98 Cherokee Sport...BLOWER ISSUES

New to the Forum...I picked up a 98 XJ for my Step Daughter that I'm fixing for her 16th Birthday....It has a slight lift on it and looks pretty decent....What my problem is....is the blower....With NO KEY in the ignition...the blower will still run...and it runs the battery down if the battery is left connected...I want to fix this RIGHT...so I don't want to do any bypassing or what not....I can unplug the ignition switch...blower still runs...no hacked wiring that I can see anywhere in this rig...has anyone run into this problem?? Feel free to ask me questions and I can tell you everything I've tried and such...I may have forgotten a couple things...so shoot with the questions unless you happen to know what it is...LOL...Thanks Guys!!!

relay for the blower can be stuck? maybe the switch itself is broken? the 98 has a bit more nifty things on it than the older ones. im used to 96 and older. look up the relay location for the fan blower and pull it out and see if it shuts off.

Replaced the Blower Motor Relay...no change...Unplugged the blower motor resistor...no change other than high only...but still doesn't shut off....swapped out control head...no change....the control has an off for the whole ac/ heater setup...that seems to shut down the blower....but if it gets left in any other position...blower stays on.....no key needed

I can't remember the wiring schematic entirely but have you tried pulling the blower motor fuse? It should be in the fuse box as a 40amp fuse under the hood if I remember correctly.

Note from DJ
Have a look at this problem
97 XJ Fuel pump issues
http://www.naxja.org/forum/showthread.php?t=1096349
See post #10 by Sidewinder CC
For HVAC Blower fuse location in the Power distribution box under the hood & the HVAC Blower Relay Fuse location in the right hand or passenger side kick panel.

Do you have a wiring schematic for the 98XJ yet?

Unplug the ignition switch and see if it stops, you may just have a bad ignition switch

fordtrucknut said:

Replaced the Blower Motor Relay...no change...Unplugged the blower motor resistor...no change other than high only...but still doesn't shut off....swapped out control head...no change....the control has an off for the whole ac/ heater setup...that seems to shut down the blower....but if it gets left in any other position...blower stays on.....no key needed

Click to expand...

Here's a schematic of the HVAC control that I prepared for my use. it's applicable to the '98-'01 XJ.

As you can see, the blower is powered from fuse F6 (40 amp) in the PDC any time the ignition switch is in the RUN position. This is achieved through the blower motor relay. So, any time the ignition switch is in RUN the blower is hot. The HVAC control mode select switch provides a ground to the blower motor when the mode switch is in any position but OFF (O), as you've seen. Since the blower motor is provided with battery voltage any time the ignition switch is in RUN, the blower motor control is provided by giving it a ground circuit, direct in fan speed switch #4 position and variable in positions 2, 3, or 4 through the resistor block.

It surprizes me to read that when you detached the electrical connector from the ignition switch that the blower still runs (is this correct?).

Note that power to the blower motor relay control coil comes from fuse F25 in the junction block and that it is powered from the RUN A22 bus, which goes through fuse F3 (40 amp) in the PDC. A22 is powered through the ignition switch when it is placed in RUN. A22 (F25 JB) also powers the transmission shift lock solenoid, so if you can shift your transmission with the ignition switch OFF/LOCK it may indicate that the A22 contacts in the ignition switch are welded closed.

Try removing the blower motor relay and see if the blower still operates. If it does power is somehow bleeding into the circuit between pin cavity 87 of the blower motor relay connector and pin A of the blower motor. If it doesn't run, do this:

Remove fuse F25 from the JB and check for voltage at pin cavity 86. If you see voltage there's a short to power in that circuit. If you see zero volts, the power leak to F25 is upstream of the fuse.

Pull fuse F3 (40 amp) in the PDC - Second fuse up from the bottom in the laft bank of maxi fuses - and check for voltage at pin cavity 86 again. If you see zero volts I would suspect the ignition switch. If you still see voltage at pin cavity 86 with F3 removed there's a short to battery voltage in the circuit between F3 and F25 in the JB.

Any short to power could/may be in connector C209. As you can see the HVAC control circuits go through C209.

Check these things and get back.

Schematic:

Sidewinder CC said:

It surprizes me to read that when you detached the electrical connector from the ignition switch that the blower still runs (is this correct?).



