Looking for a reliable high output alternator for my 05 suburban z71.

anickode

Adventurer
The problem with high output alternators is that they are usually just rewound OEM units that take a LOT of RPMs to put out their rated power. They Also heat up really quickly Because all that extra generating capacity is packed into such a tight space. This is especially true of small case alternators with internal fans. IMO, The BEST option would be a second BIG battery and a second alternator to charge it, independent of the rest of the vehicle's systems.

GM Fleet parts may offer an OEM high output alternator that will fit... they offer specialized police and ambulance options that aren't available on normal models. Ambulances in particular tend to have massive charging systems that are designed to support loads of medical equipment, radios, lights, climate control, etc, with the engine at idle.
 

xbox73

Adventurer
Ok. When the traction control or abs kicks in the voltage drops.

Make sure the voltage is really dropping & the gauge is not misleading you. On my '89 Jeep, the more accessories I turn on, the more the factory analog voltage gauge drops, to the point that it almost shows 9V & in the red part of the gauge graph with all accessories on. However, I wired a 8 gauge cable directly from the battery to a Blue Sea fuse block, for running some accessories, and a digital voltage gauge connected to that shows a rock steady eddy 14.4-14.5V. Not sure exactly why the factory analog voltage gauge reads so low, maybe the gauge of the factory wiring to the gauge.
 
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xbox73

Adventurer
Interesting .... 14 posts and no one recommends any brand or capacity of alternator

I've been through the alternator hassles - and I've come to Powermaster alternators. They seem to be the best balance of price and quality. Should you want a greater amp capacity, alternator come in frame sizes (e.g. 10si, 12si, etc) thus once you determine what frame fits, you choose your alternator based upon that physical size. Power outputs vary widely, but you'll find that about the biggest you'll get for your GM is in the 200 amp range.

I run a winch and dual air compressors on my H3 - I never run out of power.

Avoid the ebay alternators at all costs and never buy a one-wire when you do a lot of idling (I'd say never, ever a one-wire, but then the trolls would descend... but really, it's so easy to run a resistor and wire to control the alternator, that only the most helpless mechanics would use a one wire)>

I too run a Powermaster alternator (140A on an '89 Jeep with SBC motor) and came to the same conclusion as you did w.r.t. best balance of quality & price. Happy with it so far.

I tried a DB Electrical alternator on a diesel Ford Excursion, and that alt died within a month, may have been junk right out of the box. Replaced that with a NAPA alt with lifetime warranty, as I was stuck in a small town with just 1 auto parts store, and they just happened to have the one that I needed in stock. Happy with that so far, but may upgrade to a higher output alt (or go to a dual alt setup, since 7.3L PSD ambulances & work trucks were available from the factory with a dual alt setup), and just keep the NAPA as a spare.
 

snowblind

Adventurer
Interesting .... 14 posts and no one recommends any brand or capacity of alternator

I actually posted a brand and links to the product page: I will post again since it appears that this brand in little known outside of car audio

Mechman Alternators. Viewed by many as the best in the car audio business. 2-year warranty. -> http://www.mechman.com/alternators/c...uburban/05-14/

240amp Model @ $350 - 140+ amps at 600 RPM engine speed, 240+ amps above 1800 rpm.
270amp Model @ $450 - 165+ amps at 600 RPM engine speed, 270+ amps above 1800 rpm.
370amp Model @ $700 - 200+ amps at 600 RPM engine speed, 370+ amps above 1800 rpm.

Napa has a 200 amp model online for $254 so the 240amp mechman model does not seem unreasonably priced.


Matt
 
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kojackJKU

Autism Family Travellers!
Make sure the voltage is really dropping & the gauge is not misleading you. On my '89 Jeep, the more accessories I turn on, the more the factory analog voltage gauge drops, to the point that it almost shows 9V & in the red part of the gauge graph with all accessories on. However, I wired a 8 gauge cable directly from the battery to a Blue Sea fuse block, for running some accessories, and a digital voltage gauge connected to that shows a rock steady eddy 14.4-14.5V. Not sure exactly why the factory analog voltage gauge reads so low, maybe the gauge of the factory wiring to the gauge.

no, its really dropping, it has shut off a couple of times.
 

pappawheely

Autonomous4X4
I too run a Powermaster alternator (140A on an '89 Jeep with SBC motor) and came to the same conclusion as you did w.r.t. best balance of quality & price. Happy with it so far.

I tried a DB Electrical alternator on a diesel Ford Excursion, and that alt died within a month, may have been junk right out of the box. Replaced that with a NAPA alt with lifetime warranty, as I was stuck in a small town with just 1 auto parts store, and they just happened to have the one that I needed in stock. Happy with that so far, but may upgrade to a higher output alt (or go to a dual alt setup, since 7.3L PSD ambulances & work trucks were available from the factory with a dual alt setup), and just keep the NAPA as a spare.

I am another who is very happy with Powermaster Alternators. One of the most trouble free upgrades I've done. Bolt it on and forget it.

 

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