Quote Originally Posted by gabi68 View Post
How should I connect the button, please?
Use my simple diagram above. The only thing you have to be careful of is polarity. The relay you selected has a built in diode, so the coil has a + and a - terminal. You connect - to your 12VDC - and switch to the plus terminal (this is the most common way of switching). When you push the button the relay should release or pull, depending on how you wired (NO or NC). I didn't look at your fancy button, so I have no idea if it is a single pole, or dual pole switch, or if it has both NO and NC contacts or not.

To be honest, I agree with the previous poster that you seem to be in a need of elementary electrical knowledge, because your questions regarding the relay and how to wire are really very basic. Try to read some basic information sheets because you will need it. You will also need a simple DMM and some basic electrical measurement knowledge. That is a minimum when you start wiring things. Whatever you do, DON'T TOUCH THE MAINS SIDE. Making mistakes on the low voltage DC side might burn some parts and generate some blue smoke, but making mistakes on the mains side might kill you. I don't think you have the knowledge to touch the mains side. I am not saying this to sound rude, but I think if you plan on doing any electrical modifications then your knowledge level must be increased to at least basic level of understanding electrical circuits and switching. You will need that knowledge constantly if you intend to make changes or trying to find and fix faults.