From the brand
Product description
Why You Need 255 Amps (Yes, Really)
Stock alternators were designed for:
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Factory lighting
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Basic HVAC
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Stock audio
They were not designed for:
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Snow plows
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Winches
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High-output audio systems
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Auxiliary lighting bars
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Refrigeration units
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Emergency or service equipment
A 255-amp alternator provides:
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Massive charging capacity at idle
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Stable voltage under extreme load
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Faster battery recovery
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Reduced strain on batteries and wiring
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Longer battery and electrical component life
This is how you stop chasing electrical gremlins.
Built for Heavy-Duty Abuse
The OEG Parts High-Output Alternator features:
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Heavy-gauge copper windings for sustained output
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Upgraded internal components for thermal control
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High-capacity internal voltage regulation
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Precision-balanced internals for durability
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OE-style mounting points and connectors
This is not a reman “hope it survives” unit. It’s built to work.
Charging System Reality Check
Once the engine is running, the alternator is the primary electrical power source. If it can’t keep up:
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Batteries die early
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Voltage drops cause module issues
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Electronics behave unpredictably
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You end up replacing parts that aren’t broken
A properly sized alternator fixes the root cause, not the symptoms.
Why Buy from Pro Street Online?
At Pro Street Online, we don’t sell underpowered solutions:
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Vehicle-specific fitment
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Correct amperage for extreme electrical demand
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Brand new — not remanufactured
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Built for work trucks, tow rigs, and real-world abuse
If your GM platform actually works for a living, this alternator keeps it alive.
The OEG Parts 255-Amp High-Output Alternator is the right answer for GM trucks, vans, and SUVs running 6.0L, 6.6L, or 8.1L engines from 1999–2015. Massive output, OE fitment, and zero patience for weak charging.
If your truck needs power like it needs fuel — this is it.
Mr. Perez –
So far it’s working good for my electric fan conversion no winding noise like others said, and the same belt fit back on perfect. The voltage does drop a little under the 14 only when both fans kick on high with the AC compressor but goes right back up nothing to be concerned about. we’ll see how long it lasts. I’ll update if anything changes.
Xavier M. –
Puts out plenty power for my system! I would recommend swapping to a smaller pulley if you run high power while idling.
Heather Dufresne –
Installed the first one that was sent to me and it was defective did not work. Seller did send me a replacement very fast. The replacement did not work as well it was defective like the first one although the second one did work to start the vehicle the voltage never raised to the correct charging . Ended up having to go to my local parts house and get a good alternator . That was over a month ago and still have not gotten my refund . I have sent both alternators back over two weeks ago with no response or answers! We were these are not going to push the rated power. Do yourself a favor go with a better brand in the long run I would’ve save myself a lot more money just for the one I had purchased a good one.
Shoe –
Love this high output alternator. It is amazing powerful for snowplowing late nights. Durable and will stretch your battery life. perfect replacement for my truck.
Amazon Customer –
Update: First one has failed at 1 yr 3 months. I went ahead and ordered a second one that I installed today and is working fine. Highly suggest the square trade warranty. They made it good. (Full disclosure, this alternator got a lot of use so this wasn’t totally unexpected that there would be a fail within a year or two. Super easy to replace, so not a big deal for me)Worked for what I bought it for. I am hopeful that it will have good longevity. I added a second battery and an isolator to run a 1000 watt pure sine inverter. Has no issue bringing a deep cycle battery back to full charge very quickly. You will need the longer belt that goes with the 160 amp stock alternator option. This was installed on a 2000 Chevy Silverado. Battery and inverter will run a 350 watt space heater for about 30 minutes. After draining the battery beyond operating the inverter it took the alternator about 15 minutes to fully recharge it with normal driving. I would recommend tuning the idle speed to at least 800 rpms if you want this unit to hold in the 13.5-14.5 range with a heavy load on it. I have found that it will run the heater on 750 watt mode indefinitely and keep everything else going at about 13.8 – 14.2 volts as long as the engine is running 800 rpm or higher. Full wiring disclosure: 1/0 from auxilliary battery to isolator. 1/0 from isolator to primary battery power tap. 1/0 from power tap to alternator. I left the stock power system as is. I ran 4 awg from the auxiliary side of the isolator to the inverter. I protected that run with a 200 amp breaker/disconnect at the isolator.
Brandon –
Biggest down side is alternator pulley size, I had to swap to a 49mm pulley from power master (model 115) only pulley smaller than that is made by MARCH – with upgraded power and ground wires and new optima redtop and idle speed of 520 to 580 (depending on AC) at night coming to a stop light or sign everything would dim and voltage gauge dropped horribly (even with the “s” sense wire in place)Had a turner turn the idle up to 700rpm along with the power master pulley and things seem to be good to goI have not had the unit load tested or put my amp meter on it yet with everything on
Hayden Titman –
Works great! Fit perfectly. If your having any power loss issues this will for sure fix the problem. (2003 gmc 2500, 6.6, duramax.)
Kindle Customer –
If I could give 0 stars I would. I bought this alternator for a 2005 GMC Envoy Denali. I am running 2 12″ subs with a capacitor to help with load. Stock alternator lights would still dim slightly. I bought this alternator in hopes that the lights wouldn’t dim, but they still did. What’s worse is the alternator crapped out after 2 and a half months. Stick with OEM not OEG.
Arturo –
Excelente
Muy bueno
Very bad quality –
very bad alternator in idle
Garbage I tried the alternator for one year and in parking idle when I switch on the AC and electric fan the vault drops to 12.9 and just accelerate rpm to or above 800 the alternator volt go up..So in idle very bad! I tried also to put short belt same problem!! Dont buy it waste money