Ok..this is going to be a pretty lengthy post the reason being trying to vet "solutions" I have already tried thank you for bearing with me. About 2-3 years ago my Jeep started backfiring very lightly and very seldom while driving on the highway at 60-75 mph. Sprayed the intake and it got worse. Ran "key codes" came back bad IAC..replaced. No difference. Bad TPS symptoms replaced that..no difference. Kept getting random codes and started searching forums for similar symptoms. Kept getting worse. Ended up cleaning grounds..replacing TPS..IAC..MAP..CPS..CAMSHAFT P S..TSS..CTS.. to no avail. (An example is I replaced the TSS because the symptoms of a bad one.. speedometer needle would bounce up and down and trip odometer would roll EVEN THOUGH IT WAS PARKED IDLING)...Checked cats..O2 sensors..etc. Got a cheap OBDII code reader..Bought a multimeter. (don't really know how to use it fully) It sometimes will not start unless the gas is pressed all the way to the floor..sometimes it will start normally no gas at all just turn the key. Sometimes it will not idle after I start it ..sometimes it will..rev the rpms and hold for a minute..it dies when I let off the gas. Do the same thing and ease out of it and sometimes it will idle. Some times it will not idle when put in gear or it idles really rough like a "lope" when you have a race cam. After you get it started and either drive it or rev and hold it for awhile it will not start again for about 10-20 minutes. (symptoms of a bad CTS) Sometimes after revving it at 3000-4000 rpm for a minute it will backfire like a freakin 12 guage when you turn it off..sometimes not..When I do drive it I drive with both feet (brake\gas) to keep it from dying and throw it in neutral at lights..When parked and holding at 3000-4000 rpm sometimes it "sputters and hiccups" sometimes it "drones" (audible definition of the word) going up and down at different "pitches" ..sometimes it doesn't.. ..NOW on top of that..about one and a half years ago..the horn..power seat..vanity lights..go out. At the same time the door locks quit but I can hear and feel the relay engaging in the relay module under the dash. At the same time these things started acting up the power windows now will go up and down WITHOUT THE KEY BEING ON. Before (to use them) the key had to be ON. The after market radio face light flickers\fluctuates when turned up loud then the radio cuts off..comes back on for a min then cuts off again. Will stay on and not fluctuate if turned to low volume. The OBDII will not connect now but did before. (It is like it is slowly dying.) I have looked at the ECU checked connections etc.. As far as I know the ECU has NOTHING to do with the cabin issues. I have pulled the PDC under hood and checked wires connections and for corrosion. Same with fuse block on firewall drivers side under dash. Checked fuses and relays. There is a short somewhere I believe I just don't know where. I believe one time awhile back when it was dark I saw a faint blue spark putting the little bar that holds the hood up back in the clip on the passenger fender. The issues to the cabin seem tied to the relay module under the dash since everything acting wonky has a relay in that module. If anyone has an idea or knows of how to find "the ghost" I would be grateful. On a side note I changed the keyed ignition switch and fan speed switch and both had melted insulation at the switch. I heard that is common on this year cherokee and all the ones at the yard had melted fan speed switch connections also. I tried tracing the wires looking for bare or melted spots. Could the ignition tumbler be defective and causing these in cabin issues ???. Js.. Thank you for your time and attention in this matter 😊 P.s. it reads code 44 now doing "key trick"..have no clue what FJ2 circuit is 🤷..not an electrician just have basic knowledge of..js

 

Your post, although long and detailed is difficult to read, as it has no punctuation or paragraphs.

Unfortunately you will get limited responses. It needs to be edited. I am trying to be helpful for you here I promise

I tried to read through it, and it strikes me you may have a problem with your ignition switch, which is not uncommon

You may have more than one fault, poor earths being another major & common suspect

good luck, us 96ers got to stick together!

