Positive Battery Cable Sparks When Hooking Up

[Allen Goodman]

After 30 years of sitting in a corn crib, I was able to get a 530 started again. It has 1088 original hours on a working tach. Everything is original. It had a mounted 237 corn picker on it's whole life. I bought it from the original family last summer up in Iowa. I did change it over from POS ground to NEG ground by reversing the coil wire and AMP gauge wires. When hooking up the POS battery cable it would spark like it's being grounded. I disconnected the BAT wire from the regulator and no spark. So my thoughts was the voltage regulator contacts were probably rusted shut from sitting all these years. So I took the generator in and had it rebuilt (new bearings, brushes, and regulator). Put the generator back on and attempted to hook up the battery, same thing "Spark" like it's being grounded. My battery post have several burnt marks now. Disconnected the BAT wire from regulator, no spark. What is going on? The tractor starts and runs fine.

 

[JIM MN]

You are talking about a John Deere 530 tractor? Why did you change the polarity to negative ground? A generator is positive ground with the regulator positive ground? You gain nothing going to negative ground. If you change to an alternator-regulator, the polarity would be negative ground, then you will get great charging at a slow engine RPM.

 

[wore out]

After 30 years of sitting in a corn crib, I was able to get a 530 started again. It has 1088 original hours on a working tach. Everything is original. It had a mounted 237 corn picker on it's whole life. I bought it from the original family last summer up in Iowa. I did change it over from POS ground to NEG ground by reversing the coil wire and AMP gauge wires. When hooking up the POS battery cable it would spark like it's being grounded. I disconnected the BAT wire from the regulator and no spark. So my thoughts was the voltage regulator contacts were probably rusted shut from sitting all these years. So I took the generator in and had it rebuilt (new bearings, brushes, and regulator). Put the generator back on and attempted to hook up the battery, same thing "Spark" like it's being grounded. My battery post have several burnt marks now. Disconnected the BAT wire from regulator, no spark. What is going on? The tractor starts and runs fine.

After the change of battery polarity did you polarize the generator BEFORE the first startup of the engine?

 

[Allen Goodman]

After the change of battery polarity did you polarize the generator BEFORE the first startup of the engine?

I did change the polarity before the first start. I'll do it again.

 

[wore out]

I did change the polarity before the first start. I'll do it again.

The points in the cutout relay section of your VR are stuck "closed". Starting the engine without first polarizing the generator can cause this to happen, but it sounds like you DID polarize the generator FIRST.

At this point, with the battery disconnected, take the cover off of the VR off and carefully pry the points apart and burnish them, don't get rough with a point file or sandpaper or emery cloth as the layer of "good" metal on the contacts is very thin (and probably has already been destroyed).

If so, likely the points will stick again and replacing the VR is the only option.

 

[Allen Goodman]

I just reversed from neg ground to pos ground. Still spark from the negative side now. I’ll take the cover off and take a look. Thanks

 

[wore out]

I just reversed from neg ground to pos ground. Still spark from the negative side now. I’ll take the cover off and take a look. Thanks

Make up your mind on the ground polarity! What you just did with the cutout contact points stuck polarized the generator back to (+) ground.

 

[Allen Goodman]

Make up your mind on the ground polarity! What you just did with the cutout contact points stuck polarized the generator back to (+) ground.

I was just experimenting. Repolarized when I changed polarity. I took the cover off VR, points were not stuck together.

 

[wore out]

I was just experimenting. Repolarized when I changed polarity. I took the cover off VR, points were not stuck together.

Still have the spark when connecting the battery cables and POSSIBLY jarring the cutout points open in the process?

 

[Paul_IN]

After 30 years of sitting in a corn crib, I was able to get a 530 started again. It has 1088 original hours on a working tach. Everything is original. It had a mounted 237 corn picker on it's whole life. I bought it from the original family last summer up in Iowa. I did change it over from POS ground to NEG ground by reversing the coil wire and AMP gauge wires. When hooking up the POS battery cable it would spark like it's being grounded. I disconnected the BAT wire from the regulator and no spark. So my thoughts was the voltage regulator contacts were probably rusted shut from sitting all these years. So I took the generator in and had it rebuilt (new bearings, brushes, and regulator). Put the generator back on and attempted to hook up the battery, same thing "Spark" like it's being grounded. My battery post have several burnt marks now. Disconnected the BAT wire from regulator, no spark. What is going on? The tractor starts and runs fine.

Sorry to go off topic but can you post pictures? I enjoy seeing original tractors.

 

[buickanddeere]

What would possess you to swap the polarity from the factory POS chassis ? Odds are that the cutout contacts are welded closed with the current surge when it started generating with a polarity opposite to that of the battery .

 

[JMOR]

What would possess you to swap the polarity from the factory POS chassis ?

He said, "I was just experimenting.". Sometimes experiments go "boom!".

 

[Tom in Mo.]

Barn find originals are almost nonexistent anymore. They are original only once. Put it back to positive ground as it should be.

 

[Boowah]

He said, "I was just experimenting.". Sometimes experiments go "boom!".

FAFO LOL!!