I am installing a radio transceiver in a '99 F250 SuperDuty regular cab 5.4 automatic. I need to run the leads straight from the radio to the battery (fused, of course). There are two 12ga wires, hot and ground. Radio will be mounted near the center of the dash.
What is the best way to get the power leads thru the firewall? Is there already an allowance for extra wiring, or where is the best place to drill and grommet?
I'm pretty sure that the 99s have an oval shaped grommet just above the floormat on the passenger side. It is installed from the factory from the front side, I usually push them out from the inside, pick it up off the floor, poke my wires thru, and re-install it from the inside. If you use a stiff wire as a guide, and push it from the inside, your wires will run under the air conditioning/heater housing, & end up right at the battery. I'm not sure if this grommet is still there on the new trucks, but I know it was there on the 2000-05 ones, & the 99 should be the same. The company I work for switched brands in 05 so I haven't had to install a radio in one of the newer trucks, but the SDs were one of my favorites for installing radios in. Another tip, that is a little bit based on your trim level - if your radio is a 2 piece unit (main radio and separate control head) - there is a channel formed in the floor pan beneath the passenger seat from under the seat to the area under the door sill where the factory wiring us run. You can mount the main part of the radio under the seat, fish your wiring through the channel under the floor mat (or carpet), and run it under the door sill up to the firewall. Keeps everything out of site and pretty well protected. You don't even have to cut the floor mat, there is a pre-cut hole from the factory.
Check around your steering column under the hood. My 02 has a few wires near there that area sealed off on the ends. If you look under the dash they are sealed off on the inside too. They're pass through wires for customer access for wiring up things just like you're talking about.
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Chris
2002 F350 6-speed 444 CID. XLT, Heated Seat, 270,000 & counting. 6637 w/ Pete's armor. Cold air set up for 6637
“Good judgment comes from experience, and a lot of that comes from bad judgment.” Will Rogers
I ran 10-gauge wire directly from the battery through a grommet on the driver side firewall.
I would use 10 gauge minimum. It's fused by the battery (pos and neg). Also my 2/440 ham xcvr is fused at the radio. See these sites for more info.
Thanks for all the help. I went with broncobob's suggestion, pulled back the carpet on the pass side, and sure enough, there was an oval plug. Pushed it out, and it didn't drop to the shop floor, though...area was boxed in. There were a few holes that opened from the boxed in area to the open space right behind the fender liner, so I stuck a grommet in a hole and passed the wire thru.
Worked great, now gotta get the radio mounted up. (Icom 2200H, btw).
