mike813
Well-Known Member
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Hardwire Midland MXT275 in R1S with rear 12V power tap
Sharing some details of my GMRS radio install into my R1S. Maybe some of these details will help you, or maybe this will entertain you, or maybe you can just skip this one and go on to the next. In any case, just sharing as I've benefitted in so many ways from the sharing of others. This first picture is my Rivian. It is dirty. Shouldn't yours be dirty too?
So my Rivian friends Mike and Todd invited me to a local off road event. For that event I needed a GMRS radio. I'm a Rivian driver, so I'm not going to do anything half way. Sure, I could have bought the handhelds, but why not by the high power Midland MXT575? I'll tell you why. Because that 50W beast has to be wired directly to the battery - 12V power through a cigarette lighter receptacle just won't cut it. But alas, Midland makes a goldilocks MXT275. Ordered from Amazon. This comes in a kit with a magnet mount antenna. Why the MXT575 and 275? Because all of the controls are in the mic - you can mount the head unit remotely, and run the mic (short for microphone) to a convenient location. The mics on these babies use standard ethernet cable - so I ordered a ethernet patch cable to extend the reach.
My R1S was at the spa (also known as the Orlando Service Center) so I was in a R1S loaner. The loaner had a 12V power receptacle under the dash, but I didn't want to cheat, so I went ahead and used my Cat 6 cable extender. I plugged the 12V into the 12V receptacle in the cargo area of the R1S, ran the antenna out the back through the liftgate, and ran the Cat 6 cable under the seats up to the front.
The MXT275 head unit actually fits great in the little cubby for the 3rd row seat (picture from mine, not the loaner).
And the antenna that comes with the MXT275 kit is easy to place on the roof. You almost can't even see it. Photo below, if you zoom in you might be able to see this little antenna. Details below on the larger antenna that I added later.
So I get my truck back from the Spa, go on vacation for a week, work for a long week, then on the weekend decide that I might as well find a more permanent solution to install this beast. I start browsing the forums and see people tapping the wires behind the 12V cigarette lighter plug for power. Why not do this too? It probably isn't recommended, but that's what Rivian gets for only giving me one 12V plug, and putting it in the rear cargo area. Is this a joke? If so not funny. So hardwire it is.
While I'm investigating this hardwiring, I notice that the area behind this power panel has a bit of room in it. I look at the area and say hmmm... maybe I can cram the MXT275 head unit and all the wires back there - super clean install. So that is the plan.
all spliced up
power check - it works.
power check - the cigarette lighter plug still works - hallelujah! (yes, I have a cigarette lighter plug for my valentine one, but since the only 12V receptacle in my truck is in the cargo area, I had to hard wire tap into the rear view mirror for power. RUFKM? But alas, that also worked fine. See other posts online for details on that one.
So here we are, all cleaned up, all hooked up. There is plenty of room behind this panel to slide all the wires (neatly coiled) and the head unit.
So I ran a CAT 6 cable with a receiving end (I assume we can't call it a female end anymore?) up to the front - behind the panels, under the third row seat, under my fancy floormats from Kanundrum's buddy, and up under the center console.
It was getting dark but I realized I had a flashlight in my door.
Semi finished product - the cable runs back behind this trim and back to the rear panel. That was an adventure.
I interrupt this post to bring you an unsponsored advertisement from Factor 55. If you're going to spend this much money on a truck, please don't use a cheap hitch pin. This is as good as it gets.
Look how the business end kind of slides down in this hole - very cool
If you are still reading this, shouldn't you take your hitch cover off and throw it away too? This is a recovery point from 4122
Back to our story. So I popped off some more panels for the antenna wire
And then tidied everything back up.
Of course I had to get the bigger antenna and magnet mount - this thing looks a little bit too big to leave up full time, in my opinion, but I plan to leave it in the rear cargo area by the window.
This is the more robust antenna and mount from Midland. By the way - some on the internet mention that it is important to have a good ground plane for antenna performance. This area here is metal - this is the best place for a magnet mount antenna (in my opinion). I also like the idea of mounting my antenna on the roof rather than on a lower mount, although as I said I will probably keep this magnet antenna inside the cargo area most of the time, maybe just inside the rear side window.
Funny but true story - I asked my wife if she could notice the antenna. She told me yes, and it looks stupid. She was talking about the dorsal fin. I told her that came with the truck and was always there. She insists I added it. Then she noticed the stubby GMRS antenna and she laughed out loud.
As long as you line the stubby antenna up with a palm tree when taking photos it doesn't look that bad. I took this picture on Tuesday, it was a hot august night.
Now here's what's really awesome. I was looking at various mounting options and I ended up using two-sided velcro. I stuck some of the "loop" side on the back of the mic and stuck the "hook" side on the ash, on both sides of the main screen so I can put the radio on the passenger side when I don't have a passenger, or on the drivers side when I do. First I wiped the ash with alcohol so the velcro tape would stick. Some people wouldn't want hook side velcro stickers on their ash - but those people aren't reading this article anymore anyway, are they?
I also saw some great posts about battery hard-wired power bus power solutions - I would love to do that someday. Hopefully someone will find a power source somewhere in the cab of these vehicles (fusebox? other power leads? Unused harnesses?) because it looks to be pretty tough to go through the firewall. Rivian, if you're listening, you should expect people to use these trucks. How about a factory/service center add-on for an auxillary power bus?
