Possible Alernator Issues
 

I think that my alternator is starting to go on me. When I go in my car this morning I turned the heat to max and I turned on my defroster and the interior lights dimmed and my headlights dimmed for a second. When I rev my engine or start accelerating, everything operates normally. I'm also noticing a rough idle so I'm thinking my injectors aren't being supplied enough voltage. Isn't the battery indicator in the cluster supposed to go off if my alternator isnt supply enough current? I was thinking of getting a HO alternator soon enough anyways.

check the grounds and battery connections

Nah, if it's supplying power it won't light the battery light... obviously just not enough though.

Check your running voltage.. should be about 13.5V or above.

Otherwise getting the alt checked and properly load tested is usually pretty cheap at a shop.

With the fans blasting all the way and the defrost on my car has been acting this way for 3 years. I wouldn't worry about it yet.

Your car doesn't necessarily charge the battery at idle. When you load it down with the defrosters at idle, you are probably discharging the battery,

Should I get roughly 13.5V at idle with my defroster and heater on full blast?

So I've found out that my alternator is crapping out on me. It's getting pretty hot to the point where you can't touch it for long. Whats a good amp rating for a High output alternator? I'm running a subwoofer and an amp already and I intend on getting another amp for my speakers. Also would an overdrive pulley decrease HP?

I have a 04' with stock Alt and my car has lower heater power and light power at idle rather than 1K+ rpms even in 1st gear. This has been going on since I bought it a year ago, and I run 2 12"s constantly. I would agree your Alt. is probably going bad, but an overdrive pulley sounds out of mean for your application, I personally would get a HO alt as I will be replacing my stock Alt with one. Funny thing is I have seen TONS of stock Alts. and OEM replacements on many vehicles handle heavy, heavy loads....I'm talking about 4 12"s, 2 1K amps, LED's lighting floors, subs, dash, vents, strobe in headlamps, all running OEM replac. under the hood without illegal dimming of ext. lights.

Well I guess it depends on the car and the stock alternator amperage rating. I know the 3400's alternator is 105 amps. I'm just wondering if upgrading to something in the 170 amp range is too much. I'm going out tomorrow to get the alt changed just to get it outta the way. Just thought I'd do some last minute research.

http://www.powerbastards.com/products.asp?cat=2325

That is listing a 220A for my 04' 3.4L, So I'm guessing it would have NO problems with a 170A HO Alt.

It would take several hundred LEDs in a car before your alt even noticed the current draw from them.