Bosque Bill
Senior Member
My truck didn't come with an XM Radio option and thought it would be entertaining to listen while driving the empty highways out west and while camping far away from terrestrial stations with music I'd like to hear or even baseball games!
I wanted a cleaner installation than simply plugging the radio's power adapter into the dash mounted 12v power socket.
My idea was to install a power socket behind the dashboard and out of sight. I was afraid it was going to be a major job to tap into a power circuit until I found a youTube video showing an installation using an Add-A-Circuit™ fuse tap.
This method will work on any vehicle.
It would be easy to get to the fuse box behind the dash and I wouldn't have to worry about drilling holes or going through the firewall or any of that scary stuff. The late model Tacoma's use a low-profie, mini-blade fuse. Auto parts stores and Amazon only carry the Add-A-Circuit taps for standard mini fuses (ATM) and full size ATO bladed fuses. I was able to find the low-profile equivalent on eBay.
To use the fuse tap, you remove a fuse from the fuse box and snap it into the bottom position in the tap; you add a new fuse in the upper position to protect the circuit you are adding. It was a little difficult installing the fuses in this cheap Chinese fuse tap.
I installed the tap in the fuse position listed as ACC which has 12 volts once you turn the key. Many of the other fuses are only energized when the circuit is energized, so for example the rear power window fuse is not live unless you are raising or lowering the rear window (not very useful in an Access cab, but it has a fuse nonetheless - I think this can be treated as a spare fuse for emergency use down the road.)
The pig-tail on the fuse tap has a wire crimp installed; I had to cut off the spade lug on the red wire from the power sockets, strip the end, insert it and crimp.
You need to find a place to terminate the black ground wire from the power socket. There was a mounting bracket just below the fuse box. I loosened the mounting bolt, slid a forked lug with about 6" of wire soldered on to it and tightened it down. I was able to match wire lugs, but you may splice the wire how ever works for you.
There was a convenient hole in a bracket just behind the hood release lever. I mounted the dual power socket by one of its mounting holes using a small bolt, nut and split washer. It's very light so I'm sure one small bolt will be enough.
Be very careful where you route the wires. By mounting the socket near the fuse box, there was no difficulty with those wires. Since the power wires from the radio plug/adapter need to run across to the radio, be very careful not to allow them to tangle with or get pinched by brake or gas pedals. I routed the wire next to the steering column, attaching it to the plastic with gaffer's tape; I then routed it behind the fiber mat keeping it below the velcro that attaches the mat to the flooring. Extra wire was tied together and left behind the mat. When I came up from behind the mat I routed it toward the center console and held it down with gaffer's tape to keep it away from any possibility of tangling with feet or pedals.
Parts List
Low-profile, mini fuse tap from modprosales store on eBay $10 with shipping
Custom Accessories 10242 Auxiliary Twin Power Outlet from Amazon $6.50 - I chose a dual socket in case I want to plug a GPS Nav or other accessory in without using the dash sockets.
misc hardware and wire
Fuse Tap without fuses installed:
Fuse Box behind dash with access drawer removed:
Fuse Box with tap installed (Note: this wasn't the final position of the tap.)
Power Sockets:
XM Radio - you can see the power wire and antenna wire running off to the left and diving behind the dash. If I decide to keep the radio in this location, I may remove the center console, drill a hole in the little well behind the radio and route the wires though the drilled hole. The radio audio plugs into the Aux socket, so no FM transducer is needed:
I wanted a cleaner installation than simply plugging the radio's power adapter into the dash mounted 12v power socket.
My idea was to install a power socket behind the dashboard and out of sight. I was afraid it was going to be a major job to tap into a power circuit until I found a youTube video showing an installation using an Add-A-Circuit™ fuse tap.
This method will work on any vehicle.
It would be easy to get to the fuse box behind the dash and I wouldn't have to worry about drilling holes or going through the firewall or any of that scary stuff. The late model Tacoma's use a low-profie, mini-blade fuse. Auto parts stores and Amazon only carry the Add-A-Circuit taps for standard mini fuses (ATM) and full size ATO bladed fuses. I was able to find the low-profile equivalent on eBay.
To use the fuse tap, you remove a fuse from the fuse box and snap it into the bottom position in the tap; you add a new fuse in the upper position to protect the circuit you are adding. It was a little difficult installing the fuses in this cheap Chinese fuse tap.
I installed the tap in the fuse position listed as ACC which has 12 volts once you turn the key. Many of the other fuses are only energized when the circuit is energized, so for example the rear power window fuse is not live unless you are raising or lowering the rear window (not very useful in an Access cab, but it has a fuse nonetheless - I think this can be treated as a spare fuse for emergency use down the road.)
The pig-tail on the fuse tap has a wire crimp installed; I had to cut off the spade lug on the red wire from the power sockets, strip the end, insert it and crimp.
You need to find a place to terminate the black ground wire from the power socket. There was a mounting bracket just below the fuse box. I loosened the mounting bolt, slid a forked lug with about 6" of wire soldered on to it and tightened it down. I was able to match wire lugs, but you may splice the wire how ever works for you.
There was a convenient hole in a bracket just behind the hood release lever. I mounted the dual power socket by one of its mounting holes using a small bolt, nut and split washer. It's very light so I'm sure one small bolt will be enough.
Be very careful where you route the wires. By mounting the socket near the fuse box, there was no difficulty with those wires. Since the power wires from the radio plug/adapter need to run across to the radio, be very careful not to allow them to tangle with or get pinched by brake or gas pedals. I routed the wire next to the steering column, attaching it to the plastic with gaffer's tape; I then routed it behind the fiber mat keeping it below the velcro that attaches the mat to the flooring. Extra wire was tied together and left behind the mat. When I came up from behind the mat I routed it toward the center console and held it down with gaffer's tape to keep it away from any possibility of tangling with feet or pedals.
Parts List
Low-profile, mini fuse tap from modprosales store on eBay $10 with shipping
Custom Accessories 10242 Auxiliary Twin Power Outlet from Amazon $6.50 - I chose a dual socket in case I want to plug a GPS Nav or other accessory in without using the dash sockets.
misc hardware and wire
Fuse Tap without fuses installed:
Fuse Box behind dash with access drawer removed:
Fuse Box with tap installed (Note: this wasn't the final position of the tap.)
Power Sockets:
XM Radio - you can see the power wire and antenna wire running off to the left and diving behind the dash. If I decide to keep the radio in this location, I may remove the center console, drill a hole in the little well behind the radio and route the wires though the drilled hole. The radio audio plugs into the Aux socket, so no FM transducer is needed:
