Dead AC/heater blower, 2000 Cherokee

DougW wrote:
> did pass the time by typing:
> > wrote:
> >> L.W. Hughes III (=DFill) wrote:
> >>> http://www.billhughes.com/blower.pdf
> >>
> > I'm getting closer to getting this thing fixed.
> >
> > The blower itself works fine if I put a jumper across the main relay
> > cavities. The relay itself tests out OK.
> >
> > I found a blown 15A fuse, #25, in the fuse block. I replaced it but it
> > blows as soon as the ignition is turned on. When I put a jumper across
> > it the relay energized (I heard it click) and the blower worked
> > properly.
> >
> > Anyone know why this fuse would keep blowing out?
>
> Fuses blow to prevent the wires from melting and catching fire.

OK, OK, my question was a little too general
>
> So, that means something down the line is pulling way too much
> current. That can be a motor that has shorted windings. Motors
> that fail this way still work but they draw a lot of current.
>
> Disconnect the motor, put in a new fuse, and try again. If it
> doesn't blow it's the motor. If it blows then I dunno, need a
> schematic to help you any further.
>
I just went out and pulled the relay which disconnects the motor as
there is now an open circuit to it. The fuse still blew, instantly - at
lest before I could get the meter on it - once I turned on the
ignition.

--
Thanks,

Aaron

tim bur wrote:
> i just checked in a manual the 25 fuse is for the factory amp for the radio
> it has no connectiopn to the hvac of the jeep
> do u have one and does it work and do u have a aftermarket radio in the
> jeep???
>
I have the basic factory radio w/cassette, it works fine. I have
trouble believing it doesn't connect to the blower as the blower works
properly if I use a plain wire to jump the #25 fuse socket. The #17
fuse, also 15A, cuts my radio out when pulled. Interestingly this fuse
was also blown and replaced when this whole problem started, it's fine
now though...

--
Aaron

You should have disconnected the motor first, that would tell you
if the short is in the motor, where ninety percent are, or in the loom
going to the switch and then motor. As Doug had suggested.
God Bless America, ßill O|||||||O
http://www.billhughes.com/

wrote:
>
> I just went out and pulled the relay which disconnects the motor as
> there is now an open circuit to it. The fuse still blew, instantly - at
> lest before I could get the meter on it - once I turned on the
> ignition.
>
> --
> Thanks,
>
> Aaron

L=2EW. Hughes III (=DFill) wrote:
> You should have disconnected the motor first, that would tell you
> if the short is in the motor, where ninety percent are, or in the loom
> going to the switch and then motor. As Doug had suggested.

Hi Bill, does not pulling out the relay effectively disconnect the
motor since it receives its power through the relay? Perhaps I
completely misunderstand this. I pulled the realy before I put a new
fuse in btw, my writing may not have made that clear.

And time for me to look like a complete fool: What's a loom? (besides a
thing to make fabric with).
--
Thanks,

Aaron

> wrote in message =
oups.com...


>L.W. Hughes III (=DFill) wrote:
>> You should have disconnected the motor first, that would tell you
>> if the short is in the motor, where ninety percent are, or in the =
loom
>> going to the switch and then motor. As Doug had suggested.

>Hi Bill, does not pulling out the relay effectively disconnect the
>motor since it receives its power through the relay? Perhaps I
>completely misunderstand this. I pulled the realy before I put a new
>fuse in btw, my writing may not have made that clear.

Yes, seperate fuse for the motor... fuse #6, 40A.

Your fuse #25 supplies power to:
1) Blower Motor Relay
2) Blend door actuator
3) Shift Lock Solenoid
4) Extended Idle Switch (Police Package)
5) A/C-Heater Control=20
6) Controller, Anti-Lock Brake
7) Controller, Anti-Lock Brake Relay (in PDC)

you can probably eliminate the Anti-lock=20
and the Police Package stuff. I'd start unplugging
stuff and see which one lets it run... you'll need
a good wiring manual for that, I'd spring for a
manual, were I you.
__
Steve
..
=20

Pretend you are replacing the motor, which you will be doing.
God Bless America, ßill O|||||||O
http://www.billhughes.com/

wrote:
>
> Hi Bill, does not pulling out the relay effectively disconnect the
> motor since it receives its power through the relay? Perhaps I
> completely misunderstand this. I pulled the realy before I put a new
> fuse in btw, my writing may not have made that clear.
>
> And time for me to look like a complete fool: What's a loom? (besides a
> thing to make fabric with).
> --
> Thanks,
>
> Aaron

funny thing i looked up fuse 25 with a factory manual on it showwed none of that

Stephen Cowell wrote:

> > wrote in message oups.com...
>
> >L.W. Hughes III (ßill) wrote:
> >> You should have disconnected the motor first, that would tell you
> >> if the short is in the motor, where ninety percent are, or in the loom
> >> going to the switch and then motor. As Doug had suggested.
>
> >Hi Bill, does not pulling out the relay effectively disconnect the
> >motor since it receives its power through the relay? Perhaps I
> >completely misunderstand this. I pulled the realy before I put a new
> >fuse in btw, my writing may not have made that clear.
>
> Yes, seperate fuse for the motor... fuse #6, 40A.
>
> Your fuse #25 supplies power to:
> 1) Blower Motor Relay
> 2) Blend door actuator
> 3) Shift Lock Solenoid
> 4) Extended Idle Switch (Police Package)
> 5) A/C-Heater Control
> 6) Controller, Anti-Lock Brake
> 7) Controller, Anti-Lock Brake Relay (in PDC)
>
> you can probably eliminate the Anti-lock
> and the Police Package stuff. I'd start unplugging
> stuff and see which one lets it run... you'll need
> a good wiring manual for that, I'd spring for a
> manual, were I you.
> __
> Steve
> .
>

"tim bur" > wrote in message =
...
> funny thing i looked up fuse 25 with a factory=20
> manual on it showwed none of that

Are you looking at the 2000 Cherokee FSM?
On page 8W-10-1 the table of contents points
to pg 8W-10-11 for Fuse 25(JB)... looking at Fuse
25 refers to diagrams 8W-12-20 and 8W-12-21..
the first one is left-hand-drive and the second
one is right-hand-drive. Both the same for
our concerns... they only differ in use of=20
junctions.

Fuse 25 in the PDC (Power Distro Center) is
a different fuse... it does the Fog Lights. These
are the ones under the hood, near the battery.
__
Steve
..

im going to look at that

Stephen Cowell wrote:

> "tim bur" > wrote in message ...
> > funny thing i looked up fuse 25 with a factory
> > manual on it showwed none of that
>
> Are you looking at the 2000 Cherokee FSM?
> On page 8W-10-1 the table of contents points
> to pg 8W-10-11 for Fuse 25(JB)... looking at Fuse
> 25 refers to diagrams 8W-12-20 and 8W-12-21..
> the first one is left-hand-drive and the second
> one is right-hand-drive. Both the same for
> our concerns... they only differ in use of
> junctions.
>
> Fuse 25 in the PDC (Power Distro Center) is
> a different fuse... it does the Fog Lights. These
> are the ones under the hood, near the battery.
> __
> Steve
> .