88 xj no power to anything but starter and radio
 

so ive had an issue lately with my cherokee running rough when cold and running rich all the time.
but today it got severely worse, on my way home from work i noticed the volt meter was slightly less than usual. like 11volts. so i decided to do an experiment and turned both my e fans on, my blower motor, and my headlights. it dropped severly almost into the red. i turned off the accesories but it was too late. it started bucking and trying to die. it then did what i think was a backfire through the intake and blew the map tube off the side of the throttle body. i put it back on and started it. it ran okay but rough. it stalled a few times on the rest of the way home and noticed anytime there was an intermitten load on the battery the rpms would raise a few hunded then drop back down. when the jeep was off and i had the hazards on the rpms would shoot to 5000 then jump back down when the flash stopped. so its was jump jump jump along with the flashers. when the jeep was off the coolant temp sender was shooting past the red unless the key was turned. now the jeep wont start and i have no fuel, spark, headlights, dashlghts, anything but acceserys that are not ran through the ecu. so i have my e fans, my starter and my radio. im gonna go out on a limb and guess my ecu took a dump on me?
heres what ive done to the jeep latley.
new starter, new tps adjusted properly, cleaned throtte body and iac, cleaned intake manifold, new 4.0, cleaned grounds, c101 elimination, new cps, new iat, done cruisers ground test and it tested good last time i did it(yesterday)746 injecors, fuel pressure test tested great.
idk what to do here guys, help me out!!
(i know you have some info for me cruiser, lol!)

Wiring
Alternator
Battery

Battery cables are new, 2 ga. Cable
Alternator has maybe 500 miles on it. Battery has 500 miles on it and it's a optima yellow top.
The jeep cranks fin I just don't have fuel, spark or any accessories that run through the computer.
I'm gonna try to pick up an ecu Tomorow I think. I've really gotta get her running guys! I've got an important toy drive/wheeling event to go to at my local ohv park this Saturday

Also check the fuse box, in my 89XJ the fuse box was a nightmare, causing all kinds of issues, and actually I end up removing the OEM and installing a new one, this cured 99% of my electrical problems, the other problem I did have was the ignition switch.

Discard those ones out, check voltage is getting in and out as it should

So I just found out when I try to turn my e fans on(wired to my own fuse block off the battery) the relays just click. The switches are wired to the fuse block though so that might make sense if there the power switch to the relay is through the ecu where I plugged it into the fuse block. I pulled the ecu and it looks good

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Alright, so I decided because I have a renix jeep, I should really clean my grounds. I found black paint behind the dipstick mount where the engine remanufacture's painted. The ring terminals on the grounds were gross too.
I wire wheeled the block, the dipstick mounting bracket, all the ground terminals and even wire wheeled the bolt that holds them all on. I then costed them with copper flake greese(anti seize) and bolted them back up. I then found the rear ground strap completely loose...(problem found?) Just for good measure I wire wheeled the ring terminals and the mounting areas. Gave it a good snug on there and crossed my fingers.
She started right up!
Now I can go to the event tomorrow and all is good.
Idling a little higher on a cold start but still low. It does seem to shift better...lol

Good to hear.

I would suggest running an extra ground strap eventually (one of the beefy ones you can find at an auto store, not another braided pos) on the right side attached to a rear fuel rail bolt. The dipstick side I replaced with a bigger one to the firewall. Easy, cheap insurance for the under engineered grounding.

You can kinda see them on mine in this pic

I just left the old strap on the back of the engine and didn't even bother cleaning it.

Diddnt think about putting another there! I was gonna put one made of 4ga. Cable from the dipstick grounds to the unibody rail. When I'm doing that I'll put another on the fuel rail bolts.
Thanks man