Blu Blog
Truck Radio Aux Jack
Fri 12 April 2024I'm adding a 3.5 mm jack to my truck's radio so I can play stuff on it--only 4 years into owning the thing.
Taking the radio out was super easy. Just pull at the plastic cover in the truck, move it over to the side, and unscrew the radio. Then undo the harness for the radio, and pull it past the plastic cover.
Guides on the internet say to disconnect the airbag connector at the top of the plastic cover to make it easier to get the radio past, but honestly, that's such a pain in the ass. Since you need to disconnect the battery to avoid airbag detection problems. I was able to pull gently on the various cables and harnesses to get enough slack to maneuver the radio easily past everything.
Next step involved a bit of disassembly. Honestly, pretty straightforward. Look for the most "outward" thing and start undoing screws in it. Pull gently, try to suss out where it's being held in still, and look for screws there. Once I got the top loosened, the front panel was easily removed. Then, I could see my real goal was to remove the circuit board from the bottom of the largely-empty box.
Once I got the circuit board removed from the bottom of the box, I could easily see on the underside where the radio antenna input was and where the various traces for the audio out was to the harness. It's at this point that I failed to find my multimeter, and had to stop because it was 2 am and en't gonna be a store nearby that sells em at this hour, I guess.
Got a multimeter, tracked the speaker inputs back to the encoding chip that seems to output the signal. I think a decent place to solder the wires on is just right at that output. I've decided to mix together all left and all right--not worried about surround sound, just stereo from my aux jack. It could cause noise problems with multiple signals from the radio now being bridged, but I don't intend on using the radio. In the 4 years I've had the truck, I've never intentionally used the radio.
Potential problems, though:
- noise or signal bleed from bridging
- I may have misidentified the place the signals are actually coming from
- the radio volume control may not work with the encoding chip bypassed. I don't know if that's part of the signal into that chip
If I've messed it up, I can so far undo all my changes by just desoldering the wires. I also plan to leave the radio antenna uncoupled when I reinstall the radio just in case. Once everything is shown to work, I can recouple it to see if it still works. Then I can also have emergency radio access.