so i took my 99 runner out to a local 4x4 play area and after going through mud/sand pits everything was fine but i as i was driving home i stopped because my check engine light went on. so i tried to turn the car back on and it wouldnt start. i called AAA and got it towed to my house. the next day i talked with my friends about it who said they had the same problem and it was the alternator/battery. so i plan on doing much more off roading and i was wondering if there are any addons/mods i could do to my truck that would make it able to take some beatings without having it to be towed every time. thanks,