Power / stalling problem

[MKIIIChucky]

I got home the other night n as I was lettin the supra idle be4 I turned it off, n it started trying to stall out . As that was happening I saw that my safc turned off , then i hit the gas n it turned back on , as I hit the gas n reved the engine the lights for the arrows on the safc were diming out ......... Its not the battery couse i just replaced it when I did the starter , U think it might be the altinator going ?? any help would be great , thanks ! Chuck

[MKIIIChucky]

Over looked the wiring on the ecu to the safc n everything looks good there , but the arrows on the safc still dim out when I hit the gas ,+ it still trys to stall out when its at idle, I checked all the battery n altinator wires n there all on nice n tight soo theres no loose connections .... Any help would be very thankful !