2.5L ('98-'01) '99 2.5 PCM issues?

[Bsmalone]

My 1999 ranger 2.5 manual 2wd is having some issues. 1. Interment missfires and low power at any point in the power band randomly. 2 Oil pressure gauge bounces. 3 idles poorly and pops randomly while idling. 4 if the AC is running and the power steering is beinf used it causes it to die. As if the ELD isnt working. 5 long term fuel trim is at 30%. 6. Sounds like at different points the igniton timing gets retarded and the power suffers.

These are all things that have been wrong for awhile but ive yet to check but today it got worse.

Today it died while in neutral while idling. When i tried to start it i had no ignition. Got it pulled home and checked it out to find the PCM fuse in the interior fuse box was blown. I replace it and it starts but dies after a minute because the alternator wasnt chargung the battery. I charge the battery and hook it back up and it has no spark again. The new fuse was blown. And the alternator isnt getting a signal to turn on.

Ive called it a night for today but i feel like my PCM had shat itself and needs replaced, does that seem right to any of you. Any help is appreciated.

 

[Fredness]

Sounds like you narrowed it down...

 

[RonD]

Not the PCM, for sure

The PCM fuse(fuse 8), powers most of the engine systems, including the 4 injectors, and 3 or 4 solenoids, and then the O2 sensor Heaters, but via fuse 13, 15amp

A short in any of which could cause PCM fuse to blow

You need a Volt/OHM meter
Pull out fuse 8, also pull out fuse 13, these are both in engine bay fuse box
Test which side of #8 holder has 12v
You want the OTHER side of holder, thats the Load slot
Switch to OHMs
Leave fuse OUT
Test OHMs on Load slot to Ground, should be N/C(no connection) or very high number

Turn on key, PCM relay will close
Retest OHMs, should be under 20 from solenoids and injectors, but NOT under 10, or 0(dead short)

If ohms are low then you will need to start unplugging connectors on solenoids, but try just moving wiring harness around, could be a short where a wire has rubbed thru