[ibheath]

On one of my remotes the lock don’t work, and the other which worked but had been lost for several months under a pile of paper and now showed up don’t work at all. Are there batteries inside them? How to change them? (10 yr old car. Visit a dealership and pay them >$100?)

It is a coin style battery, usually you can get two for under $5 at lowes/home depot. Walgreens/CVS/etc carry them too. Just unscrew the back, open, pull the battery and read the number on it.

[Revolting cat!]

The problem is that the remote is not screwed together but more or less sealed plastic.

[smokingfrog]

My Mazda remote is not so simple. I think it was designed by the Rubik’s cube guy.