98 Cherokee Sport...BLOWER ISSUES

Tried the Airbag/Horn Pad....didn't change anything....unplugged clock spring...no change....unplugged air bag control module...no change....with Fuse 26 of JB removed, the blower and draw are gone....but for the airbag system to work...I need that fuse back in there....also the horn continually blows if there is a Fuse in 21 of JB...and even with Fuse 21 Removed...the Horn Relay clicks every time you unplug or plug it in....so far I haven't seen all that much as far as wiring goes that has anything to do with airbag...looks like Fuse 26 and Fuse 27 of JB....27 doesn't do anything when unplugged or plugged in...but 26 DOES!!!...Leaning NOW towards something to do with why horn is staying on as where my problem is now....Thoughts again??
 
Messed with the XJ again half the night....I found constant power at the Air Bag Control Module wiring (Light Green wire with Yellow Stripe)with it UNPLUGGED from the module....went to JB and found the harness that plugs in there and disconnected it...no constant power after that at the Module harness...pulled on harness to see where it went...it goes into main big harness that goes through firewall....not sure where it goes once it goes in there...as Chrysler wiring harness diagrams are not the most friendly to decipher...that's where I am now...gotta figure out why that wire is getting constant power...could possibly be why the horn won't stop blowing when relay is installed too...it may be getting constant power through the same area....I welcome your ideas!!!
 
Concerenng the horn:

The horn relay control coil is constantly hot off the battery bus through fuse 4 in the PDC, and is looking for a ground to activate the relay. The ground can be provided through the horn switch in the airbag, via the clockspring, or through the Remote Keyless Entry (RKE) module (lock/panic feature on your FOB).

You've replaced the horn switch and isolated the clockspring by disconnecting it at the clockspring and the horn still operates (was provided a ground). Short of suspecting a short to ground in the horn switch circuit, I would turn my attention to the RKE module., The RKE receiver module is located in the overhead console (if you have one) or in the mini-dome light housing. In either case, the SKE receiver should be accessed and disconnected to see if the horn stops operating.
 
That is unplugged as well (I have the headliner out at the moment)...No air bag/horn button or overhead light is plugged in and it still blows constantly with the relay and fuse in place....

The air bag module has the green with yellow stripe wire (That is supposed to be keyed only I believe) having constant power...if it's unplugged from the JB...then I lose the constant power....Any idea what the path is for that wire from the JB to the Air Bag Control Module?? Is there any kind of junction or module inline with that wire?? I don't want to hack wires if at all possible...Awaiting reply..LOL
 
That is unplugged as well (I have the headliner out at the moment)...No air bag/horn button or overhead light is plugged in and it still blows constantly with the relay and fuse in place....

The air bag module has the green with yellow stripe wire (That is supposed to be keyed only I believe) having constant power...if it's unplugged from the JB...then I lose the constant power....Any idea what the path is for that wire from the JB to the Air Bag Control Module?? Is there any kind of junction or module inline with that wire?? I don't want to hack wires if at all possible...Awaiting reply..LOL

That Green/Yellow tracer wire goes direct from fuse 26 in the JB to the Airbag Control Module. Key in RUN position powers the fuse (through the ignition switch).

The Dark Blue/Yellow tracer wire goes direct from fuse 27 in the JB to the Airbag Control Module. Start-Run bus. Engine start/engine running.
 
I read that you installed a replacement JB, but you may be interested in knowing that circuits for the Airbag, HVAC, and Horn all go through JB connector C4. You may want to inspect the body harness end of the connector closely for corrosion, etc., that may cause shorts in these circuits.

JBconnectorC4-1.jpg
 
In the picture of the JB....the plug in the upper left corner is where the light green with yellow stripe originates from and feeds into the main harness going out into engine compartment....and if it doesn't junction anywhere else....then I assume it comes back into vehicle and goes all the way down trans tunnel to airbag control module....there isn't a junction near steering column before it goes down trans tunnel? I will double check that large bolt in connector at JB an spray with contact cleaner as well...Will post my results later
 
The Power Outlet is powered directly off the battery. It goes through connectore c4 as well. The fuse for the power outlet is F1 in the JB, 25A. See pic.

The Power outlet wire from C4 to the outlet is a 16 gauge wire, Red/Light Blue tracer.

It may be the bad boy you're looking for. Pull fuse F1 and see what happens (C4 connected).

