bryweb

I have a 2000 Cherokee (with a 96 motor, and viper coil swap), its my daughters trail rig.

I have a INTERMITTENT NO BUS NO START issue that seems to be aggravated when hot or low battery

After I swapped the motor in the Jeep sat for almost 2 years, finally we decided to register it and start using it, well first the gas went bad, so I had to drop the tank, clean it out, swap out to a new Fuel Pump Assembly, and pull all the injectors, check them and replaced as needed. YEAH IT RUNS

So off to register the Jeep and a brake caliper started dragging and ends up overheating, (2) new brake calipers with metal pistons, new water pump (was leaking), new HD ZJ Fan Clutch, new lower hose, Install missing fan shroud (manual fan) new Stant Thermostat and Premium Cap - Flush radiator, Fill with 50/50, Drilled (6) 3" holes in hood to release heat and it was nice and cool 205ish - well until today I charged the A/C and now it got hot (250F) at idle with A/C on (but that is another problem - I can deal with).

Also had an issue with it running like it had a 3000 RPM REV LIMITER as it would cut out if it got over 3000 rpms, after weeks of fighting it finally burned the PCM, replaced it with a Junkyard, then after that come to find out the Dodge coil a buddy gave me was bad, switched to a new coil and it runs great.

Now to the INTERMITTENT NO BUS NO START, So we thought everything was going great, we take it on a small 30 minute trail ride, my daughter wants to snap some nature shots with it and we shut it off, go to start - NO START, NO BUS, NO GAUGES, after about an hour of fussing with it, it seems to cool down, First I get the Temp Gauge working (but no volts or gas) and it starts, we jump in and shoot for home as fast as the 33's would go.... I do notice as we take off the battery gauge starts working after driving about 50 feet.

So we get home, shut it off and it starts right up - hmmmmmm, So the next day I go out and it starts right up and I drive it around, come home, shut it off to open the garage and it won't start NO BUS NO GAUGE - So now I am thinking its a HEAT thing triggering it. I start unplugging everything under the hood IAC, MAP, TPS, Crank Sensor, Cam Sensor, Oil Sensor, Temp Sensor, Fan, each item I would turn key off, unplug, turn key on, wait 15 second for "NO BUS" and it would appear. Give up, go to start it about 3 hours later and it starts right up.

So my daughter's boyfriend comes to town and she wants to cruise her cool jeep against my wishes, well damn if she does not drive it for 12+/- hours shutting it off and starting right up all day long. WTF

So I decide to leave the jeep sit for a little bit and the crappy battery drains near dead, but now I get the NO BUS NO START constantly with the low battery, So I try unplugging, key forward, check for NO BUS, key off repeat, I check the speed sensor at T/C and TCM under the dash, couldn't figure the NSS but I unplug the two big connectors for the transmission by the passenger fire wall, still NO BUS, I put a battery charger on the battery, check, still no bus, after about 20 minutes put the keep forward, here a fairly loud pop (like from a relay) and boom the gauges work and it cranks and starts.

So I toss a NEWER battery in, clean EVERY SINGLE Engine and Trans Plug with CRV automotive electric contact cleaner, use Di-Electrical grease and re-assemble, Charge the A/C in the driveway, go to drive it and realize I did not plug in the TCM, stop, plug it in, and it won't start, no gauges, no bus, no start. unplug trans computer and it starts, drive it shifting it manually, test drive it, stop at a buddies to pay him some money for a part I bought from him, hop in, its running 250... oh crap, shut off air, turn on heat and take off, in about a mile its down to 210, get home shut it off, plug in the TCM, try to start it, NO START NO BUS, so I think its the TCM, unplug it, and DAMN STILL NO START NO BUS

So two things I have not tried yet, I read somewhere where it was the dome light causing NO BUS so I am going to drop the light down and unplug it, also read Power Locks causing no Bus so I am going to try to unplug the door behind the driver kick panel,

Its done it with 2 different computers, and I have had 3-4 different crank sensors in it. When low battery NO BUSS I tried unplugging nearly everything. and still get NO BUS. I do notice Temp Gauge is the first to return and then it usually starts, and when it when the temp gauge come on I have heard a big click from engine compartment like a big relay just before.









Thanks,

Bryan

SouthSeaPirate

TL;DR :P
I will just tell you what fixed mine.
Driver door to body harness cracks, frays, and sometimes shorts. Right in the rubber tubing.
Hatch to body harness does the same.

There was plenty excess to pull and rewire for the door, but the hatch was too damaged and short; had to pull from an older XJ as all the NBS ones in the yard had the same issue.
Other problem spot was the KES in the dome. Connection was corroded as well as the board. It got to the point I could literally hook it up and guarantee 'no Bus'.

bryweb

Any and all ideas of where to look on the next round of "lets try this" helps, much appreciated.

SouthSeaPirate

The hatch I discovered on my own, all was found to be common during my research. All were my problem lol
Good luck man!