Rockcrawler Alternator

[yellowchevy]

I need some guidance/advise from the members that know more about this than I do.

Being my rockcrawler is drivable and moves under its own power it's time to work out some of the bugs.

Currently it has the stock alternator out of the 1988 Chevy suburban, 90 amps if I remember. I'm having the problem of killing the battery with just the essential items running. Last summer with electric water pump, ford tarus fan, and transmission cooler fan it will kill the battery. I've got a single Odyssey battery in it and was planning on installing a second one.
I've thought about dual alternators but I don't have the space for it in the engine bay.

My electrical list is as follows,
Electric water pump - 50GPM 6amps
Ford Tarus fan - 90-100amps (at start up from my reading)
50 - 60 amps (running)
Power steering and transmission oil fans - 13.5amps each
5 front & 4 rear 55 watt lights - 4.6amps ea
2 - 3" LED brake lights
2 - 2" LED backup lights
5 - analog summit gauges
Warn Powerplant winch with air compressor - 94-451amps
Obviously the winch will suck the battery down and the alternator will charge it back up.

I've been looking at mechman alternators and XS performance batteries but they aren't cheap. I've got a few options,
240amp - $349
270amp - $449
370amp - $749
XS1400 battery - $260

From talking with the salesman he suggested the 370amp alternator, 3 XS1400 batteries, and possibly a voltage regulator. I don't feel 3 batteries is needed, just 2. If I were to get the 370amp alternator and 2 XS1400 batteries it would still be $1270; not including shipping. I know you've got to pay to play but I feel that's alot of money for electrical; I still can't get over the alternator prices.

Anybody out there deal with alternators before or have something else I could do?

Thanks in advance,
Yellowchevy

 

[Chevy1925]

those reman GM alts are junk for those year turcks. i went through 4 of them in my samurai just running the factory TBI system and stock headlights which is all of 30amps total and i was running a GM 90amp two wire alternator.

My advice, take it down to a good rebuild shop and have them work their magic on bumping the power up. will usually cost you much less than a new one and it will last much longer. i wound up putting a factory sami alternator back in. no issues since at its factory 50amp rating

 

[mackthehack]

I'd try running two batteries. I know the Optima's are good and sealed. Another good battery which I run in my Dmax are Exide Orbital's. Equivalent to Optima.

X2 on what James said about the crappy rebuilt GM alternators.

 

[chevyburnout1]

Also make sure the drive pulley is correct size. Not saying that's the main problem as you still need a bigger alternator, but I had the same issue on my '77. Turns out the crank pulley was too small and wasn't driving the alternator hard enough at idle (where it runs most of the time).

 

[AKlowriderZ71]

I don't know if this will work for your application, but a friend of mine has a 250 amp alternator for sale. http://www.performancetrucks.net/forums/gm-parts-classifieds-23/250-amp-alternator-sale-516543/

 

[rennat_2006]

Why are you running so much electric stuff like the water pump and all of the fans? Could you run a regular water pump and fan to get arid of some of the load?

Might try to fit a dmax alternator in there, they are 140 amp if i remember correctly and it fit fine just needed a 1" longer belt on my 2000 4.3l with all stock accessory brackets. They come in the gasser suburbans also with the heavy duty electrical system. Way better alternator than the 90's junk.

 

[Chevy1925]

I'm pretty sure his rig still uses v-belts still which makes upgrading to something newer harder

 

[THEFERMANATOR]

Be careful of alot of the high amp alternators, I know it sounds bassackwards but alot of the high amp units actually put out less at idle. The AD244 like comes on the late model DURAMAX is a GOOD option as they can put out ALOT of amps at relatively low RPM's. If your still running V-belts, you will want to ditch them. Once you start getting up over 100 amps you get to the point that a single V-belt just can't handle the load, and even dual V-belts is being pushed. The CS-144 and AD244 would both get my vote at 200-250 amps with an external rectifier set-up. High output at low RPM's is going to create ALOT of heat, and your going to want it away from the alternator and in an area where it can be controlled.

 

[yellowchevy]

Why are you running so much electric stuff like the water pump and all of the fans? Could you run a regular water pump and fan to get arid of some of the load?

Might try to fit a dmax alternator in there, they are 140 amp if i remember correctly and it fit fine just needed a 1" longer belt on my 2000 4.3l with all stock accessory brackets. They come in the gasser suburbans also with the heavy duty electrical system. Way better alternator than the 90's junk.

