Audio Interrupt for Stereo with 2-Way Radio

The power input is from the receptacle at the top right. The 2nd plug down is the power and ground for just the CBM-U4. The 3rd plug is power and ground for TDS-15A and the 4th plug is for the radio with the power for it coming from the 3rd plug from the TDS-15A.

The brown wire is going in between the 2nd and 3rd plugs

 

Also to note, the power input wires for both the CBM-U4 and the TDS-15A have a built in fuse

 

Fuse should be as close to input wire, no need for branched fuses.
What amperage did the fuse holder come with?

 

3A for the CBM-U4 and 15A for the TDS-15A

 

You plan on running juice from battery to cab?

 

Yea, planning to run a 4-wire cable through the firewall for this.

Here is a picture of the entire setup hooked together. The cable coming in from the top will be the cable to the battery. The open plug on the right will be to the radio.

 

Easy to find glass fuses where you're at?

 

I have a few of them stocked. But I'm thinking of when I add in a dual battery system to the truck, I'm going to put in a BlueSea fuse block in the engine so I can use the standard blade fuses and have the fuses easier to access and I can just get rid of the fuses from the harness portion

 

Raining outside today so didn't get a change to install, but Rogus said the CBM-U4 does not have to be powered on for the stereo to play audio to the speakers and that the CBM-U4 only draws a few micro amps (he did not specify exact amperage)

 

That's why I drew it tied to the Truck radio juice & ground. Leaving the HF radio juice and ground on it's lonesome.(via the TDS)

 

I actually didn't expect the CBM-U4 to be able to pass through when it's powered off. I'm guessing the normal closed cutoffs aren't that expensive to put in

 

Got the whole setup installed, tested, and it works great. The volume for the radio is adjusted on the radio, separate from the stereo volume. With a MXT275, the max volume through the 2 front speakers seems to be louder than the Midland external speaker that I had before.

Stereo audio cuts off and comes back on seamlessly during receive and transmit from the radio. The CBM-U4 has about a 2 second delay before resuming stereo audio (non-adjustable) after receiving on the radio and I adjusted the TDS-15A to have about the same delay after transmitting. Remember to test the functionality of the units and if your stereo system still functions as normal and adjust the TDS-15A per the instructions before you slap the dashboard and center console back together.

I tucked the speaker harness with the other factory wire looms that drops down the center channel behind the stereo unit


I tucked the CBM-U4 in the cavity behind the lower center dash switch/outlet ports


And since that cavity behind the lower dash could not fit both the CBM-U4 and the TDS-15A. I stuck the TDS-15A with some

$15 Scotch Extreme Fasteners by 3M, 1" x 4ft Heavy Duty Reclosable Fastener Roll, Industrial Strength Dual Lock Tape for Indoor/Outdoor Use, Weatherproof Adhesive, Holds Up to 10 lbs, Black

3M dual lock fastener in the small cavity underneath the removable cup holder right in front of the gear shifter. That cavity is just tall enough for the TDS-15A to sit in.

 

I'd add some carpet or similar to the TDS-15A, it gets really hot in the Transmission tunnel.
Also, some tie wraps to secure the harness from flopping about.

 

You think this

$75 Siless Liner 157 mil (4 mm) 51 sqft Car Sound Deadening Closed Cell Foam & Heat Insulation mat - PE Foam Sound Deadener Material & Heat Barrier

sound deadening & heat insulation closed cell foam will work if I like...idk...wrapped it around the TDS-15A? Planning to get some of this to put into the doors, floor and walls of the cab as a future project.

 

I don't know the temp range for that, but it might work. An thin & inexpensive kitchen hot pad of silicone would do.

 

I'll give that a shot. Thanks for all your help on this project!