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Alternator Questions?

Discussion in 'Commercial Snow Removal' started by Repo, Dec 13, 2004.

  1. Repo

    Repo Junior Member
    from Pa
    Messages: 3

    Hello All,

    Got a question on alternator size (ie. Amperage needed) and how to determine how many amps current alternator is producing?

    My equipment is as follows: 1990 Chevy 3500 4x4 454 cu. in. auto trans.
    New Boss 9'2" Poly V-plow
    Snow-EX 1075 Tailgate Spreader
    10' x 7' Crysteel Dump Bed

    I would like to find out if I need a bigger Alternator? I think the one on it is a 60 amp version? Could be wrong. Is there a way to to use a Multimeter to find out exactly what the alternator is producing? I know how to check the voltage at the battery and it's now at 14.10 volts. I've been told to put a 200 amp on it and the local auto parts store told me I go up to only 105 amps? I have a Interstate battery that is almost two years old and I'm having alittle trouble with it starting if I let it sit for a couple of days. I'm also leaning towards the purchase of a Yellow Top OPTIMA battery for this vehicle and maybe going dual battery set-up. Thanks in advance for any and all help.

    Still no snow here?
  2. TLS

    TLS PlowSite.com Addict
    Messages: 1,425

    I have the same truck as you, except mine is SRW.

    They came from the factory with an 85amp.

    But I have been through about 3 on mine, with the latest being a 145amp generator shop rebuild. So, unless your the original owner, it's most likely been rebuilt or replaced. And its doubtfull it was with another 85amp'er.
  3. Tarkus

    Tarkus PlowSite.com Addict
    Messages: 1,113

    My guess is that it has a 105 amp unit on it as those where real common. I would not upgrade to a 145amp unit without upgrading main buss wiring or you could have some serious issues arise. Dual batteries would be an very viable upgrade for a lot of reasons and the most important being more reserve capacity and better battery life under constant charge/discharge cycles because the load is split between them and the each carry have the current and there is less gassing of battery due to lower peak demands and better battery effiecency as well. Two mid grade batteries in parallel will easily out perform and out last by a good bit any single battery you can by at any cost that will fit in your stock battery tray.
  4. Mark Witcher

    Mark Witcher Senior Member
    Messages: 605

    You can take your truck to an auto electric/battery shop and they can test the alternator on the truck and tell you exactly what it is putting out. I have been plowing for 10 years on large parking lots and none of my rigs have more than 100 amp alt. and except for the one diesel truck, only one has dual batteries. I have never had a lack of power to run everything.All my rigs are running a 95 to 102 amp alt. These were tested,and are their true output. You never know about those over the counter ones from the parts stores.
    Last edited: Dec 13, 2004
  5. Tarkus

    Tarkus PlowSite.com Addict
    Messages: 1,113

    I have never gotten any single battery in a gas plow truck to be much good past 2 or 3 years but dual batteries go 5 or 6 years for me with no problems.
  6. LINY Rob

    LINY Rob Senior Member
    Messages: 478

    my jeep's single battery is 5 years old
  7. ace911emt

    ace911emt Member
    Messages: 83

    I f you want overkill up grade to a twin alternator set up. both our 4x4 ambulances have them (Factory Chevy’s) The addition of a second single wire alternator could be an easy fix, and not to hard to fabricate, but the duel battery set up is a must.
  8. Bldrs83

    Bldrs83 Member
    Messages: 96

    Is it true that a higher output alternator actually puts out lower amperage at idle than a "stock" alternator?
  9. LINY Rob

    LINY Rob Senior Member
    Messages: 478

    alot of people look at the rating and do not look at the specs to see what engine RPM you need, it may be 140amps, but that might be at 2000 rpm, I dont see 2000rpm driving around my parking lots thats for sure
  10. TLS

    TLS PlowSite.com Addict
    Messages: 1,425

    You don't? I do.


    Plus the trip from job to job is when it can catch back up if it's low.
  11. LINY Rob

    LINY Rob Senior Member
    Messages: 478

    the trip job to job isnt the problem, its the low rpm driving and the constant operation of the plow thats the draw on the system

    It will be interesting to see if my new truck has a problem plowing compared to my old beater that never had any.
  12. 85F150

    85F150 Senior Member
    Messages: 340

    to do a proper dual alt setup is going to cost 300 -400 bucks for a controller. if nt done this way the alts wil be fighting over how much to charge or even overcharge the battery. THe purpose of dual alts on commercial vehicles is
    1. more reliabilty- dual alts split load in half with proer controller thus less wear on the alt
    2. redundancy - backup alt if one fails and no time to fix it.
  13. lawnmedic

    lawnmedic Senior Member
    Messages: 703

    Just replaced the factory Alt. on my 89. It survived 5 seasons of plowing. It was a 85 amp, and I replaced it with a 105 amp. The battery was replaced last spring after 4+ years of service. I have never had a low voltage problem on this truck while plowing, and this trucks route has over 6 hours of plowing all within a half mile total....
  14. Tarkus

    Tarkus PlowSite.com Addict
    Messages: 1,113

    No need to do this unless you want to be able to isolate batteries to use them seperately. There will be no "fighting" for the charge. They will work just fine in parallel and use at least 4 ga or heavier for the straping wire and ground each battery seperatly to the engine block too.