radio intall to key switch

[milltown]

I know this has probably been asked somewhere before but I couldn't find it. I plan on installing a radio next weekend and was wondering how to wire it to the key switch. Can I just wire it to the switch instead of battery or do I NEED relays and fuse blocks? If I can't just wire it to the switch I have then I will just wire straight to the battery with an inline fuse. Thanks for the help.

[Universal_Mechanic]

IIRC, the keyswitch switches a ground. So you need to run a wire from the "on" side of the key switch to pin 85 of a 30a relay. Pin 86 should be battery 12v+ . So when you turn on the key you are supplying a ground to the relay and turning it on. You can then use pins 87a and 30 of the relay to complete the positive circuit to the radio. If you need help with relays, lemme know, I can prob find a nice diagram for ya at the12V.com

[Universal_Mechanic]

I was just thinking. Last time I did this, I used the 2 extra spots on the fuseblock. Both 10A fuses. One power wire from one fuse to pin 30 of the relay, the other power from the other fuse to pin 85. Then from the keyswitch to pin 86. Then from pin 87 to the radio power. I did something similar for a customer a while ago who wanted the turn signals/brake light/strobe/horn to only work when the key was on and that was the method I used. I just mounted the relay right next to the fuseblock, so then you only need to run two wires to the dash, one to the keyswitch (relay pin 86) and one to the radio (relay pin 87)

Diagram: http://www.teamrocs.com/images/techn...ay_diagram.gif