John Deere 318 Not Charging!

[Scotty370]

Guys, don't kill yourselves on this one, I've got the huge service manual, that I've yet to deleve into. But just wondering if anyone knows of a 'trouble-spot' that I should be looking at first! Thanks in advance! ~Scotty

 

[Treemonkey1000]

Loose fan belt, corroded wires at alternator or generator, blown fuse, wire broken in the system, bad cell in the battery...
That's a start (pun intended)

 

[dcyrilc]

Disconnect the battery and try charging it with an plug in battery charger. If it takes a charge, you've eliminated the battery from the possibilities. If not, then you've identified the battery as the problem.

 

[Wayne_H]

I've replaced the rectifier/regulator on my 318 at least twice in the past 20+ years. Suggest looking at that.

Wayne

 

[ol'George]

If it is not charging and the obvious connections are tight/clean then it is usually the rect/reg.
I did one time, on a kohler, have a plug slip off the reg/rect. and I found this out after I bought a new one.
no matter, a few years later I needed it as the old one went bad, and they do go bad.
Kind of like a headlight, good service but in time,they burn out.

 

[Scotty370]

Thanks Guys! I may have a problem with the ignition switch, as it sometimes has to be 'wiggled', before starting, but I replaced it once! I didn't think that would have an effect on the charging circuit once it was running! The battery is good, and up to charge,(12.6v). Think I'll go after the Regulator, as it's never been replaced. Poor thing sits outside 24/7/365! TIA ~Scotty

 

[dcyrilc]

Thanks Guys! I may have a problem with the ignition switch, as it sometimes has to be 'wiggled', before starting, but I replaced it once! I didn't think that would have an effect on the charging circuit once it was running! The battery is good, and up to charge,(12.6v). Think I'll go after the Regulator, as it's never been replaced. Poor thing sits outside 24/7/365! TIA ~Scotty

The next thing I would check, is the voltage at the output of the regulator while it is running. If it is the same as the battery, the regulator is bad. If it is higher as it should be, the issue is in the wiring, connections, or battery cables.

 

[eepete]

An up to charge battery should be over 13 volts. Above 13.8 volts, you start to get electrolysis. Above 14.5, it really starts to boil off the water. While that _should_ be independent from the regulator, the regulator will be running wide open trying to charge that battery so if it's marginal the regulator might be unhappy.

Just more data for you, dcyrilc debug path is still the one to follow. BTW, my 318 is 19 years old and on it's original regulator.

Pete

 

[ol'George]

If you are wiggling the switch, bet ya a dollar to a donut,you have a connection problem not a regulator problem.
When you pull off the connector@ the back to the switch, remove the wires from the connector and check to see if they are tight on the switch spades.
Do this one @ a time so as to make it non confusing.
I have seen where they have been arcing,because of poor connection causing the plastic connector to melt.
You might have to change 1 or 2 connectors, if they are really bad and have lost their springiness. ( avail @ auto stores old style G.M.)

also check the switch spades or treiminals for corrosion/rust if it sets outside.

 

[Scotty370]

Just thought I'd give an update, and thanks for your input! I replaced the switch. I looked up the part numbers on JD, then Google for 'crosses'! (Yeah, I'm 'thrifty') Switch from JD- $19-, switch from local small engine guy- $12.99. That solved the 'wiggle-thing'! Pulled the two outside regulator leads and have 32VAC at medium idle. They call for 26-52VAC at high idle, so I'm in the range! re-plugged them, and pulled the center lead on the Reg, and got no DC output! Looks like the regulator!! Called JD for Reg price, $81-!!! Checked Google for a 'cross' that led me to EBay. and ordered an exact replacement for $31-!! More to follow! Thanks Again! ~Scotty