put a plow on my 88 and know has mager power drop HELP!!&#33

[MidNight Towing of MN]

Put Awestern plow on my 1988 full size and had a m ajor power draw added second battery, and did a alternator upgrade to 150amp still has major power fad when using the plow anyone have an idea? :angry:

 

[BB33's]

Try upgrading the Guage of cable your using for the battery, 0 gauge would be best. Also you said you did an alternator swap, did you get a different pulley? an alternator won't put out 150 amps at idle, it needs to rev, a swap to a smaller pulley will make it spin faster and make more amps at idle.

 

[MidNight Towing of MN]

when I had the alternator built it was set up with a smaller pulley that ran 100+ amps at idle and 150+ at rev also using 0 gauge wires already

 

[BB33's]

Well then I'd look at your batteries, I know you said you'r running two but are they deep cycle? A standard battery isn't made to run under a large load. Hope that helps, I thought I nailed it with that last one.

 

[MidNight Towing of MN]

new batteries but there not deep cycle I will go buy a couple and give that a try Thanks!!!!!!!!!

 

[Seabronc]

You are probably wasting your money. The battery isn't intended to run the truck, just start it and supply momentary current shortages. The alternator is supposed supply all the load once the truck is running. No matter what speed you rotate the alternator it will only put out what is required to recharge the battery and supply the load. A 150 Amp alternator only puts out 150 Amps when the load requires that. If the load only requires 50 amps, then that is all it puts out. When they talk about the capability of an alternator they rate it in it's maximum ability at a given RPM, that doesn't mean that if they say it is capable of 100 Amps at 1500 RPM that it will always be putting out 100 amps at 1500 RPM. Also, those numbers are the Alternator RPM not engine RPM. Your stock pulley ratio is about 2.5 to 1, in other words the alternator is turning 2.5 times faster than the engine. The main reason for getting a smaller pulley would be that you primarily operate at low RPM and can't spin the alternator at a RPM to allow it to be capable of putting out it's full rated capacity at full load. If you over spin the alternator, you will seriously shorten it's useful life. Hope that little bit of alternator theory helps and doesn't confuse you.

The first thing I would do is remove all connections, clean them, check the condition of the ground cable from the battery to the frame and engine block. If they are not good, the alternator can't adjust for the heavy current demands and you will get a serious voltage drop in the electrical system. I would also move the voltage sense wire to the main distribution point. That is where you either find all the fusible links, ( usually the start solenoid), or a main lug on an under hood fuse box. It is the yellow with white stripe wire.

Good luck,

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