Lighting Kit for Rivarossi Passenger Cars

[Anonymous]

I'm new to model railroading and just installed a Walters Lighting kit into a Rivarossi Car. When all of the wheels are on the track it doesn't work, but if a couple of wheels or maybe it is the truck are touching the rail it will work. There is a contact problem but can't figure it out. Has anyone else had this problem and how did you correct it?

[8D]