904 curcuit

[chainsawjunkie]

hi,, new here and looking for help, my issue is as follows, my explorers battery died awhile back, replaced with a new battery. didnt help the problem so tested the alternator , all tests indicated a "no charge" situation. Bought a rebuilt alternator, still no charge. At this point I get confused. do more research, pulled alternator off and have it tested. tested good. changed battery out with a known good one, still no charge. seems I have no signal or trigger voltage from the 904 curcuit (LG/RD) wire. have battery voltage at the heavier (RD/GY) wire and battery voltage at the output lug. tested the lg/rd wire for continuity back to the PCM, wire is good. So my question is: am I looking at a faulty PCM?
any input would be appreciated.

 

[chainsawjunkie]

Update 904 circuit,, after much research, probing, testing and frustration the "no charge" problem is solved.
Just some helpful info for someone who may experience this problem.
Decided to attack my wiring issue again after a "cooling off" period, ran all the same tests, this time I had no voltage on the heavier wire that connects to alternater via the 2 wire connector, checked fusible links located near PJB, peeled back insulation to reveal massive corrosion under said insulation. cut and stripped everything back to good copper, soldered and shrink tubed it all back together and viola,,, battery voltage to connector, fired up the vehicle and all is well in the world,,,,, charging at 14.2 volts.
Moral of story,, even though I had voltage to the Alt. prior, I dont think the wire was carrying the proper load.
Anyway something to check if you experience a "no charge" situation and have replaced battery and alternator