Major sparks when reconnecting batteries

I have a Volvo 1999 VNL.My batteries died because I left an interior light on for several days. After successfully charging ( I had disconnected the positive cables but not the negative ones ) I tried to reconnect the cables to the baterry bank which resulted in major sparking. I removed the negative cables, reconnected the positive cables and tried to reconnect the negative ones which resulted in major sparks and a whirring sound from the engine.
Can anyone diagnose my problem?
Thanks for your help.

 

You'll get arcing from connecting or disconnecting batteries.....That's normal....
The engine sound...Your starter solenoid closed?

 

You got one backwards!

 

C'mon...even in MA...it's after noon....should be open....maybe late hours for Sunday!

 

Yep....I missed that....Good catch....

 

Nope...NM and AZ...No running on Sunday...for me anyway....

 

Thanks for the quick replies.
It is definitely wired correctly since the cables are so stiff, color coded and of a limiting length it would be nearly impossible to screw up the cable connections.
It does sound like the solenoid is stuck open or a relay is open(?). Every time I touch the negative, heavy cabled ground to the battery there's definitely the sound of a motor turning over.

 

I tell ya what will fix it take a metal cresent wrench and touch both terminals at once.

 

Oh yeah...that sure will "Fix" something alright....

 

If your tractor is equipped with a load disconnect switch, try shutting that down before connecting your cables.