Where to find an available 12V / 20A (or greater ampacity) point inside cab?

[stevecon]

I'm looking to install a 2-way amateur radio in my cab that requires 12V/20A circuit.

I've looked at the "add a circuit" type taps that you insert into a spare fuse location in the fuse block of the truck; but all I've found have woefully undersized 18 or 16 gauge wire to connect to. A proper 20A circuit requires a #12 gauge wire at a minimum. These products claim to supply 20 amps (or more) with only a 16 gauge or 18 gauge wire. Independent, reputable sources would tell you those smaller wires are only rated for circuits needing about half that amount.

Since I can't find a suitable tap - I'm looking to find a place in the cab that I can tap into that will not adversely affect the exisiting circuit. Surely, someone has been down this path before and has some insight. Ideally, the location of an unused 20 amp or larger wire would be perfect. I miss the days of the "Accessory Terminal" on the fuse block (and the High / Low Beam foot switch). Thanks in advance.

 

[kapinallinen2]

I'm looking to install a 2-way amateur radio in my cab that requires 12V/20A circuit.

I've looked at the "add a circuit" type taps that you insert into a spare fuse location in the fuse block of the truck; but all I've found have woefully undersized 18 or 16 gauge wire to connect to. A proper 20A circuit requires a #12 gauge wire at a minimum. These products claim to supply 20 amps (or more) with only a 16 gauge or 18 gauge wire. Independent, reputable sources would tell you those smaller wires are only rated for circuits needing about half that amount.

Since I can't find a suitable tap - I'm looking to find a place in the cab that I can tap into that will not adversely affect the exisiting circuit. Surely, someone has been down this path before and has some insight. Ideally, the location of an unused 20 amp or larger wire would be perfect. I miss the days of the "Accessory Terminal" on the fuse block (and the High / Low Beam foot switch). Thanks in advance.

There is none.
I did it the old fashioned way and ran AWG 10, might have been #8 from the EPDC in to the left side of the dash, where I mounted a fuse block to provide multiple fused hookups.
edit: the 50A in the first picture is for the Anderson connector.

 

[stevecon]

Ugh. I really hate the thought of drilling a hole through the firewall for this - given the number of spare / unused fuse locations on the fuseblock. I'm going to see if I can modify one of those "fused circuit taps" I mentioned above to provide a #12 hookup wire instead of the useless (for my application anyway) small wire. If I can't get it to go - I suppose I'll have to stuff a grommet into an oversized hole I'll drill in the firewall to bring some extra capacity into the cab as you've done. It's just hard to get motivated when the thermometer is showing single digits and I'll have to do this in my driveway. Where did you mount your GMRS radio? I have to decide between installng a Connect Systems CS-800D or a Radioddity DB50 (Anytone 588UV clone) in my truck. Both have remote control heads so I figured I'd mount the radio either under the rear seat or behind the rear seatback.

 

[kapinallinen2]

Ugh. I really hate the thought of drilling a hole through the firewall for this - given the number of spare / unused fuse locations on the fuseblock. I'm going to see if I can modify one of those "fused circuit taps" I mentioned above to provide a #12 hookup wire instead of the useless (for my application anyway) small wire. If I can't get it to go - I suppose I'll have to stuff a grommet into an oversized hole I'll drill in the firewall to bring some extra capacity into the cab as you've done. It's just hard to get motivated when the thermometer is showing single digits and I'll have to do this in my driveway. Where did you mount your GMRS radio? I have to decide between installng a Connect Systems CS-800D or a Radioddity DB50 (Anytone 588UV clone) in my truck. Both have remote control heads so I figured I'd mount the radio either under the rear seat or behind the rear seatback.

No need to drill, I cut a hole to the existing grommet left of the steering shaft.

 

[kapinallinen2]

Where did you mount your GMRS radio?

Made a DIY mounting plate and used RAM mounts with 1" ball system.

 

[stevecon]

No need to drill, I cut a hole to the existing grommet left of the steering shaft.
View attachment 210480

Hey - thanks for this photo of the grommet. I was looking into my radio specs and when transmitting - one of them requires 9A @ 50W so I can use the tap device. But I do like the idea of getting a higher capacity circuit into the cab and maybe using the tap to power a relay that drops power to the radio when the ignition / accesory "power off" timer expires. I'm curious - how did you get the antenna cable out of the cab?

 

[boogielander]

just tap a hole through the existing grommets. you gonna need to run the antenna cable anyways.

I did mine with a dedicated power and ground through the firewall (along with antenna cable) using 8AWG cables, run them to a BLUE SEA 6 SLOT fused distribution w/ negative, and run my HAM there. I also have a circuit breaker near the battery for this loop.I highly recommend NOT run your power through the truck's fuse blocks, because IF anything goes wrong you will cause a lot of damage to your truck, and with how sensitive modern trucks are electrically, creating an OUTSIDE loop for whatever you install is going to be the safest way.

Using the 8AWG cable method also opens the possibility for when you want to run more power hungry accessories like DC-DC charger for a power station that is charged while driving. I never understood why people don't want to go through the firewall... cut the existing gromet, run your wire, close the hole with silicone, and nobody will know. Or make a hole through firewall, put a gromet, and nobody will know. You will not even see it.

 

[kapinallinen2]

Hey - thanks for this photo of the grommet. I was looking into my radio specs and when transmitting - one of them requires 9A @ 50W so I can use the tap device. But I do like the idea of getting a higher capacity circuit into the cab and maybe using the tap to power a relay that drops power to the radio when the ignition / accesory "power off" timer expires. I'm curious - how did you get the antenna cable out of the cab?

Two RG-58`s, under the carpet, through a grommet and up to the bed.