RA062123

I would like to run a pump when my key is on, I have a 2002 e320 Wagon (with a battery in the passenger rear seat) and would like for it to turn on when I turn the key to the ON position. Does anyone know where the best place to tap into would be? The pump is located under the hood towards the front passenger headlight?

bbirdwell

Take a look at these.

Testcrash

So why do you want to run the pump when you turn the key to on? If it's the pump I think you are referring to, it run via a button on the climate control. It continues to circulate hot water to your heater after you shut down the car. I don't think it's intended to be running all the time, but I could wrong.

RA062123

I'm not referring to that pump lol :p I have supercharged my e320 and have a second intercooler pump

nelbur

Your cigar lighter comes on with the key and should have plenty of power unused. You should install a fuse to protect your wires as the fuse to the cigar lighter is likely way to large to protect the wires you will install.