That's about it. Any questions let me know.
Sharing some details of my GMRS radio install into my R1S. Maybe some of these details will help you, or maybe this will entertain you, or maybe you can just skip this one and go on to the next. In any case, just sharing as I've benefitted in so many ways from the sharing of others. This first picture is my Rivian. It is dirty. Shouldn't yours be dirty too?
So my Rivian friends Mike and Todd invited me to a local off road event. For that event I needed a GMRS radio. I'm a Rivian driver, so I'm not going to do anything half way. Sure, I could have bought the handhelds, but why not by the high power Midland MXT575? I'll tell you why. Because that 50W beast has to be wired directly to the battery - 12V power through a cigarette lighter receptacle just won't cut it. But alas, Midland makes a goldilocks MXT275. Ordered from Amazon. This comes in a kit with a magnet mount antenna. Why the MXT575 and 275? Because all of the controls are in the mic - you can mount the head unit remotely, and run the mic (short for microphone) to a convenient location. The mics on these babies use standard ethernet cable - so I ordered a ethernet patch cable to extend the reach.
My R1S was at the spa (also known as the Orlando Service Center) so I was in a R1S loaner. The loaner had a 12V power receptacle under the dash, but I didn't want to cheat, so I went ahead and used my Cat 6 cable extender. I plugged the 12V into the 12V receptacle in the cargo area of the R1S, ran the antenna out the back through the liftgate, and ran the Cat 6 cable under the seats up to the front.
The MXT275 head unit actually fits great in the little cubby for the 3rd row seat (picture from mine, not the loaner).
And the antenna that comes with the MXT275 kit is easy to place on the roof. You almost can't even see it. Photo below, if you zoom in you might be able to see this little antenna. Details below on the larger antenna that I added later.
So I get my truck back from the Spa, go on vacation for a week, work for a long week, then on the weekend decide that I might as well find a more permanent solution to install this beast. I start browsing the forums and see people tapping the wires behind the 12V cigarette lighter plug for power. Why not do this too? It probably isn't recommended, but that's what Rivian gets for only giving me one 12V plug, and putting it in the rear cargo area. Is this a joke? If so not funny. So hardwire it is.
While I'm investigating this hardwiring, I notice that the area behind this power panel has a bit of room in it. I look at the area and say hmmm... maybe I can cram the MXT275 head unit and all the wires back there - super clean install. So that is the plan.
all spliced up
power check - it works.
power check - the cigarette lighter plug still works - hallelujah! (yes, I have a cigarette lighter plug for my valentine one, but since the only 12V receptacle in my truck is in the cargo area, I had to hard wire tap into the rear view mirror for power. RUFKM? But alas, that also worked fine. See other posts online for details on that one.
So here we are, all cleaned up, all hooked up. There is plenty of room behind this panel to slide all the wires (neatly coiled) and the head unit.
So I ran a CAT 6 cable with a receiving end (I assume we can't call it a female end anymore?) up to the front - behind the panels, under the third row seat, under my fancy floormats from Kanundrum's buddy, and up under the center console.
It was getting dark but I realized I had a flashlight in my door.
Semi finished product - the cable runs back behind this trim and back to the rear panel. That was an adventure.
I interrupt this post to bring you an unsponsored advertisement from Factor 55. If you're going to spend this much money on a truck, please don't use a cheap hitch pin. This is as good as it gets.
Look how the business end kind of slides down in this hole - very cool
If you are still reading this, shouldn't you take your hitch cover off and throw it away too? This is a recovery point from 4122
Back to our story. So I popped off some more panels for the antenna wire
And then tidied everything back up.
Of course I had to get the bigger antenna and magnet mount - this thing looks a little bit too big to leave up full time, in my opinion, but I plan to leave it in the rear cargo area by the window.
This is the more robust antenna and mount from Midland. By the way - some on the internet mention that it is important to have a good ground plane for antenna performance. This area here is metal - this is the best place for a magnet mount antenna (in my opinion). I also like the idea of mounting my antenna on the roof rather than on a lower mount, although as I said I will probably keep this magnet antenna inside the cargo area most of the time, maybe just inside the rear side window.
Funny but true story - I asked my wife if she could notice the antenna. She told me yes, and it looks stupid. She was talking about the dorsal fin. I told her that came with the truck and was always there. She insists I added it. Then she noticed the stubby GMRS antenna and she laughed out loud.
As long as you line the stubby antenna up with a palm tree when taking photos it doesn't look that bad. I took this picture on Tuesday, it was a hot august night.
Now here's what's really awesome. I was looking at various mounting options and I ended up using two-sided velcro. I stuck some of the "loop" side on the back of the mic and stuck the "hook" side on the ash, on both sides of the main screen so I can put the radio on the passenger side when I don't have a passenger, or on the drivers side when I do. First I wiped the ash with alcohol so the velcro tape would stick. Some people wouldn't want hook side velcro stickers on their ash - but those people aren't reading this article anymore anyway, are they?
I also saw some great posts about battery hard-wired power bus power solutions - I would love to do that someday. Hopefully someone will find a power source somewhere in the cab of these vehicles (fusebox? other power leads? Unused harnesses?) because it looks to be pretty tough to go through the firewall. Rivian, if you're listening, you should expect people to use these trucks. How about a factory/service center add-on for an auxillary power bus?
That's about it. Any questions let me know.
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