This could be really simple? But I would appreciate any ideas

At first I thought it was the battery (as gets drained by the alarm, if I forget to disconnect battery) So I bought a new battery and installed.

It is now seems to be a short in system. As sometimes completely dead (no lights, no action) and other times all lights come on, but when I turn key all goes off. So assuming that system overloading somehow.

Thanks and regards

 

Sounds like a bad/dirty ignition switch. Does jiggling the key make any difference?

 

Battery terminals clean?

 

It sounds more like an ignition switch to me. Are all the lights dim when you turn the key to "run"