So I finally got around to installing my FT-7900R in my F-150 after having it sitting on my desk for like 6 months just doing simplex around the house. Got the power leads run direct to the battery with an inline fuse, used 12 gauge wire which I think is fine for this radio, and mounted the main body under the seat with the control head up on the dash. Overall pretty happy with how it turned out except for a couple things.

First thing is I'm getting some ignition noise on 2m, not terrible but definitely there when the engine is running. I grounded the radio chassis to a bolt on the firewall, thought that would handle it but it didnt really. The noise goes away completely when I shut the engine off so its definitely coming from something in the vehicle. Not sure if its the alternator or the injectors or what. Tried moving the antenna coax away from the power wires and that helped a little bit.

Second thing is I mounted my NMO antenna on the roof but I ran the coax through the door jamb and I'm wondering if thats going to be a problem long term. It's got a bit of a pinch point. Tape it up real good or should I redo it completely through the firewall somehow.

Running into any of these issues with your mobile installs? Radio itself sounds great on the repeater when it does work, just want to clean it up a bit.

The ignition noise thing is super common and kind of a rite of passage honestly. Few things to try — first check that your antenna feedline shield is actually grounded well at the mount, a loose NMO mount is a surprisingly common culprit. Also if you haven't already, get a ferrite choke and put it on the power leads right at the radio, that cleans up a lot of stuff. Some guys swear by putting one on the coax too near the radio end.

For the coax through the door jamb I would honestly redo it if you can. I did that on my old Tacoma and within a year had a short that took me forever to track down. Most vehicles have a grommet on the firewall that you can sneak a coax through if you're patient and have a good fish tape. Way cleaner and you'll sleep better knowing its not getting pinched every time you open the door. The FT-7900 is a solid radio by the way, been running one for probably 8 years now with no complaints.

im going through basically the same thing with my install right now so following this thread. I ran mine through the door jamb too and now im second guessing it lol. For the noise have you tried a noise filter on the power line? i picked up one of those Icom mobile filters cheap on ebay and it helped with my old radio. not sure if it matters what brand the filter is really