Is a 12v accessory port properly grounded?

[TFin04]

All,

I'm looking to finalize an installation of a Cobra 29 in my 2008 SIlverado. There is a very convenient 12v power supply in a lower storage compartment that I could plug into. Is this way of powering a radio ideal/recommended? Will I get better performance by running to the fuse box, or direct to the battery?

For reference, the rest of my set up will be a 4' Firestik II mounted in a stake pocket mount on the bed. The wiring will travel under the cab and back up to the radio.

Any recommendations would be great.

[231]

For a Cobra 29 it'll probably be okay. If you end up with a high noise level from the electrical system (and devices) you can always re-wire it. I personally prefer going directly to the battery with both leads...but many here don't do that and have good results. Every installation is different. Make sure you tune the antenna as well. Many of the pocket mounts don't achieve a good enough counterpoise connection for the antenna to work properly. It may be necessary to run a secondary ground strap from the mount to a better counterpoise connection point. But you won't know until you go to tune it.

Good luck.

[Radar-DLDN]

Generally it isn't ideal and running directly to the battery is the recommended way to go. It cuts down on interference from the dozens of things in a modern car/truck that cause interference. However it will work and if you wanted to hook it in temporarily to see how it sounds give it a try. I'm using mine right now until I get the radio permanently wired and you can hear the engine running very clearly over the speaker.

[BobCB]

Sometimes it even depends on the radio used. I once hooked a Cobra 10 up in my car using the cig lighter. It literally picked up every single bit of electrical interference there was inside the car. When I tried a Midland 75-822 it was just as quite noise-wise as my base is. The only interference it would ever pick up was from power lines overhead as I passed below them.

I say give it a try. If it doesn't work it will be easy to re-wire it to the fuse box or battery.

['Doc]

If that accessory power thingy is delivering 12 volts then I'd have to say it's adequately 'grounded', it's working. That doesn't say anything about it being adequately 'filtered', if it is at all! I didn't have any problems with getting power in a Silverado that I owned. There was some noises at times, but that's about normal and can be 'handled' in several ways. The biggy would be if that power tap can deliver the required current or not. That 'adequate power' is one reason why a separate power line (a large one for future expansion?) is a good idea.
- 'Doc