12v switched power in engine compartment

Does anyone know if there is a switched 12v power source inside the engine compartment of a 2008 Toyota Sequoia? It is a very low current draw (less than 1 amp).

I know that I could try to run a wire from the cigarette lighter inside the cab back through the firewall into the engine compartment but it seems that there must already be some wires in the engine compartment that will do the job.

I tried looking for a switched power source in the fuse/relay box next to the battery but every fuse seems to be "on" all the time (not switched on/off by the key). The service guy at my dealer told me that the switch is on the ground side of a lot of the electrical components, such as the headlights (i.e. the 12v positive side is on all the time).

A lot of the components are the same as the Tundra, so if you have this information instead, I'll give it a try.

Thanks!!!!!
- Brian

Can't ALL be constant, look at your wiper motor, one of those will be on all the time with ignition.