I bought a 96 xj 4.0l auto. The PO removed the alternator. He cut the wires to the alternator on removal.
It was a bad alternator.
I thought no biggie throw alternator back on to have power accessories back with the serpentine belt

Jeep started before alternator install.
Now the jeep cranks no start after alternator installed.
I removed the alternator wires to keep it the same before install.
Tested the CPS it read 400 ohms figured it was bad or going by chance.
New one installed reading Open.
Same thing crank no start.
Now my thought is I must of messed up the alternator wiring placement.
I have Dk green/ Orange and Dark green.
My engine schematic shows the DK/GR orange to the :
auto shut down relay
PCM on Pin C12
Ignition coil
fuel injectors
O2 Sensors

The DK goes to PCM
If I put the wires backward could I fry the PCM?
(the two small post on alternator)

 

I tested the 5v reference voltage at the TPS, CPS and have 5.2vdc
I'm lost at this point any help?

 

Check all fuses inside and out. Alternator controlled by Computer .

 

I have checked the fuses for some time. Switched the fuel pump relay, and ASD relay.
I cycle the key while having the test light on the Green/orange wire and see power when cycled and cranking when connected to the Green/orange wire at alternator, and First fuel injector, So I believe my ignition circuit is good.
I took the spark plug wire off the 2nd cylinder put a bolt in the wire and had my son crank over, It shocked me. So I think I should have spark.

New CPS
Fuel gauge reads normal, CPS reads open.

38 PSI at fuel rail when key is cycled.

I'm thinking now it must be fuel? Is it possible to have clogged injectors?

 

Do you have a noid light to see if an injector is cycling? It's hard to believe they could all fail at once. Have you ever heard it run?

 

It did run is what is aggravating. I drove it into the shop.
My plan was install the alternator just to get the serpentine belt going.
I did not drive it far as it did not have power steering or brakes.
I do not have a noid light. I have a simple light tester to see if I had power to the injectors.

 

Check the c107 connector for dirt and corrosion. Its right by the battery, rectangular, black with red locking tab. Clean it up, then check for continuity from the ign coil fuse minifuse (10amp?) In the PDC to the plug that goes to the coil. If it shows high ohms, then test from the 107 connector (female side) to the same fuse terminal, then from male side of that connector to the coil. This will let you get an idea of where the issue is if there is one. If the wiring from the male side to the coil shows high ohms, the issue is likely the splice/junction by the alternator.

 

Ps. Maybe check the distributor pickup and it's wiring. I'd start looking at stuff where you worked on it last, maybe it's something that got missed. Since that was the alternator, I'd check the harness junction by the alt, distributor, distributor pickup, make sure your coil wire is seated properly and didn't get knocked, what about the ground that goes from the alt to the coil bracket?

 

I think I will look at the easy stuff.
Check the plugs, wires, distributor.
I have spark, but may not be enough.
I put a new Ground wire from the block to the alternator.
I will sure check the connector again. Do a resistance check. Maybe use some electronic cleaner on the contacts.

 

https://www.cherokeeforum.com/showthread.php?t=186515.

I just dealt with a tough no start situation myself, here's the thread from it. Everyone on this forum it seems chimed in and provided me with tons of good info. DFflintstone posted links to some videos that really helped. They are on the 2nd or 3rd page. Anyhow, here's the thread link https://www.cherokeeforum.com/showthread.php?t=186515

 

IT"S RUNNING!
I stopped by the local auto part store on the way home. Picked up some plugs and wires. My thought was I have fuel at the rail, I have spark. All the wiring tracked down. New CPS.
The Previous owner did not run the jeep for some time. I should of known to drain the fuel and start fresh.
I believe while I was working on it I fouled the plugs with old fuel. Or combined with old plugs and wires to begin with. It started and ran, but i didn't' get a chance to drive it far with out any power accessorizes.
To my surprise I cranked the key once and fired right up. It's running very strong. Very shocking.
I thought for sure I messed up the wire order when putting the alternator wires on. Just by chance fouled plugs.