129 k301 charging issues

Seanc · #1 07-07-2018, 07:20 PM

Hi all,
I’ve been battling an issue with my 129. The battery isn’t charging correctly. Put a volt meter on the batt and it’s full charge but when running the voltage jumps all over the place constantly. 3v, 13v 10v 2.5v 8v. There’s no rhyme or reason to it. It’s always been hard to start, so over the winter I replaced the condenser, points, ignition coil and battery. Then it still wouldn’t start right, so I took it to pasco and they rebuilt the starter/gen and replaced the voltage regulator. Got it home, ran fine for an hr and then the starter overheated and it wouldn’t start again. So took it back to pasco, they rebuilt the s/g again and replaced the solenoid. Warranty repair they said so they only charged me for the solenoid.
So today I’m at a tractor show and it ran fine all day until the last start and it left me stranded. I jumped it with my truck and it ran fine.

What the hell is wrong?! Why won’t it charge constantly with all these new parts? I’m over my head and tired of dumping money at Pasco.

Sean

Alvy · #2 07-07-2018, 07:46 PM

There is no common failure reason for those voltages you’re stating. You didn’t mention the battery. Does it pass a load test or have you load tested it? I’m assuming you’re readings are with the tractor running but where are you measuring the voltage? If a post is loose internally that’s about the only way to get those readings unless you’re taking them off the cables themselves and there’s a bad drop happening in between the cable lug and the post.....

R Bedell · #3 07-07-2018, 08:47 PM

The S/G and the V/R both have to be properly grounded and wired correctly.

olds45512 · #4 07-07-2018, 10:39 PM

Is the wiring harness still in good shape? Sounds like a bad ground or connection.

ol'George · #5 07-08-2018, 09:16 AM

As others have mentioned, as well as yourself, sounds like a intermittent connection.
Start checking and wiggling connections, not forgetting the ignition switch.

Seanc · #6 07-08-2018, 10:09 AM

Readings were taken at the battery posts while running. With tractor off battery is only reading 12.2v max after several attempts to start only 11v or so.

J-Mech · #7 07-08-2018, 11:35 AM

Quote:

Originally Posted by Seanc

Readings were taken at the battery posts while running. With tractor off battery is only reading 12.2v max after several attempts to start only 11v or so.

Sounds to me like you didn't have good connection with the multimeter you were using. That or the meter is junk. I'd check voltage again using a different meter.

When you say it wontstart, will it not crank? Or cranks, but won't start?
When you said "it" overheated after getting the S/G rebuilt, did you mean the engine, or the starter?
Your post is pretty vague....

jbrewer · #8 07-15-2018, 07:09 PM

How old is the battery?

12.2 is kind of low, but should start the engine. Dropping to 11 and change after a few attempts is not good (depending on the duration of the attempts).

Others have mentioned it, but check all the grounds. They go intermittent. Check the connection where the S/G bolts to the engine . They need to be cleaned enough to make good electrical connection too (current flows thru those joints). Clean the connections between the cables and the battery.

Sounds like you have two issues: Starting and charging.

The voltage at the battery posts themselves should be ~13- 14V when the engine is running.

The same voltage should appear at the output of the generator when the engine is running. Check it too... between gen output and gen ground RIGHT AT THE GENERATOR. It should be almost the same as that at the battery. If not, you've got some ohms to find :-)

John