Dead AC/heater blower, 2000 Cherokee

Hello all, I have a 2000 Cherokee. My heater/AC blower won't turn on. I had a dead battery and a blown fused wire (idiot with a jump pack). A
battery shop replaced the battery and wire but I picked it up after hours and when I tried to turn on the heat - no fan. The radio was dead too, I fixed that by replacing a blown fuse. The shop is pretty much no help and two hours away, all they say is "bring it in", yeah right, drive four hours for a $10 part).
The fuse marked "blower" 40AMP, in the power distribution center is fine. A friend suggested it may be a relay, the question is which one and where and how would I test it (I have a multimeter, just no idea how to test a relay). I realize I could also have a fried wire somewhere but hoping for the relay. Any other thoughts?
Thanks,
Aaron
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http://www.billhughes.com/blower.pdf God Bless America, ill O|||||||O mailto: snipped-for-privacy@aol.com
snipped-for-privacy@msn.com wrote:

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L.W. Hughes III (ill) wrote:

Thanks, just what I needed. The relay was indeed blown with some visible scorching on 87 and 87a. Unfortunatly replacing the relay did not fix the problem. I tried the "relay circuit test" as outlined in the manual above but am a bit confused. It says there should be voltage to cavity 30 at all times, there is not. There is voltage to cavity 87 which the guide seems to say there should not be. Do I have a fried wire here?
Thanks,
Aaron
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snipped-for-privacy@msn.com wrote:

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?
Thanks,
Aaron
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snipped-for-privacy@msn.com did pass the time by typing:

Fuses blow to prevent the wires from melting and catching fire.
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.
--
DougW



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Ditto. God Bless America, ill O|||||||O mailto: snipped-for-privacy@aol.com http://www.billhughes.com /
DougW wrote:

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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???
DougW wrote:

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tim bur wrote:

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
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DougW wrote:

OK, OK, my question was a little too general ;)

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
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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, ill O|||||||O mailto: snipped-for-privacy@aol.com http://www.billhughes.com /
snipped-for-privacy@msn.com wrote:

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L.W. Hughes III (ill) 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
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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 .
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funny thing i looked up fuse 25 with a factory manual on it showwed none of that
Stephen Cowell wrote:

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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 .
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im going to look at that
Stephen Cowell wrote:

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Pretend you are replacing the motor, which you will be doing. God Bless America, ill O|||||||O mailto: snipped-for-privacy@aol.com http://www.billhughes.com /
snipped-for-privacy@msn.com wrote:

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a short what is the position number for the fuse
snipped-for-privacy@msn.com wrote:

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tim bur wrote:

#25, right above the two airbag fuses (only 2 that are labeled - Yes, I know there should be a label on the panel cover but there is not).
Thanks,
Aaron
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look inthe owners manual and you will find other fuses under the dash it's best to use a test lite to test the fuses a hiarline crack in the fuse may not be seen
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