12 V Power Source

[wcdeane]

I am adding water injection to my SE, and I need a good 12V - 15 AMP source in the vicinity of the engine bay. The source must run through the ignition switch. Any suggestions.

[cnh1990]

Find a line with a lower current draw off the accessory switch to power a relay. Then use a fused line to the battery and then run this line through the relay. Much like how one uses a remote turn on for a audio power amp that draws a lot of current. It is much easier this way. I really don't like to add sorts of power consuming devices as the alternator is marginal as it is and will have to work harder.
Good Luck,
Calvin