My 02 montero sport 3.0L seemed to have a dead battery even though battery is 1 month old. I jumped it off, it cranked fine. Turned lights on, put in reverse and took foot off brake and it cut off with no power. Jumped it again and kept engine revved up. When brake depressed lights blinked. I was able to drive it home but had to keep foot on accelerator. When I would brake, lights would blink. Got it home and let off accelerator and it died immediately. No power at all, no interior lights, horn, nothing. I hooked up battery charger and it shows battery is fully charged. Any suggestions????

 

invest in a multimeter and a new battery.

 

Alternator is possibly bad. Not charging battery. I would take that batt back to where you got it and have it tested/ replaced