battery problems onL2550

[skyhook]

In my experience,
these L2550's are equipped with poor alternators and regulators,
not enough amperage and regulated voltage.
I installed an older type (gm) alternator, it bolts right up but you may need to shorten the belt.
These gm alts come with a built in regulator, so you can eliminate that crapy regulator
that came with your tractor.
Wiring the gm alt in is simple. Outcome, you'll have a happier, better charged battery.

 

[geneo]

That sounds like a good plan that i would consider doing if i have to replace the alt. How did you wire the gm alt. to the kubota wiring . Could you post a diagram??? My kubota alt. has a 3 wire plug and the gm only has a 2 wire plug.

 

[skyhook]

That sounds like a good plan that i would consider doing if i have to replace the alt. How did you wire the gm alt. to the kubota wiring . Could you post a diagram??? My kubota alt. has a 3 wire plug and the gm only has a 2 wire plug.

You would remove your alt and "not use" the voltage regulator at all.
You could leave it in place if you wish.

Here's the set-up for the gm alt...

The #2 wire that goes to the 12 volt battery can be connected directly to the ( BATT) terminal on the alt.
#1 wire goes to any feed wire that gets juice when the key is "on", ( this excites the alt and makes it start charging). There must be no power to this wire when the key switch is "off'.

 

[geneo]

Checked alt. with lights on .Voltage is 12.8 running , 12.5 with lights on and tractor at 1500 rpm's. Alt. is not hot or even warm.

 

[skyhook]

Ya, it doesn't seem to be charging the way it should,
it is charging, but not the way you would like it.
You should be up in the 13.5 volt area at that rpm.
I know some people who upgrade their trucks ( 7.3 diesel engines) with the 3g alt system.
This alt is much better and really puts out the amps, but wouldn't fit in your tractor.
I'm sure if you would rev up your tractor to about 2,500 rpm's, the voltage would or should rise
to the 13 volt mark. Still not adequate enough in my books, especially if your running lights etc.

 

[SPYDERLK]

Sorry, I cant reply with Quote. ... You alternator is not working. We need to determine if it is being "asked" to work. To do this, measure the voltage from ground to the white/striped wires on the 3 terminal connector on the back of the alt. The lower one [wht/grn] should have 8V or more. The upper [wht/blk] about 5V. If no voltage the alt is not being asked for current. This V should be present when ignition is on ... running or not.
larry

 

[geneo]

Did check on alt plug. With engine running, upper wire has 4.3 volts and bottom wire has 8.7. With engine off , key on , top wire 0 , bottom wire 11.3 . With tractor running @ 1500 rpms ,i'm showing 12.6 volts. The battery seems to be staying up and tractor is starting , but i'm wondering if its because i've been starting it so often to check voltages.

 

[SPYDERLK]

Your batt is slowly going down with starts. Discharge while running is very minimal unless lights on.

With those voltage readings the alt should put out some power. ... Look down by your dipstick - near the starter. There should be 2 wires going into a connector and a single wire looping back on the other side. This loop is a fusible link and may be bad. It seems to me that if that link is bad and the engine OFF you would see no voltage at the red wire stud connection on the alt. I really dont want to unplug that functioning 30 yr old fusible link connection to check this on mine. If you have sharp probes you should be able to stab them in on the side of the connector having the 2 wires. If the fusible loop is intact the V between those 2 wires should be very small with the engine running or not. If its 12V, the link is blown or the connector fouled. Correcting that will be the answer I think.
larry

 

[geneo]

found the wires but someone before me has replaced the fusible link with a in line fuse..20 amp...It's not blown . I have 12 volts at the red wire on the alt. I mowed for an hour today and the voltage at battery afterward was 12.6 volts without the engine running. Tractor started fine this morning when I started mowing...

 

[SPYDERLK]

OK. The problem is that I think your alt is working at a very low level. The question is whether thats all it can do, or that the Vreg is governing it to that anemic level. By experience [and off the top of my head] I believe the numbers you gave for the alt connector plug correspond to around 12.8V out of the alt. Im concerned that this is so near the batt rest voltage that its difficult to tell if its charging at all. I would probably just run a wire from batt + to the lower plug connection. Thats me ... and unfortunately Im not sure whether that would be bad for the Vreg. What would surely be safe is to unplug that connector to take the Vreg out of circuit, and put 12V across the outer [blk] terminal and the lower [wht/grn] terminal on the alternator. This would ask for full charge from the alt. If the alt is working the batt voltage will start to rise and alt will warm. ... That will say theres something wrong in the Vreg part of the system. Probably the Vreg :confused3:
larry