How do I hook up the two batteries in a Vector 190 sport spotlight. I need to see a wiring diagram for the battery connections.

Quick look at the manual tells me that it is a 12v light, powered by two 6 volt batteries. This means that they must be connected in series. Identify the positive and negative terminals on each battery. You also need to look at how the power is supplied to the unit - i.e., are the batteries connected front to back? The jumper of one battery will connect to the negative terminal to the positive terminal of the second battery (this is a series configuration.) Make sure the batteries are oriented in the proper position in the unit before sealing it up.

The manual can be downloaded from here: http://www.manualslib.com/manual/185814/Vector-Sport-Spot-Vec190pob.html#manual