I have a 97 ranger 3.0 2wd and it keeps blowing the pcm fuse
I replaced the fuel pump and I replaced the pcm relay but when I turn key on the fuse blows I pulled the relay out and replaced fuse turn key on fuse does not blow I checked all major grounds and all look good. Need help desperately.

 

Welcome to the forum

You replaced the fuel pump and THEN PCM fuse(#13, 30amp) started to blow?
They don't have anything in common
Fuel pump is powered by fuse #12, 20amp

Is there any other clues or changes you did just before the PCM fuse started to blow?

PCM relay powers all these things...................
The PCM, engine computer
Wide open throttle relay
Fuel Pump relay(not the pump)
Purge flow sensor
All 6 fuel injectors
Fuse #3 in engine fuse box, that's for the O2 heaters
EGR solenoid
Cam position sensor
MAF sensor heater
Idle air control(IAC) valve
If automatic trans then it also powers all 6 solenoids inside the transmission

I think thats it, lol

Unless you have a pocket full of fuses best bet is to use an OHM Meter to test for short to ground while you unplug each device above one at a time
But it could be a shorted wire, not a device, so unplugging all devices and you may still have the short to ground