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constant 12 volt power supply?

Posted: May 26th, 2010, 1:08 pm
by red17
im in the process of adding power door locks to my mx3, and the instructions say tohook it up to a constant 12 volt power supply. where on my car can i find this?

Re: constant 12 volt power supply?

Posted: May 26th, 2010, 2:19 pm
by umcamara
There are multiple throughout the vehicle. Get yourself a 12 volt test light if you don't already have one, and probe for 12 volts with the ignition off and key out of the ignition. The positive terminal of the battery is one, you'll find many at the cabin fuse box, behind the radio, the ignition switch. Take your pick.

Make sure you run an inline fuse, especially if you end up going straight to the battery (which would be dumb), and whenever tapping into a heavier gauge wire with a lighter gauge one.

Re: constant 12 volt power supply?

Posted: May 26th, 2010, 3:21 pm
by red17
im not wanting to connect it to the battery. i want to connect it somewhere around the ignition, but i cant figure out where it goes. where exactly is the ignition switch?

Re: constant 12 volt power supply?

Posted: May 26th, 2010, 3:46 pm
by umcamara
red17 wrote:im not wanting to connect it to the battery. i want to connect it somewhere around the ignition, but i cant figure out where it goes. where exactly is the ignition switch?
Ummm... how do you start your car if you don't know where the ignition switch is??

Re: constant 12 volt power supply?

Posted: May 26th, 2010, 3:48 pm
by red17
I figured I would get an answer like that. I mean where would I tie the wire into on the ignition switch

Re: constant 12 volt power supply?

Posted: May 26th, 2010, 3:56 pm
by umcamara
Likely the black heavy-gauge wire. As I said, always test it with a test light first. Easier to find a constant power wire at the fusebox though, it's right there by the door boot that you'll be running wires through for the lock actuator.

Re: constant 12 volt power supply?

Posted: May 26th, 2010, 4:00 pm
by red17
OK I'll look at those places.
Also, I touched the power wire to thi battery, and I'm not getting anything at all.

Re: constant 12 volt power supply?

Posted: May 26th, 2010, 4:20 pm
by umcamara
What power wire? The actuators will have 2 wires coming from them, if you connect one to positive and one to ground, the actuator will fire. If you connect the wires in reverse, it will then fire the other way.

You have to use 2 single-pole double-throw relays to wire them up for door locks. Each relay will have 5 terminals.

Re: constant 12 volt power supply?

Posted: May 26th, 2010, 5:24 pm
by red17
i'll take some pictures and show you what im talking about tonight