Max current from accessory side?

[Sailing Santa]

I’m planning out my install of the ham radios on paper first and an wondering if I can pull 20 amps switched somewhere? Many law enforcement radios routinely suck large amounts of current, so it’s not without precedent that high-power radios are installed in Mopar.
It seems more likely that I’d use the ignition accessory side to power a relay/solonoid to then pass on the current. Any suggestions as to where I should tap in?

2016 2500 Ram Cummins

WK4T

 

[GeometryFletch]

Exactly what radio are you installing? Dual Band or HF? If you need to pull 20 amps that's definitely a BIG mobile radio, nothing wrong with that, just wondering which is why I ask "exactly" what radio we are working with.

20 amps @ 12v = 240 watts max
15 amp @ 12v = 180 watts max

My set-up came with a POS and NEG with in-line fuses, I went straight to the battery and I turn my Yaesu 80 watt max (also has 0.5, 10 & 30 watt settings) on and off as needed. My radio has a APO (Automatic Power Off) feature if unused for 10m/30m increments, etc. It's handy. Maybe yours has that?

You can certainly install a relay switch if you prefer to have to turn on/off every time you start/stop the truck. This yes you'll need to tap into a wire that powers up when you start the truck..many to choose from. If the 12v socket powers on/off then that might be the simple/smart choice. If not, any 12v wire that has on/off start/stop will mostly work.

PM me if you have questions, I've wired up many radios and mounted as many antennas in my trucks for the Ham hobby.

 

[Sailing Santa]

I’m running (currently [no pun intended]) an Icom IC-7100 along with an ID-5100… because I want everything. The current draw is for a planned linear install after. I’ve got the HF and VHF/UHF antennas on the bedrails done. An extra run of RG8X goes back to terminate above the 5th wheel connectors in the bed, terminating in an SO239 bulkhead connection. I’m trying to route all the cables into the cab so everything can sit behind and under the back seat. Finding that perfect entry point is today’s nightmare. I’m beginning to think I should pull directly off the main battery and have a relay in-line for control.

WK4T

 

[Mister Luck]

If you are not aware mobil electronics in (most) police “shops” are so extensive that in summer service the A/C works overtime and the vehicle can not be shut down and the alternator needs to be running continuously.
My advice is to run a dedicated capacitive system to power your radios.
(12v deep cycle battery with a large capacitor)

Do I need Capacitor?

www.the12volt.com

 

[Sailing Santa]

Well aware, but no. The current requirement here is intermittent and continuous running isn’t necessary. I have a secondary 50ah LiFePo4 battery behind the seat as kind of an UPS anyway. Worked on Motorola gear for years. I just wish I had this technology back then.