Fuse blows only in Overdrive.
 

Hello. I was wondering if anyone else has heard of this problem. Fuse #11 (20 amp mini) in the fuse box inside the kick panel keeps blowing. The manual lists this fuse as the Ignition/run/start. It is a 1997 Jeep Cherokee Country with the 4.0L and 4 speed automatic. I was driving on the freeway about 65 and it just shut off. Found that I could put it in every other gear and it didn't blow.

When the fuse blows the engine shuts off but will still crank over. I took apart the neutral safety switch and it looked good. I found the service manual for the aisin-warner aw-4 and it says to unplug the TCU and drive the jeep manualy shifting for it. (this is suppose to tell you if the TCU is bad or not) I did that and still it blew the fuse as soon as I slid it into overdrive. Now the jeep is reving up to about 2500 and staying there for a while then going down to 1500-1800. I replaced the TPS and still the same thing. No other blown fuses other than #11...

A few weeks before I was having problems with is starting and immediatly shutting off or starting and running really rough. It was random and always went away as soon as I restarted it. I'm leaning toward a short or possibly a bad PCM.

Any input would be greatly appreciated. Also does anyone have a wiring diagram for a 1997 cherokee (not grand cher.) I have a haynes but its very limited.

Thank you.:wacko: