318 electrical issue

[cef2lion]

My borthers 318 has an electrical issue. There was some smoke coming from battery area and it quit. A couple hot wires. We tested battery and it only showed 6V. Battery was old. We replaced battery and fixed up the wires. All seem ok for two days. He just called and said it was smoking again around battery and it quit. There seems to be a big short somewhere. They were driving it but not using the PTO for mowing.

Last year we pulled the engine to fix the starter. We used care in installing the engine so the positive battery cable didn't touch frame. Near as we can tell it isn't loose or touching. Can't see well enough as it travels to battery.

What other areas could be causing this issue? I see a black box behind battery. Do these have alternator or generator. What about a regulator.

It does start. He says it seems to be ok till it gets hot. I said not to use it till we solve this. I did ask him to start it and get a voltage reading off the battery.

Craig

 

[cef2lion]

Still having this issue. Replaced the battery. Looked for bare wires. It runs good for awhile. I test DC output at regulator. It is just over 13V. AC output from stator is about 15V at idle up into the 20s as RPMs increase. Ran it for 20 minutes and checked voltage and wires for heat. All was fine. Drove it around a bit more and tested and looked. All ok. Mother-in-law used it yesterday. After running it a bit without PTO it started to smoke in battery area. She shut it off. Battery cable terminal on the NEG side was melted off.

I pulled the IGN switch connector and it looked ok. Not sure about he switch itself. Fuses have never blown. Not sure what to check next.

Craig

 

[cef2lion]

The next plan is to pull inspect and replace the NEG and POS battery cables. The thought being there has to be a major short to ground to cause the NEG battery battery terminal to melt.

THe POS battery cable takes a route down under along the frame to the starter. It has the Deere starter enhancement kit on it as well. It provides more power to the starter solenoid then the way it was from the factory. It was a relay placed down by the starter that eliminated power loss on the long run down from the the IGN switch.

I do have a diagram for the wiring harness off the JD parts site. I have a good idea on the wiring for the 318 now.

I pulled the starter and had it rebuilt last summer. I was very careful installing the engine and routing the POS battery cable as I saw a possible issue with it and the frame. It ran good up to fall and was put away. Very hard to get at the battery cable were it attaches to the starter. When it did lose power it corrected itself once when they got back on it. I think it shifted the bare wire where ever it is. My guess its the POS battery cable when you lose sight with it under the frame.

Craig

 

[cef2lion]

Issue resolved. Battery cable at starter worked itself straight down. When axle pivoted it came up and contacted cable. Adjusted cable an tightened terminal nut back down.