who has their hour meter in the engine room and how does it get wired in?
and do you have any pics of how its mounted?

My hour meters are dash mounted. Wish I could help with the wiring, but haven't done it before. Just another task on the list that I'd like to learn. Hopefully the other guys will chine in.

Good luck...

It's really nice if you wire them through an oil pressure switch so that if you accidentally leave the keys on they won't accumulate time.
Most of them are just wired to the ignition switch.

That is kind of what i'm looking for.
It would be a pain to run wiring from the dash back to the engine bay.

Pick a place to use for a 12v supply point, run a fused wire to the hour meter and wire the other hourmeter terminal to the oil pressure switch. You can get an internally or externally grounded pressure switch. I prefer the internally-grounded switch as it only has one terminal and cuts down on the installation time.

If you wire it through a normal pressure switch you would need a relay to change it from normally closed to open . Oil pressure switches are closed with no pressure. So the hour meter would not get power when there was oil pressure. I added one to old boat and no pics of that and my current boat has it integrated into the tach. But last year I added one for a buddy in his engine compartment, just made small little bracket from 1/4 starboard and used the lifting bracket for the bracket. He had the rectangular meter, it fit better. I will try get a pic of it and post it.

You can buy normally-open as well as normally-closed switches. Normally open is the one to buy.
Wag Aero sells the switch you need as most aircraft have this type of hour meter setup.
Their part number is A-055-000 and the website is www.wagaero.com

Oh, opps didn't know then existed. Thats the way to go ,plus I forgot to add the part about the fused 12 volt source.

By the way, that switch is rated to 100 psi.

Here's another one at Van's Aircraft, scroll down to the lower part of the page where the hourmeter and switch are both listed.
http://www.vansaircraft.com/cgi-bin/...duct=vans-tach