voltage question

[ADV]

I have just put a CB radio in my truck I have the positive wired to a wire behind the radio that turns on with the key. With the CB turned off if I turn the key to the on position my CB lights up for a second or two and shuts back off. I checked the wire voltage and right after the key is turned on it hits 18 volts then goes to 12 where and why am I getting a 18 volt spike? it happens every time I turn the key on. It just blew the fuse for the CB today.

 

[flareside_thun]

You need to have your cb hooked to a fused hot directly to the battery. Your radio draws more power than you think and just tapping into a hot wire is not the best way to go about that.

 

[GOOSE]

I would run off of the post of your solenoid, through a fuse right to your cb. There are many times you may want your cb on without the added draw of the rest of your accessories. Make sure the ground is good as well.