When connecting or disconnecting the negative cable from the battery on my 2004 Fatboy, I always hear the same electrical sound I hear when turning the console **** to the ignition position. Note that I always make sure that all switches are in the off position, before I remove the negative cable, but despite that I still hear that sound. I also notice a little blue spark that jumps between the negative cable and the negative post as it is being removed. It doesn't seem to hurt anything and I've never had any dead battey problems, but it bugs the crap out of me when I hear that sound and see that little spark.

 

Probably the elc fuel pump...

 

I would not think the fuel pump would do it without the switch being on. Sounds more like a capacitor discharging.

 

Are you disconnecting the negative cable first? Mine always sparks a little too. That is normal.

 

I do not think it is the fuel pump as long as the ignition is off and the spark tells me you have a draw probably from a accessory that needs a charge to a capacitor like a clock or ?

 

it is normal. it has to do with the ecm doing its startup test

 

Thanks for the great info guys. This is why I love this forum.