Alternator / generator not charging

Dan_R_42

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Equipment
B7100-D, w/ Sims Cab, B219 FEL, ARPS 70 Backhoe, Oversized R4 Tires, LX2610 Cab
Dec 1, 2010
447
3
18
Taunton, MA
I have two wrenches bent just for this operation as I have removed these covers 8-10 times when the head is on. ````` Unless you have very small fingers getting that nut restarted is worse than removing it.

I will 3rd that request. Would definitely want to see how you shaped the two wrenches to get them to fit. :D
 

kubotasam

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B2410, B7100dt, B7500,Woods BH750,Landpride 2660RFM, Tiller, B2781 Snowblower
Apr 26, 2010
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125
63
Alfred Maine
Well I guess this old brain is starting to crumble. I just went out and put a meter on one of my B7100's. I was wrong with what I said before. I had 16 VAC at idle and 40 + VAC at full throttle. Sorry for the misinformation in the previous post.
 

Lil Foot

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1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
May 19, 2011
7,259
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Peoria, AZ
I just went out and put a meter on one of my B7100's. I was wrong with what I said before. I had 16 VAC at idle and 40 + VAC at full throttle. Sorry for the misinformation in the previous post.
Even better to know, thanks!
 

JoBo

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Equipment
B5100, D905 powered generator
Mar 15, 2014
23
1
0
Columbus, Ohio
I've had my water jacket/dynamo on and off twice in the last week or so and used a "Gear Wrench" to reach that almost impossible nut:eek:
Every few clicks of the wrench I rotated the gear head 2 clicks and gained more travel.
To make getting the nuts back on easier you want to have the threads really clean. I used small long nosed pliers to put the nut into position then held it in position with a small long screw driver. Next using another thin screw driver turn the nut until it starts threading on.
This is harder to put into words than actually do:)
The water jacket/dynamo has to come off to reach the center hidden bolt when removing the gear case cover:(
 

Zogman

New member

Equipment
B7100
Mar 16, 2014
26
0
0
Lake Elsinore, CA
I finally had a chance to check the voltage output of the dynamo. Max output at full throttle is 28 VAC. On the output side of the regulator not plugged into the load, the output of the regulator is 23 VDC. Once I plug the lead into the harness the voltage of that lead drops to 11.8 VDC which is what the battery is reading.

I read elsewhere that the regulator may only put out if the battery drops below a certain level. Not sure if there is any credence to that.
 

chris attwell

New member

Equipment
B7100
May 26, 2014
2
0
0
australia
the voltage a/c across the two wires is the most important thing to measure,I got only 3.5volts so ?? the resistance from each wire to earth, was 3.5 and 10 ohms. wolfman is correct you can bend a cheap 10mm ring spanner, and remove that hidden nut..getting it back on ?the alternator was Full of 26 years dirt I have cleaned it .BUT,need to know what the voltage ,ond ohmage should be before I try that nut!! chris.
 

cerlawson

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Equipment
rotiller, box scraper,etc.
Feb 24, 2011
1,067
3
0
PORTAGE, WI
Not seeing the schematic, I have a basic quesiton. All the alternators i have run across have the diodes in the Alternator casing and what comes out is DC. In the case here, where are the diodes to change to 'AC to DC? There might be 4 of the in what is called a "bridge circuit". Two diodes may be in a singe case as part of this. One video on this.

https://www.youtube.com/watch?v=RCKgQ4somTk
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
28,286
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Sandpoint, ID
All the alternators i have run across have the diodes in the Alternator casing and what comes out is DC.
You would be exactly right if it was an alternator.
The problem is it's actually a Dynamo, and dynamo's are different from both alternators and generators.
The output is a weak AC output.
 

JRHill

Member

Equipment
Orange: B7100 Std and Woodmizer; Green/yellow JD Buck, Gator and 410j.
Apr 26, 2016
59
11
8
Wahkiacus, Washington
Hi Folks. I need to revisit this old subject. First, my charging system has not been working for a few years. When parked, I plug it in to a maintainer so it will start the next time. After starting there is really nothing drawing anyway so not a problem. The real charging problem is probably the wiring behind the dash. It was cobbled and recobbled long before I bought it 30 years ago. The charging system worked long ago but has aged like me to be (occasionally?) non functional.

Before I get into the generator/regulator I need to have a wiring diagram so I can replace the cobbles with fresh wire and connectors. I also need to replace the starter just to get it running again and I found one on Amazon for $65. Cool. The starter has been sluggish for years as well and the 'ol critter needs all the spin it can get in cooler weather.

Can any one help me with a diagram of a late '70s B7100 manual?
 

RCW

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BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Apr 28, 2013
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Chenango County, NY
Can any one help me with a diagram of a late '70s B7100 manual?
Try these two places for a workshop manual (WSM):

http://kubotabooks.com/


I see kubotabooks has a 24+MB file labelled Operators, but due to file size betting it's a WSM.

Also, sometimes part diagrams help:

 

JRHill

Member

Equipment
Orange: B7100 Std and Woodmizer; Green/yellow JD Buck, Gator and 410j.
Apr 26, 2016
59
11
8
Wahkiacus, Washington
Thanks RCW. I checked all three and I couldn't get a diagram from any of these sites. I can "sound it out," it just takes a bunch of extra time.
 

wgator

Active member

Equipment
L4701HST, FEL and other stuff.
Jul 28, 2018
482
147
43
NC
It's near the back of the operators manual. CLICK HERE to see it in the online/downloadable operators manual.
 
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RCW

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BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Apr 28, 2013
8,282
3,866
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Chenango County, NY
It's near the back of the operators manual. CLICK HERE to see it in the online/downloadable operators manual.
Thanks, 'gator. Thought there was a diagram in those somewhere, but honestly didn't look myself.
 