 

Thank you for the reply awg. When I replaced the ignition\tumbler keyed switch I had to get one for a 96 viper from the parts store. The one they kept giving me for a 96 Jeep Cherokee was not the right one. That has happened ALOT with this jeep.(wrong parts for 96 )Would a bad ignition\tumbler keyed switch cause the weird electrical issues ??? Also do you know what and where a FJ2 circuit is ?? code 44. I am assuming "Fused (something J) 2.. wth is it ??? Lol. Thank you again for responding any help is greatly appreciated😊

 

things that should only operate with ignition switch on is a mentioned issue you have

I suggest you get an OBD2 reader

I bought this one for $30, as it works on a '96 (many wont)

BAFX OBD2 Review – 2022 Buyer’s Guide (obd2scanners.org)

You also need to free download the manual if you havent already from this site

'97 for the engine, '95 for most other parts

 

The Windows operate now wether the key is on or off. Originally they would only operate with the key on...the electric seat..horn..vanity mirror lights..door locks do not have to have the key on to operate correct ??? The door lock relay under the dash clicks and I can feel it engaging but the locks won't work. I switched the relays with a known good one..no difference. I have an OBDII scanner that worked..now it doesn't want to link to the vehicle. I know it is something simple..just finding it. Been jacking with this booger for over 2 years now. It ran awesome for about a year then bang..the engine issue. Another year or so then bang..the in-cabin electrical issue. It's been 3 years now since I have had this jeep. Any help is greatly appreciated. P.s. the Manuel for the Jeep ??? Is that the same site as the scanner ??? I only see one site.

 

Technical Manuals | cruiser54

I have the electrical chapter of '96

maybe this link will work

96 FSM ELECTRICAL - Google Drive

 

My 93 is most certainly different, but my cross body harness was smashed in the drivers footwell area.

This caused mine to have many weird electrical issues.

I had back feeds and things working when they shouldn’t.

Hope theirs helps

Jeff

 

Ok. Thank you. What is the "cross body" harness ??? Also there is a related thread from Davek on 3\10\2014 titled "ANOTHER NO START 96 CHEROKEE". It talks about something called CCD....CCD BUS...BUS PINS @ dlc...I don't know these terms can someone explain please and tell me where they are located ??? I guess the link awg sent doesn't work. It said my account did not have access. I requested it to be sent. Does anyone have a picture of the PCM connectors with the pins numbered ?? I bought a multimeter but really don't know how to use it other than checking voltage. Do not know much electrical. Any help is appreciated. This jeep is my only transportation and I am kinda living out of it also. I really need it to run like it did when I got it. Thank you in advance for all your help guys.

 

On my 93, which will be some different, there is a harness that connects the left and right side of the jeep electrically.
On mine it connects down at the drivers footwell under the kick panel. It ran from there tho the passenger kick panel.
My power windows, locks dome lights and other things all acted up.

You need buy a factory shop manual set for your 96.
The electrical schematics and harness layout drawings are unmatched.
The manuals are expensive but will pay for themselves.

Jeff

 

I believe the link to the '96 electrical Chapter does not work, I set it up with instructions from someone else. I do not know why it does not work, but will try to see if I can figure out how, Gmail notifies me people want permission to look at it, but I dont know how...however, the guy that told me how to set it up for me uploaded it to his Google Drive account, and that does work. I will try to find a link

In the meantime, you can download the '97 manual, and it will explain some of the questions you have asked about PCM comms

Its true the '96 electrical harness differs sightly from the 97

keep your eyes peeled, I will update this thread if I can

Its true a paper copy of the '96 manual can be had on USA Ebay, there is no electronic version, mine was photocopied by a auto electrician who owned a '96 from new, from the dealer copy. I downloaded his work on another platform, and re-uploaded it

Only the Fuel and electrical chapter differ from the '95 FSM

download them and have some good bedtime reading

electrical fault finding is very difficult, and I am a qualified electronic technician. You must be systematic

My mate who is a mechanic more than 60 years got a '97 XJ from a big auto electrical repair place, cause they could not fix it after one year. He installed another '97 PCM, and that fixed it
Export '97 have an '97 only immobiliser

 

try this link again now, I have fiddled with it, and it now says "unrestricted"

Please report on this thread if it works now !

If it does, all your dreams are answered, pinouts, wire colors etc etc

96 FSM ELECTRICAL - Google Drive

 

Your link works for me.
Good advice as well!