after market alternator?

I own a 1981 B7100 that I mainly use to move snow. I have a 3 point hitch mounted snow blower which requires me to back up all the time to move my snow.

Since it's dark a lot of the time here in winter I added 2 18w LED offroad lights and 1 amber strobe light (some of time I'm in a road) on a pole and find my battery going dead on me. My tractor didn't have much in the way of lights and these help, but I now need a stronger alternator.

Has anyone added an aftermarket alternator to their tractor? I have found a 35amp mini-alternator that should cover the lights and then some. I am wanting to a clean job of it and try to keep it under the hood. So I'm asking if anyone has done this and can provide pointers...

Future plans include a full set of gauges/tach and a fuel gauge.

Thanks in Advance!

85Hokie said:

Dan,

welcome to the forum !

mmmmmm....something does not sound right here......your dyno, (not a true alternator) MUST not be "charging" the battery, despite it only putting out about 10 amps or so at full throttle it should be plenty to cover the load of those lights.

Have you checked voltage at battery while off? AND while running?
good battery should be 12.6+ vdc and a charging voltage for that machine while running at 2400 rpm or more should be 14.4 or better.

report back what you find out

Click to expand...

Okay, I ran some tests as you mentioned and here is what I found.

Engine off prior to start my new battery read 12.79 volts.
Engine running at idle with lights OFF it read 13.70 volts.
Engine running fast with the lights OFF ---> 14.58 volts.
Engine running fast with all lights ON ---> 13.90 volts.
Engine running at idle with lights ON ---> 13.20 volts and dropping.

My Kubota has a standard transmission and I can't run the engine fast all the time when I need to use my loader, just not practical. Now I ran it at full load/idle long enough to see the voltage falling not to see where it was going to level out it, I'd suspect quite low.

My aftermarket LED lights are popular on Amazon and I suspecct they draw more than the 18 watts they are advertised at. But they do light up the area quite well, better than the little taillight the tractor comes with.

My only complaint is where and how I mounted them. The loader controls have a flat area on top and I constructed a 1" box tubing with a flat plate on the bottom and mounted it the the top of the controls. The LED lights are mounted above eye level, but the chute on the snow blower/snow blocks the light when angled to the right side of the tractor and the loader on the front blocks the light when the loader is raised. But so is my vision - I guess that's a toss-up.

seanbarr said:

Found it...

B7100 alternator upgrade

Sent from my iPhone using Tapatalk

Click to expand...

Thanks for the info!

A question; did you leaving the original charging system intact or disconnect it?

I think I'll try to replace the tensioning adjuster with the new alternator and modify the hood of the tractor with a bump/shroud if the alternator gets in the way.

As I mentioned in my first post I plan on installing a full gauge package. I'll make a bump or shroud for the top of the hood towards the front and put the gauges under it. I will add a fuel gauge sender to the diesel tank using a marine type of sender. I'll post pictures of both projects when I figure out how to post a picture.