Jerrod Jones
Former Editor, Off Road
It’s tough cutting into a new vehicle. For those that own something made in the 21st century, we can understand getting squeamish when you have to start cutting holes in something like a pristine Wrangler dash, while wallowing out firewall holes to pass wires and bulky connectors through for whatever accessories you want to run in your JK. Not only can things get messy, but it can get crowded under that dash as more and more wires are run and you slowly build what electrician’s like to refer to as a “rat’s nest.”
The Trail Rocker’s fuse and relay center uses a weatherproof housing with a rubber boot to prevent dust and other contaminants from getting in where the two sheathed wire harnesses exit the box. You’ll notice that there are eight 30-amp relays (and eight 30-amp fuses to match), even though there are only six switches available. This is to double up on power if you are running an accessory with a single switch that requires more than 30 amps (for example, a 45-amp light setup).
A 200-amp fuse has its own enclosure on the side of the fuse and relay center and offers protection from too large a spike heading between the battery and the relay center, if something goes wrong.
The Trail Rocker kit comes with detailed instructions, but after removing the negative battery lead and a few zip ties and clips, the relay center should bolt on near the battery using the firewall stud meant for the battery tray (it will not interfere with the battery tray). Dirty Parts also removed the engine cover for easier access.
Having a main control center and fuse box would be the most ideal situation, but there isn’t a lot of room under the hood, so fabing and wiring it up on your own might prove difficult. So when the guys at Painless Performance saw the new Wrangler, they started tinkering to see what they could do about adding multiple accessories all in one unit, the Trail Rocker for JK Wranglers was born.
Dirty Parts ran the wire harnesses along the top of the firewall but waited to tighten the zip ties until all wires were connected with everything in place. While the wire bundle may seem overwhelming in size, you’ll end up cutting of a lot of excess wire from that bundle as you hook them up to each accessory. Like all Painless Performance products, each wire is labeled, making it easy to know which switch you’re hooking up to each accessory. The harness with the connector on the end will go through the firewall and hook up to the switch panel
The Trail Rocker switch panel comes pre-wired with a plug-n-play harness that just needs to be plugged into the connector that is fed through the firewall.
The only factory piece of interior you’ll have to remove is the panel directly in front of the auto shifter (unfortunately, the Trail Rocker kits are designed for automatic JK Wranglers, only). After shifting the vehicle into a drive gear (with the Wrangler off, of course), you’ll have enough room to pop out the panel.
With a central fuse and relay center that bolts just over the battery, the Trail Rocker kit feeds one single harness into the cabin that hooks up to a direct-fit replacement interior panel that is adorned with five toggle switches that can control six accessories. Each switch feeds power through a 30-amp fuse and relay that can power most DC-powered auto accessories. Should more power be needed, Painless Performance added two extra fuses and relays that can be doubled up to give a maximum fused link of 60 amps on one toggle switch.
The Trail Rocker switch panel should be a direct-fit replacement panel, only with five switches that can power six accessories (the end switch is a double-throw switch that can power two accessories, but not at the same time). We see the right-end toggle switch being useful for something like a dual fuel pump setup, where one is a backup pump.
Dirty Parts ran wires to the J.W. Speaker LED front bumper lights, the overhead Pro Comp lightbar, and to a winch solenoid. As we add more accessories, we’ll have available switches and positive feeds to run them with. The unused switched power wires were bundled, taped on the ends for safety, and tucked into the engine compartment until it’s time to hook them up. With everything hooked up, all zip ties were tightened, locking the harnesses firmly into place but with enough slack to account for off-road vibrations body/frame movement.
firewall. If you find it too difficult to pass the plastic connector through, you could carefully remove The switch panel harness with the connector was run through the pass-through hole in the the wired pins with a small screwdriver and then re-add the pins into the plastic connector once the harness is through the firewall.
We enlisted Dirty Parts in Los Angeles, California, to take care of the install since they specialize in wiring up off-road accessories. With no previous Tail Rocker installation experience, they had most of the kit done within a couple hours. Total installation time will vary, depending on where you need to run power wires to feed your accessories. We chose to have our Trail Rocker’s power available full time, which meant hooking straight to the battery instead of a switched ignition lead behind the dash. After Dirty Parts was done with the installation, we had a set of toggle switches (one of them a double-throw) in a centralized, easy-to-access control center that eliminated a lot of wiring harnesses and relays that would otherwise be bolted under the dash and hood.
If everything was done right, a correctly installed Trail Rocker relay center should mount with just enough room to add the engine cover back on and still fully access the battery.
You can run a Trail Rocker in a JK either switched (so it only turns on with the ignition), or full time by hooking the switched wire straight to the battery (or an always-on wire). We chose to have Dirty Parts hook up the Trail Rocker straight to the battery so we can operate accessories even if the Wrangler is off.
The Pro Comp overhead LED lightbar uses the most power of our three accessories but still consumes less than 30 amps. If we stacked LED lightbars on the roof, we could have doubled up relays and fuses for a 60-amp maximum switch.
When a toggle switch is engaged, the white lens will illuminate—something hard not to notice, even in the daytime.
