help installing tv tuner

red wire is the accesory wire like the red wire the goes to the back of your radio.  this wire is any wire that has power when the key is in the accessory position.  the yellow wire is any wire that is constantly on... kind of like the memory wire for your radio.  the blue wire is supposed to be hooked up to the parking brakes.  this is to prevent your from watching tv when you are driving.  but that wire does not need to be hooked up for the tuner to work.  you didnt mention the ground wire.... so im assuming you know what to do with that.  btw... dont tap into the wires in the back of the radio unless you use a relay.

You do not need a relay behind the radio. Tuners draw almost no current and that should not be an issue. All you need is the keyed hot (red) and constant which is the yellow. As far as the blue wire if you meant brake terminal you can ground that wire, but I doubt you need it as it is only a tuner and not a flip out tv from the dash. If it is a screen from the dash you need to ground it for it to work on the DVD mode or tv tuner. Not legal but no one listens. You did not mention the ground either. Very easy to wire up.

DanDan

You have to ground that wire, because the tuner will not come on unless it is grounded. This feature is used for the ER brake because it is illeagal to WATCH TV and drive, so you will need a CONSTANT ground instead of the ER brake swicthed ground.

Yes I don't install relays either for that application. Instead I just replace the radio fuse which is usually 5 amps to a slightly higher fuse (7.5amps). I know that goes against mecp rules but...anyhow.. just in case since sometimes I hook the dvds to the same wire. I've never had a problem and I've installed many systems that way.