Try removing the blower motor relay and see if the blower still operates.

Click to expand...

Correct...Blower still operates with ignition switch harness unplugged....It DOES NOT operate with blower motor relay out tho....I thank you for a bunch of areas for me to probe and check too!!! I will be sure to get back to you with any results....does anyone have a COMPLETE wiring diagram for the 98 XJ??? I'm trying to find one that I can dig through as well.....I'm a big Ford guy as you can probably tell from the screen name....and I have wiring diagrams for my old trucks that cover from the front to the back of the vehicle...with EVERYTHING displayed. That's what I'd like to find for the 98 XJ

fordtrucknut said:

Correct...Blower still operates with ignition switch harness unplugged....It DOES NOT operate with blower motor relay out tho....I thank you for a bunch of areas for me to probe and check too!!! I will be sure to get back to you with any results....does anyone have a COMPLETE wiring diagram for the 98 XJ??? I'm trying to find one that I can dig through as well.....I'm a big Ford guy as you can probably tell from the screen name....and I have wiring diagrams for my old trucks that cover from the front to the back of the vehicle...with EVERYTHING displayed. That's what I'd like to find for the 98 XJ

Click to expand...

Did you try shifting gears (brake pedal depressed) with the ignition key OFF? Fuse #25 also powers the Shift Lock Solenoid with the Ignition Switch to RUN. If the Shift Lock Solenoid is activated with the key OFF power is getting to fuse #25 somehow.

You may want to do this test to see if fuse #25 in the JB is being powered with the ignition switch OFF:

Refer to my schematic.

Remove the Blower Motor Relay (again). Ignition switch OFF, probe relay connector pin cavity 86 and see if you are getting battery voltage. Note that the bottom of the relay should have each pin numbered so you can establish the pin cavity relationship in the connector.

If you don't see battery voltage, power is leaking into the Dark Blue/White tracer wire that goes from the fuse to the relay connector. Note that this wire goes through pin 9 of connector C209 and that power from fuse #6 in the PDC goes through pin 8 of C209 (possible source of the short). If you do see battery voltage when testing pin cavity 86, pull fuse #6 in the PDC and see if it goes away.

You can see the Dark Blue/White tracer wire in the pic below.

I tried last night leaving the battery connected...but with the mode switch off...so the blower was off....I have a draw somewhere...battery was dead when I went to pull it in tonight to start digging....

Ok Sidewinder...here is what I've got for ya.

Pulled Blower relay...have voltage at pin 86

Pulled F3 at PDC...still voltage at 25 at JB

Voltage present at pin 86 with F3 Removed

Unplugged Ignition....still have power at F3 and F25

Unplugged C209 (I assume that is the plug into the mode switch/fan switch)...Still power at F3 and F25

Removed F25 at JB...No power at Pin 86 of Blower Relay

Removed F6...Still have power at Pin 86 of Blower Relay

With F3 out....so no power getting out....that tells me it's getting a power feed somehow from somewhere...have you seen JB's go bad???

I also tried the shifting out of park...that hasn't been an issue....that seems just fine

I await your ideas on this...Thanks a TON!!!!

fordtrucknut said:

Ok Sidewinder...here is what I've got for ya.

Pulled Blower relay...have voltage at pin 86

Pulled F3 at PDC...still voltage at 25 at JB

Voltage present at pin 86 with F3 Removed

Unplugged Ignition....still have power at F3 and F25

Unplugged C209 (I assume that is the plug into the mode switch/fan switch)...Still power at F3 and F25

Removed F25 at JB...No power at Pin 86 of Blower Relay

Removed F6...Still have power at Pin 86 of Blower Relay

With F3 out....so no power getting out....that tells me it's getting a power feed somehow from somewhere...have you seen JB's go bad???

I also tried the shifting out of park...that hasn't been an issue....that seems just fine

I await your ideas on this...Thanks a TON!!!!

Click to expand...

It would take awhile to digest all the data you've presented, but I'll do that today.

C209 is that large green connector behind the glove box. See pic and schematic.

have you seen JB's go bad??? Speaking of JB's, take a look at these photos of a corroded JB. This is the second set of photos I've seen of ate up JB's but have read of others being corroded.

Photos were posted on the CF Forum by Steven72192. He said he had lots of electrical problems so he went to the JB. Obvious fix.

