Running accessory power from battery

I have a 2005 Silverado Z-71. I would like to run power cabling direct to the battery for a ham radio transceiver installation, about a 10 amp draw at maximum. I was wondering if anyone has found a somewhat convenient way through the firewall to run power directly from the battery for your high power stereos or whatever other accessories you chose to install. Usually in the past I have been able to find a plastic or rubber plug in the firewall somewhere that was for an uninstalled factory accessory that I could pass the wires through but no luck with that as yet in this truck. Everything seems pretty tight and sealed up well on the firewall. Any ideas or experiences would be appreciated.

I have a 2005 Silverado Z-71. I would like to run power cabling direct to the battery for a ham radio transceiver installation, about a 10 amp draw at maximum. I was wondering if anyone has found a somewhat convenient way through the firewall to run power directly from the battery for your high power stereos or whatever other accessories you chose to install. Usually in the past I have been able to find a plastic or rubber plug in the firewall somewhere that was for an uninstalled factory accessory that I could pass the wires through but no luck with that as yet in this truck. Everything seems pretty tight and sealed up well on the firewall. Any ideas or experiences would be appreciated.

look under the vehicle on the driverside...

why not cut into the cigarette lighter circuit ???? a ham radio transmitter will use more than 10amps at 12 volts

Save your self the trouble and buy a male accessory plug for your unit. The cig lighter/acess. plug should be rated for your amp draw not to mention that it will be in plain sight so you can disconnect when not in use.
Otherwise I have gone through the emergency cable boot using an awl to poke through it.

Save your self the trouble and buy a male accessory plug for your unit. The cig lighter/acess. plug should be rated for your amp draw not to mention that it will be in plain sight so you can disconnect when not in use.
Otherwise I have gone through the emergency cable boot using an awl to poke through it.
Thanks for the ideas.
I will check out the emergency cable boot. That might work well and is off to the side as well.
Better off going directly to the battery than not. Currently I am not and do get some alternator whine and windshield wiper motor noise in the transmitted signal. I have a noise filter in line with the power cables and it has taken most of it out but not all of it.
If anyone has any other ideas I'd still like to hear them.