Serious voltage drop

[CaptAhab]

Ok so battery light comes on on the way to work. Head over to advanced after seeing that one of the batteries (cheap duracrap/Advancenothing brand) was leakin. So I drop 400$ on a good charger and two optima red tops.

go out to the truck to start her up and it was cranking but no start. Tried again and same thing just more sluggish. So I replace the batteries and it starts, slower then usual and the battery light is still on. I drive it around a bit (15 minutes) and it will come on at idle and shut off under heavy load.

truck has a very slight cycle, as in it sounds like the voltage is dropping and kicking the alternator back on. I am thinking the voltage regulator is messed up on the alternator.

Any other ideas?

[bigcountrysg]

I say the alternator needs to be replaced. If your battery light is on most likely is caused by a faulty alternator.

[mudracer]

I vote for the Alt.

[CaptAhab]

Any good brands?

I was kinda thinking of fanless one. Guess it really doesn't matter but the other question I had is how hard is it to upgrade to a dual alternator setup? I know some years of my truck had that as an option.

[cchase]

check the conection on the alt. mine came lose and did the same.