The first battery light keeps flashing when I turn on the control. I believe it is locked, but I have no idea how to get it unlocked. It is a Merits MP1 electric folding wheelchair.

May be a problem with the flasher relay, easy to change out and inexpensive, if not that then will need the wiring etc checked through

hi Roy , can you first confirm the controller type fitted ? located at the rear near the batteries, on most controllers , 9 flashes mean controller fault.

Regards

Make sure the connections are on correctly!

I’m happy to assist further over the phone at https://www.6ya.com/expert/bill_bcbb89783b08c489

Flash Code 2 indicates that the voltage is too high or too low. Check batteries and cable connections. Charge the batteries. If this fault occurs during battery charging, the charger is defective or not adjusted correctly. Empty batteries will charge. Dead batteries will not normally charge.

Your joystick is in lock mode. Call Merit to find out how to unlock it or a power wheelchair dealer.

Hi to unlock the shark joystick turn on the chair and press the horn button twice within 10 seconds of turning it on. This should unlock it for you. Hope this helps

This would suggest that the lock is getting a signal from the control board telling it to stay locked, which would explain why the "spin light" is on as the control board does believes the cycle has not finished its in your signal board sorry

The number of lights that are blinking indicate what the problem is. Visit this site to locate the type on controller on your power chair and you will be able to see that the blinking lights mean:
http://www.pgdt.com/scenter/diagnostics/diagvsi.html
Try to reset your manual brake release as this is a common problem.
If you continue to have a problem, contact your manufacturer or dealer for service. If your insurance purchased they power chair for you, they may also cover the cost of repairs.
Good luck!

Unlock vehicle. Enter vehicle. Close driver's door. Switch ignition ON and OFF. Remove ignition key. Press and hold unlock button. Press lock button briefly 3 times within 10 seconds keeping unlock button depressed. Release unlock button. Some models: LED flashes slowly for 10 seconds. Some models: Central locking system locks and unlocks rapidly to indicate correct programming. Repeat above procedure if central locking system does not work and LED does not flash or LED flashes continuously.

hello mate.. if it has stopped working you might want to check the battery first.. if you are sure that the battery is fine then consider reprogramming the fob to your car.. here are the steps to follow.. NISSAN

Remote Control Fob Procedures:

The Central Door locking is controlled by the Multi-Remote Control system which controls
the door locking, door super locking and emergency hazard reminders.

When the doors are locked and unlocked the unit flashes the hazard lights once for lock and twice for unlock.

A maximum of four remote controls are allowed to be programmed:

ALMERA
ALMERA TINO
PRIMERA
MAXIMA
MICRA
SERENA
VANETTE CARGO
TERANO II

Ensure all the doors have been unlocked, either by using a good transponder key or remote
control plip key.

Procedure:
1. Turn the ignition switch from Position 0 to ON 6 times within 10 seconds.
2. Next, turn ignition switch to OFF position. Leave key in ignition switch.
3. Wait 2 seconds then the system will enter programming mode and will flash the warning
lights twice.
4. Press and HOLD the unlock button on the Plip.
5. While pressing the unlock button, press the lock button 3 times.
6. Release the unlock button.
7. The warning lights will flash once to indicate successful programming.
8. Repeat procedure 4 to 7 for up to 4 plip key's.
9. When completed turn ignition ON, and the warning lights will flash 2 times.
10. Remove key, and check all plip key's for operation.
NOTE : The programming mode will stop when either the ignition is switch ON, 4 plip keys
have been programmed or no input signal either from the switch or plip keys has been received
for 120 seconds.

http://www.autokeysquad.com/nissan-fob-programming

i hope this can help you.. :)