I wouldn't connect a 3rd amp on that alternator, otherwise you'll risk your car stalling out, and you WILL get embarrassed. I only have 2 amps on my system, and can't even get the volume more than halfway up w/out voltage drops. I can't imagine what 3 amps would do. Wait to see how the module that you ordered works first, then if you feel like you have enough voltage, then add those additional subs and amp.