# What size alternator do you use on plow truck



## kaufys (Dec 7, 2008)

What size alternator do you use on your trucks


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## drivewaydoctor (Nov 26, 2008)

I just had mine upgraded from a 90amp to a 130amp. That was the biggest they could fit in my engine compartment. Its a Dodge Ram 1500 5.2ltr engine.


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## Blazin (Mar 18, 2007)

Mine is being rebuilt as I type to 140 amp. Half the price of a rebuilt 95 amp from NAPA.


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## lawnproslawncar (Dec 9, 2007)

I got a 130 amp in my 2500 chev but when that goes I'll be putting the 200 amp in.


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## theplowmeister (Nov 14, 2006)

160 Amp in my jeep


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## carl b (Dec 28, 2006)

I've been thinking on this to much .. I post in the Ohio thread on this . theirs a guy not to far from me that can make my old one a 300 amp . I just got the phone number yesterday . Is their a such this as to much amps . I don't know what do you guys think ?


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## Runner (Jul 21, 2000)

It's not the size of the alternator - rating wise. you can spend all the money you want on the bigger alternators, and they still won't suit the whole need. It's not a matter of going from a 130 to a 200 amp (though this DOES help to a degree). This is the rating of amps it puts out at 2000 rpms. What you need is an alternator that puts out high amps at at LOW rpms. You need an alternator that puts out high at nearly an idle. One of the tricks to this is to change the gear ratio. This can be achieved by either a larger crank pulley, or more commonly a smaller alternator pulley, or a combination of both. We have ours built to put out higher amps at lower r's.


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## MAR4CARS (Oct 6, 2005)

I run powemaster alternators in my trucks 140 amp. they also sell a 200 amp but it wasn't in my price range nor really needed as i'm running 2 interstate 800 cca batteries.


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## Kenyou (Oct 13, 2007)

A friend of mine owns a alternator Shop and tried to build a bigger one for my truck as an experiment. He put in a lot more wire windings but there wasn't enough magnets to handle it. He said that you have to have a bigger (actual size) alternator to accommodate all that wire and have the magnets to be equal to the wire windings. He did put a smaller pulley on it but unless you have your foot in it, the amp gage drops big time when I raise the plow. So for now I am going to put the stock alternator back on and may look for a bigger one. Maybe he could put the smaller pulley on my stock alternator.


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## PLOWMAN45 (Jul 2, 2003)

i have dual optimas mine came with 145amp


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## MAR4CARS (Oct 6, 2005)

I should have added this in my previous post .. but you can also run dual alts. Custom install or theres some companies that make kits.


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## Runner (Jul 21, 2000)

That would certainly be a viable option, as well. I guess if you could fabricate a bracket (wouldn't be TOO hard) to hold another, you could directly power the second battery.


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## Krieger91 (Feb 7, 2008)

Runner;719320 said:


> It's not the size of the alternator - rating wise. you can spend all the money you want on the bigger alternators, and they still won't suit the whole need. It's not a matter of going from a 130 to a 200 amp (though this DOES help to a degree). This is the rating of amps it puts out at 2000 rpms. What you need is an alternator that puts out high amps at at LOW rpms. You need an alternator that puts out high at nearly an idle. One of the tricks to this is to change the gear ratio. This can be achieved by either a larger crank pulley, or more commonly a smaller alternator pulley, or a combination of both. We have ours built to put out higher amps at lower r's.


That makes sense. Can you buy smaller alternator pulleys from places like NAPA?

And, just another question, does it really matter on older, mechanical-driven pumps? My K20 has the old school pump mounted on the engine block and run off a C-belt, so extra power wouldn't be as big of a deal as it would with a new electric motor, right?

EDIT: One last question on this topic. On my '94 Blazer, would it be worth it to get a second battery when I get the plow on it? Or do you think I'd be better off getting the biggest battery possible and a low RPM, high amperage alternator?


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## zztarg (Dec 28, 2008)

145 Amps.

Most of the current will be drawn wen the pump motor starts from a dead stop - that peak current will be much, much larger than the (relatively) steady current that is drawn while the motor is running. Practically speaking, whatever size alternator you have, it probably won't be able to supply that peak current.

That's where the battery comes in. It stores energy and has a lot of peak power capability (hundreds of amps).

This is why the lights "flicker" (or dim) when the pump starts and then get a little brighter as it runs.


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## Bostonyj7 (Oct 30, 2008)

My 03 Silverado runs the factory 165 A alt. And my Wrangler runs a 98 Dodge ram 165A alt

Both work w/o problems at all

C-


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## doh (Sep 23, 2003)

Runner;719320 said:


> It's not the size of the alternator - rating wise. you can spend all the money you want on the bigger alternators, and they still won't suit the whole need. It's not a matter of going from a 130 to a 200 amp (though this DOES help to a degree). This is the rating of amps it puts out at 2000 rpms. What you need is an alternator that puts out high amps at at LOW rpms. You need an alternator that puts out high at nearly an idle. One of the tricks to this is to change the gear ratio. This can be achieved by either a larger crank pulley, or more commonly a smaller alternator pulley, or a combination of both. We have ours built to put out higher amps at lower r's.


Exactly why I run the Optional Delco 105 AMP @ low RPM Right out of GM's parts book. With around 900CCA battery, it has been all I have needed.


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## metallihockey88 (Dec 12, 2008)

doh;720021 said:


> Exactly why I run the Optional Delco 105 AMP @ low RPM Right out of GM's parts book. With around 900CCA battery, it has been all I have needed.


would you happen to have a part number for that alternator?...mine took a crap and went to buy a 140amp one and it has a different plug on it so it wouldnt work, was stuck buying another 105 POS one from the local parts store.


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## theplowmeister (Nov 14, 2006)

The problem with a smaller pulley on the alternator is you can over spin the alt and have it fail.


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## tuna (Nov 2, 2002)

Bostonyj7;719904 said:


> My 03 Silverado runs the factory 165 A alt. And my Wrangler runs a 98 Dodge ram 165A alt
> 
> Both work w/o problems at all
> 
> C-


Chu does the Dodge alt bolt right in place? I had a Powermaster in the YJ and it crapped out after about 3 months.


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## Bostonyj7 (Oct 30, 2008)

tuna;720271 said:


> Chu does the Dodge alt bolt right in place? I had a Powermaster in the YJ and it crapped out after about 3 months.


yes sir, it sure does. Found it on Pirate website. I can make sure of the year if you want


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## Stormrydervip (Oct 10, 2019)

I'm going to upgrade to a 250 amp, the biggest thing is to get one that runs at like 120 to 150 amps at idle which is when your lifting and lowering your plow. Hope this helps.


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## Mr.Markus (Jan 7, 2010)

Just buy a duramax and select the dual alternator option. 150a and 220a

Barely had my needle move plow, 2 yard electric salter, jagoff lights, electric compressor for the airbags, dump box with electric hoist...


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## leolkfrm (Mar 11, 2010)

op was 2009, might have a new truck by now


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## Mr.Markus (Jan 7, 2010)

My truck is a 2007 with 600,000 km


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## Hydromaster (Jun 11, 2018)

Most alternators will not put out their max until around 1200 to 2000 RPM.

A high capacity alternator is used to refill the pool faster.
If your plow has a heavy draw it could be time to get a bigger pool.

To get a bigger pool add a 2nd batt for a pair of batteries connected together.

& make sure the contacts are clean and tight.
Also a weak or old solenoid can also be a source of low current flow / high resistance.


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