GreensvilleJay

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BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
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re: where are the diodes to change to 'AC to DC?
they're in the 'regulator' module. It's really a recifier/regulator module as it has diodes to convert Ac to Dc then SCR/zener or similar to regulate to 13.2 volts+-. Same configuration as 99.44% of all 'small engines' used on riders, like B&S engines.
 

Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
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Thanks RCW. I checked all three and I couldn't get a diagram from any of these sites. I can "sound it out," it just takes a bunch of extra time.
I have attached the wiring diagram and other relevant info.

Dave
 

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GeoHorn

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Just to keep things stirred-up..... Actually a generator makes DC current by use of a commutator which reverses the armature-coils polarity as the coils pass by the field shoes.

An “alternator” is actually shortened terminology for “Alternating-Current-Generator” ....a portmanteau... shortened to “Alterna-tor” which generates AC current because it does not have a “commutator” but instead has slip-rings which cannot reverse the sine-wave into DC currnt except via a rectifier made up of diodes.

A “dynamo” is a British term... a machine for converting mechanical energy into electrical energy; a generator (with a commutator so as to produce DC current).

There! Hope that clarifies things. :ROFLMAO:
 
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JRHill

Member

Equipment
Orange: B7100 Std and Woodmizer; Green/yellow JD Buck, Gator and 410j.
Apr 26, 2016
59
11
8
Wahkiacus, Washington
I'm getting some expert help here. It's not rodents:
I have attached the wiring diagram and other relevant info.

Dave
Thank you so very much, Dave. This is exactly what I needed. I'm going to rewire this critter. I'm trying to find bulk spools of different jacket colors and I keep getting copper clad aluminum spools. Are there any hints for 16ga copper spools of and assortment of jacket colors? I keep striking out.
 

Dave_eng

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Oct 6, 2012
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I'm getting some expert help here. It's not rodents:


Thank you so very much, Dave. This is exactly what I needed. I'm going to rewire this critter. I'm trying to find bulk spools of different jacket colors and I keep getting copper clad aluminum spools. Are there any hints for 16ga copper spools of and assortment of jacket colors? I keep striking out.
My experience in keeping old vehicles going is that spending a bit more on the basic wire provides much greater long term reliability.

I will use one example..... the flat wiring harness used for trailer lights on trailers sized to be pulled by cars and pickups.

I make every connection using soldered joints. A few years later a lamp gets broken and I need to solder in a new fixture.

Stripping back the flat harness plastic insulation reveals heavily oxidized copper wire. To get solder to stick to this wire requires lots of sanding to get the strands in a condition to be soldered.

Oxygen from the air we breather is diffusing through the plastic insulation oxidizing the copper wire.

Wire made for marine uses is tinned. The copper strands are coated with a solder like material preventing the copper from oxidizing.


Why Use Tinned Copper Wire?
Written June 2019 | Tony Holderby, Regional Sales Manager at Service Wire Company
The sole purpose of electrical wire and cable is to conduct an electric current from one point to another, but if the cable starts to corrode, it can quickly become damaged and result in loss of performance. While bare copper is fairly resistant to corrosion, tinned copper conductors prevent accelerated corrosion against wet and contaminated environments.
Protection Against Copper Corrosion
Tinned copper is primarily used for protection against oxidation and corrosion. In climates where copper has long-term exposure to water, the oxygen will combine with the metal and form copper oxide, weakening the bonds of the metal. It is worse if the wire is in contact with salt water. As more of this oxide forms, it weakens the integrity of the copper making it brittle and crumbly, a process known as corrosion. Corrosive copper wire is less efficient at moving electricity and can cause safety hazards.
By coating bare copper with a thin layer of tin, it can strengthen the copper’s natural properties, giving it extra protection against water, weather, and exposure to other corrosive elements while maintaining the same conductivity. Tinned copper wire is also easier to solder to connections as tin is a key element in soldering, ensuring all parts of the wire are protected against corrosion.
Tinned Copper Applications
Tinned copper wire is particularly useful in wastewater treatment facilities, underground subway systems, and projects exposed to excess oil, gas, or water. Tinned bare copper is frequently used in utility projects in the Northeast and environments exposed to excess sodium-chloride salts (seawater).
When considering bare or tinned copper, the environment should be a determining factor in the wire selection process. Tinned copper can extend the life of your cable, but it isn’t easily retrofitted in all projects. Thinking ahead and planning for potentially corrosive environments can prevent total replacement jobs in the future.

Amazon is a reliable source for high quality marine grade wire.

Finding wires with the jackets in the many colors and stripped patterns you would like will not be possible when buying in the quantities you need.

Amazon

Dave
 

JRHill

Member

Equipment
Orange: B7100 Std and Woodmizer; Green/yellow JD Buck, Gator and 410j.
Apr 26, 2016
59
11
8
Wahkiacus, Washington
Yup. I've been here before. Colored electrical tape tied with UV wire ties. Even then they don't last.

I've always lightly soldered crimp connectors. Even though the flux is hard to fully remove its better than a plain 'ol crimped joint that gets wet/moist, etc. The best is the marine shrink tube with the glue jacket. Even then, finding good quality stuff is a challenge.
 

GeoHorn

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Soldered connections in high-vibration environments can lead to broken wires because the solder stiffens at the end of the soldered joint..... which is where the wire will break. In aircraft (which also use tinned, stranded, wire... crimped connections are preferred, and mandated in most installations. (High-grade tinned, crimp-connectors and terminals, etc. are used rather than the typical automotive types made of rolled sheet-metal which do not completely surround the wire.)
Aviation-grade wiring also does not use PVC or vinyl insulation...instead using a Mil-Spec polymer termed “Tefzel” which does not attract rodents and does not emit cyanide gas when burned.
 
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