.05 parts and
> $77 labor. And I thought only Uncle Sam would pay $127 for a
> resistor. Imagine if it would have been a capacitor. Better than the
> $700 the other guy wanted to charge to replace the entire HVAC control
> head.
Parts is expensive, but on the ATC system, I'd be very surprised
if that motor resistor pack wasn't in the speed feedback chain
pretty much as the diags showed.
09-26-2003, 09:23 PM
#28
Guest
Posts: n/a
Re: Help, A/C blower motor won't turn off
"Lon Stowell" <Lawn.Stowell@Komkast.net> wrote in message
news:QR1db.155318$mp.84103@rwcrnsc51.ops.asp.att.n et...
> Approximately 9/26/03 13:31, np6 uttered for posterity:
> > Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message
news:<HtGcb.429932$Oz4.228043@rwcrnsc54>...
> >
> >> 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.
> >
> > After considering all the alternatives suggested on this board, I went
> > to a different mechanic (factory guy) and was able to talk with him
> > more intelligently about the problem. He diagnosed it as a bad blower
> > motor resistor, part #4720046. He replaced it for $127.05 parts and
> > $77 labor. And I thought only Uncle Sam would pay $127 for a
> > resistor. Imagine if it would have been a capacitor. Better than the
> > $700 the other guy wanted to charge to replace the entire HVAC control
> > head.
>
> Parts is expensive, but on the ATC system, I'd be very surprised
> if that motor resistor pack wasn't in the speed feedback chain
> pretty much as the diags showed.
With continuously variable speed blower, it's not a simple
resistor pack... more like a speed controller, like the robots
on Robot Wars use. $127 sounds a *lot* more like a
speed controller module than nichrome wire coils and
a thermal fuse. That's what my '93 Taurus LX (POS)
used... now an obsolete part.
__
Steve
..
09-26-2003, 09:23 PM
#29
Guest
Posts: n/a
Re: Help, A/C blower motor won't turn off
"Lon Stowell" <Lawn.Stowell@Komkast.net> wrote in message
news:QR1db.155318$mp.84103@rwcrnsc51.ops.asp.att.n et...
> Approximately 9/26/03 13:31, np6 uttered for posterity:
> > Lon Stowell <Lawn.Stowell@Komkast.net> wrote in message
news:<HtGcb.429932$Oz4.228043@rwcrnsc54>...
> >
> >> 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.
> >
> > After considering all the alternatives suggested on this board, I went
> > to a different mechanic (factory guy) and was able to talk with him
> > more intelligently about the problem. He diagnosed it as a bad blower
> > motor resistor, part #4720046. He replaced it for $127.05 parts and
> > $77 labor. And I thought only Uncle Sam would pay $127 for a
> > resistor. Imagine if it would have been a capacitor. Better than the
> > $700 the other guy wanted to charge to replace the entire HVAC control
> > head.
>
> Parts is expensive, but on the ATC system, I'd be very surprised
> if that motor resistor pack wasn't in the speed feedback chain
> pretty much as the diags showed.
With continuously variable speed blower, it's not a simple
resistor pack... more like a speed controller, like the robots
on Robot Wars use. $127 sounds a *lot* more like a
speed controller module than nichrome wire coils and
a thermal fuse. That's what my '93 Taurus LX (POS)
used... now an obsolete part.
__
Steve
..
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