RoadyRider
New member
My 2000 Expedition has suddenly developed a weird charging issue. During normal driving, everything seems to be working fine. If the engine RPM gets to about 3500 (passing on the freeway, hard acceleration, etc.), the lights start to dim and at about 3800 RPM, the battery light comes on. Once you back off the accelerator and the RPM's drop, the lights come back up to full illumination and the battery light goes out. I've been doing my own repairs for more years than I care to count and this is a new one for me. My first thought is that the alternator and/or the voltage regulator are failing but it would be the first time I've ever seen one stop charging based on high RPM's. Any relevant thoughts would be appreciated.