F125APowerOutlet.jpg
 
Unplugged the bolted in block...no corrosion that I can see...sprayed out and connected....unbolted connector under dash to the right of steering column (The BIG connector that is bolted together) No Corrosion...sprayed it out as well and reconnected....as near as I can tell...that harness goes from JB to Block under dash by Column and T's down transmission tunnel to the Air Bag Control Module....As I was getting ready to put JB Plug back in...I thought I should pull the back plastic cover off of it and look for wires that may have gotten hot or rubbed...found a pretty good bit of corrosion...only on that back side...doesn't show through on plug side...I sprayed it down and picked away as much as I could and plugged it back in...the same issues with the horn and if I put Fuse 26 Back in the blower goes back to working without the key...but I may be on the right track...I may grab that harness from the Junkyard or DR. MOAB and swap it to see if that takes care of the problem...we'll see where that gets me....
 
Unplugged the bolted in block...no corrosion that I can see...sprayed out and connected....unbolted connector under dash to the right of steering column (The BIG connector that is bolted together) No Corrosion...sprayed it out as well and reconnected....as near as I can tell...that harness goes from JB to Block under dash by Column and T's down transmission tunnel to the Air Bag Control Module....As I was getting ready to put JB Plug back in...I thought I should pull the back plastic cover off of it and look for wires that may have gotten hot or rubbed...found a pretty good bit of corrosion...only on that back side...doesn't show through on plug side...I sprayed it down and picked away as much as I could and plugged it back in...the same issues with the horn and if I put Fuse 26 Back in the blower goes back to working without the key...but I may be on the right track...I may grab that harness from the Junkyard or DR. MOAB and swap it to see if that takes care of the problem...we'll see where that gets me....

That corrosion may go deeper than what you can see.

Did you try removing fuse F1 in the JB to see what happens? (previous post)
 
That corrosion may go deeper than what you can see.

This is VERY possible....I was going nuts thinking about the Jeep last night...so got up a bit early for work and stopped at the Junkyard on the way in (They only have 1 98 XJ...and it's getting picked over pretty good!!)...popped in...paid my dollar...and went to town grabbing that harness...got to work only about 5 minutes late...lol....then antsy all day waiting to be able to pull the Jeep in to see what happens....So I get it pulled in...undo the 2 bolt in connectors and all the plug in connectors...I drapped the replacement/test harness over everything (Not putting that sucker in unless it's going to fix my problem...lol) hook everything up and ran a jumper from ground to the ground that terminates at the Air Bag Control Module....Cross my fingers...and put a Fuse in 26....double check to make sure Fan was on so if it still isn't gonna work that the fan will come on as soon as it's installed....fan doesn't come on...i double check again....we seem good....put the horn relay back in it's socket...fully expecting the horn to start blaring...it doesn't...seated it fully....grabbed the air bag/horn pad...installed it...and the horn works as it's supposed to....So the problem is in that harness that goes from C209, C4...several small white plugs near JB...and the Big Junction under dash near column and the Air Bag Control Module....tomorrow i will probably install it correctly...and at some point I want to dissect the old harness to see where it was bleeding power from (My thinking at this point is corrosion...but we shall see!!!) Thanks For all Your Help Sidewinder and DR. MOAB!!! And everyone else that posted suggestions!!!
 
This is VERY possible....I was going nuts thinking about the Jeep last night...so got up a bit early for work and stopped at the Junkyard on the way in (They only have 1 98 XJ...and it's getting picked over pretty good!!)...popped in...paid my dollar...and went to town grabbing that harness...got to work only about 5 minutes late...lol....then antsy all day waiting to be able to pull the Jeep in to see what happens....So I get it pulled in...undo the 2 bolt in connectors and all the plug in connectors...I drapped the replacement/test harness over everything (Not putting that sucker in unless it's going to fix my problem...lol) hook everything up and ran a jumper from ground to the ground that terminates at the Air Bag Control Module....Cross my fingers...and put a Fuse in 26....double check to make sure Fan was on so if it still isn't gonna work that the fan will come on as soon as it's installed....fan doesn't come on...i double check again....we seem good....put the horn relay back in it's socket...fully expecting the horn to start blaring...it doesn't...seated it fully....grabbed the air bag/horn pad...installed it...and the horn works as it's supposed to....So the problem is in that harness that goes from C209, C4...several small white plugs near JB...and the Big Junction under dash near column and the Air Bag Control Module....tomorrow i will probably install it correctly...and at some point I want to dissect the old harness to see where it was bleeding power from (My thinking at this point is corrosion...but we shall see!!!) Thanks For all Your Help Sidewinder and DR. MOAB!!! And everyone else that posted suggestions!!!

Good work getting it fixed.

Let us know what you find when you dissect the old harness.
 
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