alternator question

[cliffsta]

My truck has the 50(ish) amp alternator in it from the factory. As it is now with just my Pioneer head unit and two 6x9s running off the head unit, if I have my lights and stereo and windshield wipers on the volts struggle to maintain, gotta rev the motor some to spin it up. So I figure when I order my 4-way amp and 2nd set of 6x9s next week I'll need a bigger alternator. I also plan on buying the foglight bumper from LMC down the road. So how big of an alternator should I get? Will 80 amps be too much? I don't want/need overkill (100 amps is probably waaay too much), so what do y'all think?

[hotrodhomi]

80 or 100 amp will work. They are regulated, so don't worry about over doing it.

[piecesparts]

Go with the 100 amp alternator AT The LEAST. I would even consider a 140 amp if available, especially if you are going to get some serious subs to go with your sound system. Do you have air conditioning in this truck? Think of all of the loads that could be on at one time, like windshield wipers, headlights, A/C, heater fan blowing high speed, stereo/amps, and the truck at a stop light---Idling.

Most alternators carry 35 amps at an idle speed. The rating on an alternator is at rpms above 1500 RPM. I am running a truck with stereo, and electric cooling fans, and with the headlights on it dimmed at the stoplights. I put an alternator on that is 140 amp at full charge and it carries 80 amps at and idle speed. Solved my problem.

[Russell]

I'm runnin a 105 amp alt from an 89 half ton in my 77 -- Huge improvement over the stock alternator, esspecially at an idle with my bright headlights, wipers, and heater fan blowing on high

Easy to install too

[cliffsta]

Well I won't be running subs, but I def. have ran the stereo, windshield wipers, A/C, blower, and my foglights (when they worked) and it would just drain it. So you don't think 80 amps is enough? I figure I'll just get one from AutoZone, that would be simplest.

[Russell]

Trust me man, get a CS130 alternator 105 amps, and lifetime warrantee for like 100 bucks If you think 105 amps is too few, then get a CS144, its a 140 amp alt found in police cars and some taxi cabs

Here is a link to everything that needs to be done to install one:

http://www.novaresource.org/alternator.htm

[piecesparts]

Eighty amps in an alternator is child's play in this day and age. If you want to be comfortable in the use of your electric systems go bigger. Think of anything that you might deside you want to connect to the truck later--such as KC highlites or a bigger stereo or an electric fan.

[GoobersBlueBurban]

If you are going to buy from Auto Zone you will be thankful for the lifetime warranty because you will be replacing it before too long. I would go with a 110-140 amp alt. and also might think about upgrading your battery to a gel cell battery (Optima or Exide Orbital).

[cliffsta]

Ok well I need more thoughts and whatnot. I don't want to spend 200 dollars on a 100 amp alternator when an 80 amp is half of that. I've calculated the worst-case draw of the stock electrical system, which at worst is 50 amps. The amplifier AT MAX output *600 watts* would draw 43 amps.... but God knows I wouldn't have it at max... half of that is 22 amps, so that puts me at 72 amps.

Keep in mind my battery is older than dirt and likely to die any day now, and the fact that the alternator is indeed, also older than me.

Couldn't I simply buy a bigger amperage battery than the stock and that would eleviate alot of my draw issues (on the alt. end)? I really do not have the money to pi$$ on 20 more amps....

[piecesparts]

Ok, I can see your thought process, however when those
subs hit on a heavy note and the headlights blink, you may want to upgrade to a higher amp. An eighty amp alternator is a really basic unit and 100 amps sometimes is not enough. GOOD LUCK

[cliffsta]

well again, i'm not putting subs in this truck. well i kinda started another thread about alternators (i thought this one was dead) so anyways... sorry for inadvertantly double-posting.

[gchemist]

I run a 120 amp alternator. Look for a 100 amp alt from Camaros 84-86.

[cliffsta]

Originally Posted by gchemist

I run a 120 amp alternator. Look for a 100 amp alt from Camaros 84-86.

That camaro alternator a bolt-in? Just plug n play?

[gchemist]

The 100 amp alternators with a v-belt bolt right in. I bought mine off ebay for $35. After the bearings failed, I had it rebuilt to 120 amps for only $63!!! That's cheaper than buying a 100+ amp alternator!!
Here is one on ebay http://cgi.ebay.com/ebaymotors/1984-...QQcmdZViewItem

[cliffsta]

Well here's the update. My dad called Mithcell's Alternator + Starter and then I went by. Said he'll rewind mine for 105 amps and rebuild it for 90 bucks, I just had to pull it and bring it in. Daddy's dropping it off on his way to work. The guy said he can build it more HD than anything I'll ever find aftermarker, and the cheapest 100-amp small chevy alternator I found was 100 bucks plus shipping. Sounds like a good deal to me.