ZT 2348XL blows charging fuse after a while

I just did voltage drop tests on the ground side, between battery NEG post and starter housing where it bolts to the block and also a test between battery and engine block.

In both cases the results were the same: intermittently high readings that corresponded to slow/failed starting.

When it spun easily the voltage drop was no more than 0.2v
When it wanted to "hesitate/stop" the voltage drop reading was at a solid 0.5v or so.


I could run the tests successfully and run them with failures with the only variable being when I turned the key.

At first I used only the battery and it went from 12.7v (same as last night's final reading) down to 12.3v, so at that point I added my battery charger set to "low" (13.9v showing at battery now).

Even with the boost from the charger, it would still frequently have higher resistance and fail to spin the starter easily.

I'm somewhat gratified that it's failing more now; that will make it easier to diagnose. I might temporarily replace the battery cabling, solenoid and starter cable and see if the intermittent nature of this disappears.

It's getting old running tests and having the same exact tests both pass and fail.

Installed a 6 yr old battery I have from another mower. It did slightly better than the 3 month old battery. Didn't fail to start but didn't have much grunt, either. This same battery works fine in my John Deere LX176 which has now decided to not activate its starter at all.

Took the normal battery back to the store. They tested it and replaced it. Their tester is the kind that "checks CCA" (by way of measuring internal resistance?) and it only had about 240 CCA (rated for 340 CCA). It was showing 12.65v.

The new one works better, but again anything less than about 12.9 or so volts is gonna still get that first grunt before the full spin. Overall this is the best yet but I still don't know if the starter has too much resistance.