I have a jet ultra3 wheel chair...the batteries went completely dead..I put in new batteries but now it wont charge...book says to call a tech if the batteries ever completely discharge..is there a protocal one must follow to get the charger to work after replacing the batteries or is the charger shot?

Its unusual for a charger that was working to stop working because you replaced the batteries. Does your chair operate correctly with the new batteries? If so then I would check the connection of the on-board charger at the controller box located in the front base section ahead of the batteries. Trace the cable from the charger to the controller and make sure it didn't come unplugged from the controller. Your red light on the charger would still light up but you would never charge the batteries. Now if you can locate an off board charger (borrow from a friend or neighbor that has one or borrow one from your local provider) plug it in the charger port located under the front of the joystick and see if the batteries will get fully charged that way. If you can't find any cable problems with the on-board charger and the off-board charger charges the batteries then there is a problem with the on-board charger or the charging system through the controller. It would be cheaper to purchase an off-board charger if the borrowed one works than try to replace the on-board charger. Hope this helps