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F#@*ing transmission is killing me!

J

jrowell

NAXJA Forum User
Location
Bakersfield
in my effort to get my TC to start locking up (http://www.naxja.org/forum/showthread.php?t=926569&highlight=tq+tech), I started having issues (or at least noticed the issues) with my "trans" fuse blowing. As soon as I put it in drive... pop! Anyone know what would cause this fuse to pop? I tried putting in a bigger fuse (I know, bad idea... but at least I have not wire jumpered it yet!), and it blew the fuse by the TCU under the dash... as well as the trans fuse. Any help would surely cause me to quit pulling out my hair!

87xj 4.0 aw4 np231
 
Take the knee-board down under the dash....you should see the TCU on the pass. side. Unplug that connector, wiggle it around a bit. See if that helps out. If nothing else, you can unplug that connector and drive it as a manual =P
 
RaccoonJoe said:
Take the knee-board down under the dash....you should see the TCU on the pass. side. Unplug that connector, wiggle it around a bit. See if that helps out. If nothing else, you can unplug that connector and drive it as a manual =P
Click to expand...
Ya, I've had that out. Tried a different TCU also. No dice. And the Torque Converter won't lock with it unplugged... which I think is the root of my overheating problem.
 
mine is running quite warm as well... I can't tell when its locked up or not... I never got a diagram on the manual trans mod. Anyone got it?
 
have you checked for shorts elsewhere? traced the wiring back to the dash? I know it may sound stupid to even ask, but sometimes its the simple fixes that end up costing us the most!
 
Bored400 said:
have you checked for shorts elsewhere? traced the wiring back to the dash? I know it may sound stupid to even ask, but sometimes its the simple fixes that end up costing us the most!
Click to expand...
What! There are a thousand wires in there, you expect me to trace it! Just kidding... I have followed it as far as I can reach. I have not tore my dash apart, but followed it the best I can. Looks o.k.
 
Bored400 said:
Here's a thought...is the tranny in a bind? Is the TC? Hmmmm...
Click to expand...
It drives fine. If it weren't for the freeway overheating I would not have noticed the TC not locking up. I did notice the power/comfort switch on the dash stopped working. No clunking, strange noises, loss of power.
Could the tc be bound without any other symptoms?
 
Well, I'm just thinking that if the tranny or tc are binding or air locking or whatever that it's gonna make your engine work harder ( hence the overheating ) and quite possibly blow a fuse. Once you short that circuit, then all kinds of stuff could happen. I just read your TC tech post and read about your brake pedal deal...this shit seems to be in a downward spiral! Has this really been going on for like 2 years? *Edit* I'm a dumbass...I was looking at your join date, not the post date...never mind!
 
Last edited:
Bored400 said:
Well, I'm just thinking that if the tranny or tc are binding or air locking or whatever that it's gonna make your engine work harder ( hence the overheating ) and quite possibly blow a fuse. Once you short that circuit, then all kinds of stuff could happen. I just read your TC tech post and read about your brake pedal deal...this shit seems to be in a downward spiral! Has this really been going on for like 2 years?
Click to expand...
Well, it's been going on since before I bought the jeep SEVEN YEARS AGO. I picked it up for $700 because it had a cracked head (due to overheating) They couldn't figure out why it was overheating, so they sold it. I got it and replaced EVERYTHING that I thought could be causing it (while turning it into a trail vehicle). Got a new head and it was good to go... but still ran hot on freeway. It's just a trail vehicle, so it lasted awhile till the engine blew (had almost 300,000 miles) Dropped in an engine out of a 94 (that did not have overheating issues) and had the Transmission rebuilt.
No dice, damn thing ran the exact same temp!
 
If the fuse is popping it is fairly obvious something is shorting out or has a very low (too low) resistance.
This guy does a pretty good job of laying out a troubleshooting scheme. For use with an ohm meter.
http://www.transonline.com/transDigest/magazines/1997-10/Shift Pointers/index.html
Though some of his tests where likely thought up in the office and probably never tried on the vehicle. There are a couple of minor mistakes in his procedures.
Solenoid resistance would probably be a good place to start.
 
Last edited:
8Mud said:
If the fuse is popping it is fairly obvious something is shorting out or has a very low (too low) resistance.
This guy does a pretty good job of laying out a troubleshooting scheme. For use with an ohm meter.
http://www.transonline.com/transDigest/magazines/1997-10/Shift Pointers/index.html
Though some of his tests where likely thought up in the office and probably never tried on the vehicle. There are a couple of minor mistakes in his procedures.
Solenoid resistance would probably be a good place to start.
Click to expand...

That's a good link with some good info. Thanks.
 
I agree on the solenoids. They are in the transmission. So try disconecting thje wiring harness at the transmision. If the fuse stops blowing it is a bad solenoid in the tranny or maybe a shorted NSS switch. If the fuse blows again, then check the wiring harness to the tranny for burned insulation (exhaust contact damage!) shorting the wires. If not one of those and it still blows the fuse work back to the tranny computer and see if it is shorted internally.

I would bet its a burned or damaged wire near the tranny NSS/Solenoids connectors.


8Mud said:
If the fuse is popping it is fairly obvious something is shorting out or has a very low (too low) resistance.
This guy does a pretty good job of laying out a troubleshooting scheme. For use with an ohm meter.
http://www.transonline.com/transDigest/magazines/1997-10/Shift%20Pointers/index.html
Though some of his tests where likely thought up in the office and probably never tried on the vehicle. There are a couple of minor mistakes in his procedures.
Solenoid resistance would probably be a good place to start.
Click to expand...
 
Ecomike said:
I agree on the solenoids. They are in the transmission. So try disconecting thje wiring harness at the transmision. If the fuse stops blowing it is a bad solenoid in the tranny or maybe a shorted NSS switch. If the fuse blows again, then check the wiring harness to the tranny for burned insulation (exhaust contact damage!) shorting the wires. If not one of those and it still blows the fuse work back to the tranny computer and see if it is shorted internally.

I would bet its a burned or damaged wire near the tranny NSS/Solenoids connectors.
Click to expand...
I will check that out, that is very helpfull info. Thanks. I know when I got it the CPS wire was burnt, so I keep checking that area to make sure no wires are in danger... but I will have to take a closer look.
 
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