Ok heres the deal i have a 1985 f350 460 v8 with a plow I have been having some problems with the battery dying so tonight I go to plow my first driveway and everytime i use the plow all the lites go off and the truck sputters, so i run out to walmart in the middle of the storm and get a 1000 cold crank amp battery, after 2 driveways the battery starts going dead again. I am assuming the problem is my alternator, what alternator can i get that will be able to keep up with the plow, lights, cb, radio, etc...



Matt

 

I would first check the voltage at the battery with the truck off, and then with the truck on. The voltage should be higher with the truck running, and this will tell you if the alternator is charging. We had a f250 company pickup with a 8' plow on it, no special battery or alternator, and we plowed with it constantly, all three shifts. It never died on us.

 

I seem to remember reading something in my manual about my Jeep fuse box having a fuse or something that would kick off when overloaded. Any possibilities like that? Maybe the lights and extras are too much for the circuit. I have always wired extra lights and high demand items directly to the battery with a relay and separate switch.

 

My truck was doing exactly what yours was doing the other day. Everything would go dead and truck would barely run. Turned out to be a fusible link on regulator harness. It did it about 3 times before going DOA. I would just go the a local parts store and have them hook up their charging tester to the truck. They do it for free out here.

 

The bigger the better! The alternator is doing all the supplying of energy for the acc's, the battery is a storge devise! When the Alternator is maxed out the battery will drain as needed. Some guys use two batterys to over come this, even both will drain if the alternator cant supply the acc's and charge the batterys.

Alternators will keep a battery charged up where its designed to! But thay are not actually Battery Chargers.

 

I don't think it is possible to buy an alternator big enough to handle the complete instant draw of a snowplow. Even if you did buy a 200 amp alternator, no one usually upgrades the wire from the alternator large enough to handle over 100 amps, and they also usually don't rev the engine high enough to get the full output. So the battery provides the cushion needed for short term spikes in high amp useage. If you average it out, it still will be getting charged over time, even though it is used to help the alt out.

I plowed with my truck a couple of weeks ago, and I found the idle speed to be the main culprit in poor electrical performance when I was plowing. I pulled the manual choke out slightly and it did very well. And it's completely stock with a regular battery and stock alternator(65 amps).

 

Yes the RPM's will make a difference. Some guys change pully size to help alittle on the RPM's, the best thing you can do is get a bigger one that has a modern regulator . Thay also cool better. Newer regulators not only know when to charge, but also how much and apply that gradually! This will provide SPIKE protection of electronic devices in your ride during heavy use.

my 2 cents

 

More rev's are the key to getting some amps out of your alt. No prob with a manual tranny, just tweak the screw on the idle cam on carb. With the manual you can idle anywhere you want, but with an auto tranny, you can only go so far. Pulling the manual choke works too, but isnt that harder on the gas gauge? I once drove about 60m with my manual choke pulled partway out, and used twice as much gas. I think the smaller alt pulley would be the way to go in the winter time. Where I live in the desert, I always idle at max for air conditioning. Some cars have a solenoid on carb to do that automatically when you turn air on.