heater question

[littlebigman]

My heater fan is not moving, indicating that the motor is not working, what is my next step in attacking this? Also how do you clean out the heater box of debris and junk that is clogging up the heater? Step by step tips would be most appreciated.

c

[illegalFSJ]

Use a jumper wire to get battery voltage straight to the blower motor itself. If it still dosen't work, replace the blower motor.
Good luck!

[Obi-Wan]

I referbed my heater box last winter. I'm afraid I didn't take any photos, but the writeup I did is at:

http://www.jedi.com/obiwan/jeep/wagoneer/heater.html

After you've gone to all the trouble of dismantling the heater box, you'll not want to do it again. I strongly recommend putting a screen under the cowl vent. I wish I'd given mine a fresh coat of paint while I had it out, but I didn't. :-( Kinda hard to paint while it's installed.

[427CometGuy]

I agree with Obi, cleaning the box is a pita. I wound up removing the blower motor/assembly and using a shop vac to suck out the crap from the heater core housing, which saved me from removing the whole dang thing.
The downside of this is you cannot inspect the innards of the core housing and must rely on feel for clues.

Dave

[andy d]

try this. turn on the heater to high. then go to the htr mtr and give it a good tap with a screwdrvr handle. in most cases that will start it. in fact, ive never had a smoked htrmtr on a fsj. it has a stuck brush. you can either keep a screwdrvr handy, or you can replace or fix the motor. fixing the motor is pretty simple.i havent done it in ten yrs or so, these directions may have missed a few of the finer points. rmove it, 4 5/16 screws,and unplug it. it takes a little fiddling to get it out of the housing. then get some light oil. 3in 1 or something like it. do this inside on a sheet of newspaper. let the motor get warm. this is to make the plastic tabs on the squirrel cage get flexible. gentley pry the tabs away from the shaft. if one snaps ,dont worry, a mini hose clamp works fine to re-clamp it to the shaft. wiggle the fan off the shaft. sanding the crud off the shaft before hand helps this process. scratch a couple of reference lines on the case before you take it apart.unscrew the bolts holding the case together. on the newspaper, open the case. chances are all sortsa crud will fall out. pine needles were what came outta the motor from my 81. clean that crud out. undo the brushes.be carefull, they are spring loaded. fiddle with them to make sure they travel freely in their holders. put them back in their holders with the springs. next use a pencil eraser or a brass bristle brush to clean the commutator on the shaft. thats the round copper plates the brushes sit on on when the motor is together. dont use sand paper on them. it roughs them up and causes the brushes to arc. oil the bushings on the ends of the motor. clean the shaft where the bushings ride.oil the bushings.the bushes need to be held back from the commutator. use some wire hooked around the leads and pull them gently back. slide the armature into the case. put the bolts back in. hook the motor up to 12volts, ground the case and hang on. it should torque right up. push the fan back on. , vac out the htr box before putting the motor back in. i had this trouble with every wag i ve had. i fixed it in everyone except my 88s. i have a couple of re-habbed motors. i prolly should have fixed it on my old 88, but i got lazy and just used the screwdrvr. prolly about new yrs the one in my new 88 will start acting up. of course it wont happen to me, but to Marina. :D btw ,ive heard the motor is about a 30$ item at an auto parts store. i think it also fits about every ford from 56- to 86.

[qmichael]

I would try to run pos+ v to the motar once you have removed it,remember you need to ground the case to the any part on the frame or to the neg -12volts on the batt. .If the motar works check for pos voltage going to the line that feeds the motar .You can check with a volt meter or a 12 v light bulb like a brake light ,if you are not getting any voltage to the feed line then you need to check line and fuses.Don't forget to clean out the heater box mine was filled with leaves and such, I think will remove the grill in front of the windshield and cut a pice of screen to size to keep this from happing.

[fitron74]

littlebigman,
Check the thermistor.It's the under the male plug that the wiring harness plugs into on the box with the blower motor.Testing procedure is in the Haynes manual for FSJs.
Fitron74

[letank]

sometimes the squirrel cage will move toward the heater box or the motor itself... rubbing on it..... and you have a non running fan

Also i tried >>>>use some wire hooked around the leads and pull them gently back.<<<<

but there is no window... so this did not work for me. A new motor without squirrel cage is about $25 at the zone..... but make sure the other parts... are working. If the resistor fail, you only have the high speed

Cheers

Michel

[The Anti-Chrysler]

Has anyone tried pulling the heater box assembly without taking the inner fender well out?? I put a motor in my '84 (was missing), and I see by the lovely smells that there's a mice nest, or remnants of, jammed inside there. I'd rather take the whole unit off to clean it, but don't know if it'll come out without taking off the fender inner panel for access.

[billybooster]

Mice iz nice

[Marvin Gates]

There are 4 7/16 nuts that hold the whole thing on, two on the outside just behind the exhaust manifold on the firewall and two on the firewall inside (if you don't have a/c its a snap) if you have a/c losen the screws that hold the a/c to the dash (underneath) 3 or 4 metal screws, drop the a/c down out of the way. Pull the whole heater box out and take the box apart (whole bunch of 1/4 in screws) in the box, then you can clean it properly and check your heater core to see if it is leaking. Looks like a PITA but actually pretty simple. When you get done, its one of them things you will say to yourself "that wasn't bad". :D :D :D smile.gif

[ October 31, 2003, 08:55 PM: Message edited by: Marvin Gates ]

[littlebigman]

To everyone who helped:

Thank you.
I am going to give it a shot tommorrow and see if I can figure it out. Hopefully it won't be a PITA.

Thanks again.
Casey