Small Engines (Lawn Mowers, etc.): ride on mower battery, key switch, wire harness

Question
hooked up ride on mower battery backwards and started mower, made a bed noise when i started it and srtaight away i realised what i had done. replaced with a new battery and it starts fine, but now when i turn ride on off and leave for a week the battery is flat when i go to start it. PLEASE HELP !!!

Answer
What is the engine brand, model, type and code number.  It is very possible, and likely, that the rectifier was damaged.

The link below does a good job describing how to test diodes (rectifers):

http://www4.briggsandstratton.com/miscpdfs/RNT/alternator_replacement.pdf

I would start trouble shooting by checking the fuse in your wire harness...they all have a fuse.   If the fuse is good then check the rectifier.  If the rectifier is good then check the key switch.

Let me know what you find.

Eric