How to tap into ign?

[Hoffman5982]

Im wiring a relay and I was told to wire one of the prongs into the ign,or and switched source so that it only comes on when the car comes on. What is a good wire to hook it into? Sorry if this is a dumb question, Ive never messed with the electrical system of my car and instead of trying to figure it out myself and taking the chance of messing my car up, id rather do it right the first time. In the fuse panel in the engine bay, there is a solid light blue wire going to the audio 7.5 amp fuse. I was thinking this is the same as the remote wire that goes to the amp?thanks for the help

[bcar240]

What type of car is it? If you look in the electrical section of the factory service manual or can find a wiring diagram it will help find an appropriate wire. You probably want to tie into the accessory wire off the key switch (that is the one that cuts power during starting to allow everything to be available to the starter).

In my car's FSM which covers 91-94 240sx, the accessory wire is indeed blue and already powers two accessory relays in addition to some accessories/controls in the instrument cluster, but it could vary between models and I would make sure it is the same for your car. Once you find that, all you need to do is wire your relay between the acc wire and ground. There are also numerous wires that you could tie into farther downstream as well, such as the stereo power wire, but which ones would have to be checked on a case-by-case basis.

[PapaSmurf2k3]

clock, radio, cig lighter, fans... take your pick