blowing fuses.

I have a 95 jeep cherokee classic. It runs strong for several miles then stalls at low rpms. It had done this only on occassions however, now it keeps stalling and blowing the fuse leading to the pcm under the hood. When the fuse is blown, there is no spark but all accessories continue to work. When I replace the 30 amp (big) fuse, it runs strong agian. I have checked for shorts and cant find any. if the pcm is going out will it blow fuses or simply go out ? Any help would be appreciated.

if there is an internal short in the pcm then yes. did you check the back side of the fuse box its self? i guess my only reservation would be, that the car runs fine until the fuse blows. i would think that if there where that big of a short in the pcm(ecu) that the engine would not run at all or would run/do strange things. ? you can take the pcm out and look at the pins to look for signs of excessive heat. open it up and look at the board for signs of that and water damage

i agree ecm ready to fry and i'd check like he sais or maybe maf sensor. because they'll run then warmed up it'll up and die. if it dies or if it has does it start right back up after you replace fuse?

I thought I found the problem , Four wires coming from the O2 sensor were bare/ melted to the header. I fixed them with new wires and it ran strong for several miles until the same problem occured. Im going to recheck all wires this am . Could the short have fried the O2 sensor or worse. If so why would it run strong then blow a fuse? ....:screwy: .

i would find a wiring diagram for your car and trace back the wires all the way back to the fuse,then to the pcm. just to make sure it did not fry at multiple spots.then you will need to pin(ohm) it out to insure that the circuit is ok. I would be concerned mostly about the heater circuit and what it has done to the feedback circuit.
after repairs, get ahold of a scan tool and check the o2 pid. see if it is swiching ok (from 0-1volt)and that it does not read over 1 volt.
at this point i would also replace the o2 sensor while your at it. just incase there is an internal short.