Alternator Charge issue on Escape

Dennis_H

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I know this is an Expedition Forum and I have one of those, but this forum is loaded with helpful advice and I can't find a similarly active Escape forum. Please delete if not appropriate. Think same issue could happen on Expedition with computer controlled alternator.

TLDR Description - After battery connection, all charging is good and charges at 14V. After a time of driving (between 5 and 10 min) the charge monitor signal disappears and the charge either goes to 0 (12V at battery) or runs away to 17V. Once battery is disconnected and reconnected to reset module, the monitor signal is again detected and charging is correct. I have tried different times of having the battery disconnected from overnight, to 2 hours to 5 min on last test.

Details:
Have an 06 Escape 3.0 180K or so. Normal maintenance items. Had alternator replaced 2 years ago. Is ECU controlled alternator.
2 weeks ago, son said dash gauges, radio, etc went away. Got it home and was charging at over 17V and cooking battery. Figured it was another alternator/regulator, so towed to mechanic since I'm not tackling that stupid alternator location in an Escape (have to remove axle, motor mount). Also bought new battery to put in since the other was at 3 years and had just been really cooked.
Got new alternator installed and 3 days later, same issue. Towed to mechanic and he said was probably ECU. I sent it off to Module Experts and they said it was bad and had to be replaced. (Not sure about that now)
Got new module in programmed for VIN, used Forscan and programmed keys. All looked good in driveway and GenMon signal was fine, 14V at battery.
Took it for a drive, and in 10 min, same issue and GenMon goes to 0. Luckily close to home. Disconnected battery overnight. Did same test where it was good for a while in driveway, but when driving, lose GenMon signal and goes into overcharge. Disconnected 2 hours, and worked fine on battery reconnect. Sat in driveway idle, reving motor, turning on AC and lights, all good. Drove 10 min on highway, slowed down to turn around, and same GenMon loss and overcharge condition. Pulled battery cable off for less than 5 min, and drove home with it fine. Seems to be ECU issue again since just powering it off seems to fix it? Or is it resetting something in alternator when power is lost? Here is a pic of Forscan when Gen Mon goes away and crap happens... This was at highway speed, slowing down to turn around, and nothing.

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When I take off battery cables, it seems to be OK. Here is a graph of what it looks like when charging fine in driveway, and starting the drive through neighborhood.
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I don't know where else to check. Any ideas on troubleshooting this thing?

Thanks and delete if not appropriate to ask here.
 

riphip

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May need another regulator or even alternator. Should not be charging more than 14.5v at most. Will start burning out electronics.
 
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