MK5 SPJ+ Joystick will not shut off

SOURCE: I have a invacare The joystick mk5 will not lite up batt. are new

Some chairs, like the M91 are a real bear to replace the batteries and connectors can get knocked loose in the process. First, using a voltmeter you need to see if the controller is getting power. On the DC setting, use voltmeter at the three-pin female connection at the joystick that is the charging port. The two pins that are opposite each other are the "hot" pins, and your meter should read about 25 volts, +- 2 volts. If its 0, there is a connection that isn't made from the batteries through to the controller, or the controller or joystick is shot. If you do have power to the joystick, then it's probable that the joystick is shot. A new one from Invacare is pricey, around $1,000.00 I have found a new site that can repair most makes. I have not used them, so cannot vouch for their work, but give them a call and see what you think.
http://www.flightsystems.com/cart_controls/wheelchair_powered_scooter_market_cart_controls.htm

If you don't have power, start at the terminals from the battery, and follow each wire back to the power control box, unplug and replug firmly as you work your way back. Check all fuses on the way. Then check all of the other connectors inside the chair, unplug, and reconnect again. Unplug and reconnect the wires leading into the power control box, and then restart chair. If no lights still, then the power control module is probably the culprit, but the address above fixes those too. The joystick and the power control module work together to make the chair operate safely. Good luck