RZT 50 Battery Charging/Starting complications
 

Hello, all! I've been searching through the threads to find what I need, but nothing definitive. So...

I have a 2005 50" residential zero turn (17BA5A7P709) and I have a charging issue. (I think) I know in one thread, someone mentioned measuring the volts of the battery wide open. I also read to measure the volts going to and from the voltage regulator.

I understand starting at the battery and working down the electrical system to find the "weak link," the thing is, if the battery isn't charging, wouldn't that be a false starting point? I assume, to get accurate results, I should fully charge the battery first?

I assume my path of testing would go as follows:

1. Test Battery voltage
2. Test voltage going to Solenoid
3. Test voltage coming from Solenoid
4. Does #3 go from Solenoid to the Voltage Regulator?
5. (If not) Test Voltage to Voltage Regulator
6. Test voltage from V.R.
7. Should Test voltage at the starter be in there somewhere?

Long story, well, long, it doesn't start. I jump the battery and it starts right up. It's like it isn't charging so it has absolutely no cold cranking ability at all. I got the battery last year. It only had "good" starts half the summer. Bad thing is, I've replaced the Solenoid, VR, Alternator, wiring harness, and starter, all within the last year, so everything should be good, unless I just got a crap part.

Side note: I saw someone said they replaced their key switch and it fixed this problem. My daughter made fun of the face I was making when I read that because it makes no sense. But, I could be wrong, I guess.

I've tried to be as detailed as possible, but I'm sure I missed something.
Thanks in advance!

I think Step 1 should be a battery load test.
Reading a battery's voltage at rest means nothing.
If it craps out under load, you are chasing windmills looking at all the other places you list.

You can get a load tester at Harbor Freight for 18 bucks or take it to battery place or auto parts store and they will load test it for free.

Hmm. I guess I'm going to Harbor Freight later.

So finally got a chance to pick up a load tester. Battery is good; no damaged cells. Next test, I guess, would be charging it so it starts, then testing it running. The book says this tests the charging system? (Or is that only on cars?)

With the meter clamped to the battery, engine NOT running,
your meter needle should read around 12 to 12.5 volts.
Press and hold the load button for about 15 - 20 seconds.
For that time, a good battery will drop slightly but remain in the green area.
You should not need to charge the battery.
Leave the tester connected, start the engine, set throttle at least half way.
DO NOT press load button.
Read the meter, if you see at least 13 volts, your charging.

This does not really test the charging system, it only tells you what it is doing (or not).

Not running: in the green on the tester. (I think it was between target voltage.

I didn't test it pushing in the load button while not running. Will do that later.

I 100% need to charge the battery, or it won't start. As stated in my initial post, the battery doesn't charge while I mow.