I have to run the electric water pump and fan due to not having enough room up front; when I built the chassis I didn't push the front end out fare enough .
I need the other two fans for transmission and power steering oil cooling.

Being my alternator is 2 wires would I be able to switch to a single or 4 wire connector? Just curious.

Yellowchevy

 

[yellowchevy]

Be careful of alot of the high amp alternators, I know it sounds bassackwards but alot of the high amp units actually put out less at idle. The AD244 like comes on the late model DURAMAX is a GOOD option as they can put out ALOT of amps at relatively low RPM's. If your still running V-belts, you will want to ditch them. Once you start getting up over 100 amps you get to the point that a single V-belt just can't handle the load, and even dual V-belts is being pushed. The CS-144 and AD244 would both get my vote at 200-250 amps with an external rectifier set-up. High output at low RPM's is going to create ALOT of heat, and your going to want it away from the alternator and in an area where it can be controlled.

Fermanator,
Thanks for you post, I had forgotten about new style alternators for some reason.

I'm running the stock 4 groove serpentine belt which is better than the V-belts. I'm really liking the AD244 but looks like the CS-144 would be easier to mount but I'll have to look at it in person.
It also looks like the pulley has 5 grooves not 4 so I'd have to swap out my crank pulley?

I'll have to continue to do more research in what I'd have to do to mount the AD244 or if the CS-144 would be better; I ultimately want an alternator that has high out at idle.

Thanks everybody for you help and keep it up.

Yellowchevy

 

[THEFERMANATOR]

You can run a 4 groove belt in a 5 groove pulley, but not the other way around. The CS144 and AD244 are both pretty much the same size. The difference will be that the CS144 can be had with a 12 and 6 mounting position whereas the AD244 is going to be the 12 and 4 mounting position that is common today. There only real difference is the AD244 has an internal fan, improved rectifier, and regulator setup, and the CS144 has an external fan, old style rectifier, and regulator. Both can be had with an external rectifier for improved heat control, and both can provide 80-90 amps at an idle in stock form.

I haven't ever dealt with this company, but he has alot of options for high amp units.
http://alternatorparts.com/

 

[yellowchevy]

You can run a 4 groove belt in a 5 groove pulley, but not the other way around. The CS144 and AD244 are both pretty much the same size. The difference will be that the CS144 can be had with a 12 and 6 mounting position whereas the AD244 is going to be the 12 and 4 mounting position that is common today. There only real difference is the AD244 has an internal fan, improved rectifier, and regulator setup, and the CS144 has an external fan, old style rectifier, and regulator. Both can be had with an external rectifier for improved heat control, and both can provide 80-90 amps at an idle in stock form.

I haven't ever dealt with this company, but he has alot of options for high amp units.
http://alternatorparts.com/

I should have thought about that before posting, duh .
There's a guy in Olathe KS that can modify alternators that's I've talked with a few weeks ago. At the time I was talking about modify the SI alternator I have on right now but he as others have said isn't the best platform to work with. But with the new information I now have I'll be giving him a call again in seeing what he can do with a CS144. My buddy has a CJ7 and used the same guy to increase the output of his alternator.

I came across that company before in my searches and will being looking at them as well.

Thanks for you help,
Yellowchevy

 

[THEFERMANATOR]

The CS144 will blow away anything that a 10 SI could even dream about doing. Whatever you do though, go with the external rectifer to help control the heat better since you will be spending so much time at high amp draw at low RPM's.

 

[yellowchevy]

The CS144 will blow away anything that a 10 SI could even dream about doing. Whatever you do though, go with the external rectifer to help control the heat better since you will be spending so much time at high amp draw at low RPM's.

Does the rectifier mount elsewhere or is connected directly behind the alternator? I thought it was mounted on the alternator but I can't remember.

Do you feel I need a volt adjuster to increase my voltage when I use the winch or don't bother?

Yellowchevy

 

[THEFERMANATOR]

Does the rectifier mount elsewhere or is connected directly behind the alternator? I thought it was mounted on the alternator but I can't remember.

Do you feel I need a volt adjuster to increase my voltage when I use the winch or don't bother?

Yellowchevy

They make an external rectifier with it's own fan mounted in an enclosure to help deal with heat better. they make them with the stock internal ones, external ones, and the remote ones. I don't see a need for a step up box, your winch should be able to keep up just fine so long as you keep a good steady 14-14.5 volts to it. Also you can hook up the voltage sense wire directly to the battery so it will keep the batter yat 14-14.5 instead of the output lead from the alternator.