GMRS Midland MXT275

Alternator is likely the source. Look at installing a ground loop isolator on your radio. They are cheap, should clear it up.

I've used this on every 2 way radio install since my 4Runner when I endlessly chased alternator whine...

HogRider said:

Have anyone had any issues feeding power to their radio and getting a tiny bit of noise whine when the key is turned to on or if the engine is started?

I wired my MXT275 to Int2 and with ignition off if I turned power on and int2 on, radio works perfect. However with ignition set to on or engine is on. I get this whine that comes through. I connected the power to center cubby cig and engine on no issues. Also tried an external power station and no issues. I suspect the power from Int2 is capturing some noise? Is my best bet to hardwire to the battery? Was hoping to use the int2 switch to turn radio on off….

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I keep my entire MXT275 in the center cubby, where it is plugged into the cigarette lighter ‘power point’ there, and have had no issues. When the ignition is switched off I can still provide power to the radio by use of the PWR Switch on the overhead panel.

Ovrland Bill said:

I keep my entire MXT275 in the center cubby, where it is plugged into the cigarette lighter ‘power point’ there, and have had no issues. When the ignition is switched off I can still provide power to the radio by use of the PWR Switch on the overhead panel.

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Ya I used the center cubby for my first trip out and no issues and re-tested again with the new coax cable hidden away and no issues. I didn't know the center cubby 12v can be powered with the power switch. This will be my last resort if I all the noise isolator doesn't work. Thanks!

Thanks everyone. I got some ferrite ring coming tomorrow and if that fails going with Anand’s suggestion. If that fails again, I guess center cubby it is.

Ferrite ring failed…. I temp hook power from battery just for kicks… zero noise/whine. Now debating if I should even try the noise suppression or just wire the damn thing from the fuse box.

Just in case it helps anyone. I borrowed my friend mic and his upgraded mic from Midland... Still same issue. I finally gave up and tapped the 12V fuse for the center cubby cig lighter that was up in the front driver side fuse box. Pulled the wires to the passenger side, there 2 ground nuts down there. Put everything together, no whine at all. Moral of the story after a whole week of playing with this. If its for your radio, just wire the damn thing straight fromt the battery, or somewhere equivalent.
Now I got to figure out what to use INT 1&2 for.... I hooked up a USBA/C charger, but seems kind of useless, since there 2 more in the cubby and 1 more from the MXT275. Not sure why I would need a USB C to run off a switch.

Chose to go from passenger side, since I wanted to mount the radio under the passenger side footwell.


Follow the same path as one of the forum members. Remove the screws and the pull the coax under the trim.
Then I use the grummet to pull into the wheel arch than toward the rear passenger floor.


Groummet, poke a hole, pull wire, reseal.


Front passeger, you can remove all this and pull wire underneath.


Old wiring using INT2. I have since switch it to a fuse and no more mic whine when ignition is on.
Big red circle up top is where I have my Main Radio unit attached to.


Proclip with Midland Clip attached on

Super Information. Danke

HogRider said:

Just in case it helps anyone. I borrowed my friend mic and his upgraded mic from Midland... Still same issue. I finally gave up and tapped the 12V fuse for the center cubby cig lighter that was up in the front driver side fuse box. Pulled the wires to the passenger side, there 2 ground nuts down there. Put everything together, no whine at all. Moral of the story after a whole week of playing with this. If its for your radio, just wire the damn thing straight fromt the battery, or somewhere equivalent.
Now I got to figure out what to use INT 1&2 for.... I hooked up a USBA/C charger, but seems kind of useless, since there 2 more in the cubby and 1 more from the MXT275. Not sure why I would need a USB C to run off a switch.

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This is very helpful. THANK YOU for sharing this. I was going to mount this exactly as you did using INT2. I’m going to nix that. I’ll mount the unit under the rear seat and connect to the battery directly. That settles that as it relates to power.

As to the antenna mounting. Kinda hard to do better than what you have mapped out going aft. Did you consider mounting forward?

I just did something similar, although I mounted the unit in the center console cubby so that I could utilize the plug and play 12v outlet there. Also, I mounted the antenna in the same place, but chose to route the cable into the vehicle at the rooftop power outlet. I simply removed the grab bar (and the black plastic trim), pulled the deutsch connector apart and then had full access to the grommet leading into above the rear side window. I fished the wire all the way from there to below the passenger seat and then found a tiny chase at the center tunnel into the console. I drilled a small hole in the rear of the center console inner cubby, placed a rubber grommet - it turned out great.

Editing to add: I ordered a Midland MXTA26 6DB Gain Whip antenna to get the antenna above all of the crap on the roof of the grenadier. Not sure if this is necessary, since I'm not an expert on radio transmission, but I assume with antenna shown in the picture above, there might be some level of interference due to the roof rack, thule roof box, 270 degree awning that I have mounted. Let me know if you know, or have any thoughts.