I think this is strictly a junk yard part. I can't find it in my parts catalog anywhere.

If you do need a replacement JB I think I would be looking for a 1998 or 1999 JB. I'm not sure if the JB pin outs for a 2000 or 2001 JB are the same as '98/'99. '97 would be iffy at best.

Talk about stage 4 cancer!

Got a chance to grab a perfect used JB from the self pull yard (98 and newer don't seem to make it there very often)...Popped it out...and pulled back cover to make sure...spotless...zero corrosion....so I figured for 17.99...I'd give it a shot....pulled the original JB out...popped the back cover...small bit of corrosion just on one side....thought maybe it was gonna have it fixed....NOPE..blower still works without the key on!!! Starting to get really annoyed!!!....I see ZERO wire hacks of any sort!!! :flamemad:

Ok...Been digging some more....unplugged C209....have power at 2 pins that have blue with white trace wires....Jump on my ALLDATA (I'd still like to find a full wiring diagram for this pig....But....LOL)...was able to find the diagram in sections (PITA!!!)....

Fuse 25 (Which is the keyed blower fuse...I Believe)....is tied to Fuse 26(Which has something to do with Air Bag Control Module)....AND if I plug the relay in to the NEW JB I just replaced the old one with...the horn stays blowing constantly.....with the old JB...the relay would just click...which I knew could be a problem....but wasn't sure how much of a problem....TILL NOW!!! I'm wondering (Because I don't have much experience with air bag systems)...if I have a bad air bag or something in that area or an airbag control module issue....but PROGRESS at least!!! Thoughts???:wave:

Left battery hooked up overnight (It goes dead if I don't disconnect it!!!)....went out and opened it up...stuck key in ignition and it FIRED RIGHT UP!!!! No dead battery!!! I'm on the right track!!! Still want as much input as you can give tho!!!

When you get a chance, take a look at the back of your AC/Heater Control panel and see if there is a small electrical connector on the back of the temp selector (blue to red range) or is the a cable attached to this selector.

'98 is supposed to have a cable controlled blend door actuator but I'm curious if they started to install electric controlled blend door actuators near the end of the '98 production run.

The '99 electric blend door actuator has two blue/white tracer wires going through C209.

Here's a schematic I made for my own use on my '99 Blend Door Actuator circuit, so you can see what I'm referring to. C2 connector would be that small connector I asked about.

I'll look tomorrow when I'm at the shop...but pretty sure it's cable...it has a white toothed piece on the back of it at the control head....

In your opinion...if the horn continues to blow if the horn relay is installed ....the airbag/horn pad just doesn't feel right to me....and the draw is because of airbag...would you think that is was the airbag/horn pad....or the clock spring that is causing the problem?? DRMOAB has a airbag/horn pad he can sell me...and I'm gonna grab it ci=uz it just doesn't feel right...and he has a line on clock springs at a fair price if I need one...Thoughts??

BTW, I talked to my guy. He has a clock spring if you need it.

Sounds good....I think we'll see what that horn pad/air bag does...and go from there...unless I happen to stumble onto something else in the meantime:read:

fordtrucknut said:

I'll look tomorrow when I'm at the shop...but pretty sure it's cable...it has a white toothed piece on the back of it at the control head....

In your opinion...if the horn continues to blow if the horn relay is installed ....the airbag/horn pad just doesn't feel right to me....and the draw is because of airbag...would you think that is was the airbag/horn pad....or the clock spring that is causing the problem?? DRMOAB has a airbag/horn pad he can sell me...and I'm gonna grab it ci=uz it just doesn't feel right...and he has a line on clock springs at a fair price if I need one...Thoughts??

Click to expand...

You could try a different airbag module before replacing the clockspring and see if it helps. Although the clockspring is notorious for going bad, to save the initial effort of tearing everything apart (steering wheel removal) to change the clockspring, the airbag change first may be the way to go. If the horn continues to blow, then consider a new clockspring. It's extra effort to remove the airbag module again to replace the clockspring but it may save you the extra expense of a new clockspring.

Make sure the battery is/has been disconnected before attempting to change the airbag module, and make sure the airbag module is installed securely before testing it. As a safety precaution, have no one in the vehicle when hooking the battery bck up after the airbag has been installed in case it decides to deply.