Wow, so I came across this forum while trying to track down answers to my electrical problems, have read anything relevant in all 17 pages and there's some great information here, thanks everyone. I have an excellent (but fairly beat up) little Previa van that the previous owner converted into a camper. I have named it Bubble and I used to love it until it became infested with gremlins... I've done a little bit of manual work on it (CV axel, ball joint) but I know nothing about electrics.

So from reading here I think I have a better idea of what might be wrong, but still confused as to whether I have one, two or three problems!

1) Sometimes about half an hour after I leave the car the headlights come back on, which then drains the battery. I thought I was going insane until I caught it doing it a few times. The switch is off, they are off when I leave the car, then they turn back on. Turning the key in the door switches them off. I think this may be related to the alarm, the wires to the horn have been cut so maybe that is going off too and I just don't know about it.

2) Doesn't start sometimes, no ticking over or anything. I think sometimes this is because the lights have drained it and sometimes because the battery terminals are/were loose and corroded. Sometimes jiggling the terminals works, sometimes it needs a jump. Cleaned and tightened them today, positive cleaned up okay, negative is very corroded and probably needs replacing.

3) The scary one. This morning it would not start, jiggled the terminals and it started up okay. Noticed on my drive to work that when I braked slightly hard the radio would skip for a second. At the top of a hill near my office it did this and then I lost all power to everything. Brakes still worked so I carefully went down the hill then pulled a no power steering turn into a side street and rolled to a stop. No lights, engine, speedo, wiper etc. Jiggled battery terminals to no avail. Came back with a coworker and cleaned and tighted them and it started up okay. No problems on the drive home but I'm scared of it now.

So I think I may have problems with my alarm, battery terminals and possibly the fuse box. Also my fuse box (haven't looked inside it yet as its dark and raining) is not mounted to my battery but is just dangling, which is probably also not good.

Its going to my mechanic tomorrow who is a really nice guy but not super knowledgeable about the Previa's weird things. So any advice as to what to ask him to look for would be very much appreciated.

Thanks
Jane