149 Possible Short in wiring?

[Mr Bob]

Asking for help once again. The Cub 149 that I have been refurbishing for over 4 years has developed a problem. Sat in garage for about a month and a half. It started right up and moved it out in front of garage. Let it run for a few minutes and it had a miss just above idle. I adjusted on the carb. and helped it a little. Shut it off and restarted. Started right up. Shut it back off. I do not have the fender mounted and was sitting on the rear tire. Saw a couple sparks on positive battery terminal. Moved pos. cable and it was not tight . Went to tighten it up and sparks flew when wrench hit nut. I then disconnected neg. cable and removed the pos. cable. Battery tested at 13.26 volts. I cleaned all cable ends and terminals. Could not hook up cables as bolt got red hot. I must have a short, but I looked at all wires and found none burned. Any Ideas? All help appreciated. Also, which cable should be hooked up first? Have a great day.
Bob

[MBY852]

Originally Posted by Mr Bob

Asking for help once again. The Cub 149 that I have been refurbishing for over 4 years has developed a problem. Sat in garage for about a month and a half. It started right up and moved it out in front of garage. Let it run for a few minutes and it had a miss just above idle. I adjusted on the carb. and helped it a little. Shut it off and restarted. Started right up. Shut it back off. I do not have the fender mounted and was sitting on the rear tire. Saw a couple sparks on positive battery terminal. Moved pos. cable and it was not tight . Went to tighten it up and sparks flew when wrench hit nut. I then disconnected neg. cable and removed the pos. cable. Battery tested at 13.26 volts. I cleaned all cable ends and terminals. Could not hook up cables as bolt got red hot. I must have a short, but I looked at all wires and found none burned. Any Ideas? All help appreciated. Also, which cable should be hooked up first? Have a great day.
Bob

The reason to connect the positive cable first (in a negatively-earthed car) is that while tightening the positive connector with a spanner (wrench), if you were to touch the body of the car or tractor with the spanner at the same time, nothing would happen and it would be OK.

However if the negative was already connected to the battery and you shorted the positive to the body with the spanner, there would now be a short circuit with a big spark and a possible fire. For the same reason you would disconnect the negative connector first too.

[Mr Bob]

Thank you MBY852. I'm sure that at some point in time I knew the correct way. My memory is failing so thank you for telling me the correct way. I am going down now and try to connect them. Have a great day.
Bob

[cooperino]

Bob.

When it comes to electrical the rule is "divide and conquer" For this to be happening it must be something that pulls a good amount of current like the starter. Look at all the wires between battery and starter. Also look at all wires going to VR. What I find to be peculiar is that your battery seems to be fully charged. You said the positive wire was on but loose. A short like that would have normally killed the battery.

Edit.
You said you have the fenders off. You had the battery out?? Is it at all possible that your hooking the battery up backwards? Just saying that would cause a short like your talking about.

[MBY852]

Originally Posted by Mr Bob

Thank you MBY852. I'm sure that at some point in time I knew the correct way. My memory is failing so thank you for telling me the correct way. I am going down now and try to connect them. Have a great day.
Bob

Your welcome Bob! I know what your talking about with the memory. Wait, what were we talking about?

[ironman]

Mr. Bob, you are working on a 149 and you say you have the fender pan off.
On 149's (mine at least) the battery and the voltage regulator are positioned in the fender pan, under the seat. The grounds for the negative battery pole and ground for the voltage regulator are connections to the fender pan (again mine at least).
That would mean you must have some kind of temporary wiring in place to make your connections. Maybe you got something there misconstrued.

[Mr Bob]

Thanks for all the reply's. Wen't to the garage and did more unprofessional checking. Took pos. wire loose at the amp meter. Touched neg cable to different battery and no sparks. Hooked wire back to amp meter. Took 3 wires off voltage regulator. Touched neg. cable and again no sparks. Re-hooked all 3 wires. Checked yellow wire on starter and it was a little loose. Tightened it. Checked pos. cable on starter and it was very loose. I knew the threads were stripped part way down, but now the nut will not tighten at all. Everything was hooked back up so I turned key to start tractor. Started right up. Ran for maybe 2 minutes and ground cable at battery started getting hot. Shut tractor off and took ground cable off. It was still getting hotter even after tractor was shut off. I mean it was red hot by now. Could the pos. cable being loose at starter cause the problem? Tractor ran well about a month and a half ago. I just don't know how it could develop a short just sitting in garage. Pictures attached. Thanks for your help and have a great day.
Bob

[R Bedell]

ground cable at battery started getting hot. Shut tractor off and took ground cable off. It was still getting hotter even after tractor was shut off. I mean it was red hot by now.

Simple solution. Go to the Tech Library and look on Page #5 for the Wiring Diagrams. Download the 1x8/9 Wiring Diagram and check to make sure that all wires emulate the diagram.

[MBY852]

If your wiring looks good and all snugged up maybe the battery could be shorting internally and may need replaced. Some of the auto parts stores offer free battery testing like Nappa, Advanced auto,etc and can diagnose whether the battery is faulty. Process of elimination.

[darkminion_17]

Originally Posted by R Bedell

Simple solution. Go to the Tech Library and look on Page #5 for the Wiring Diagrams. Download the 1x8/9 Wiring Diagram and check to make sure that all wires emulate the diagram.

What he said....