While removing skoolie wiring will be slightly different for varying makes and models of busses, the general process remains the same:
- Go SLOWLY.
- Label EVERYTHING.
- START the bus and check all electrical components after each disconnect.
Tedious? Yup.
Safe and effective? For sure.
You don’t want to be the one desperately posting in a forum, “Please help! I cut some wire last night and now my bus won’t start!”
Like removing the pneumatic stop signs and dealing with the air systems, I worried about doing something stupid and screwing it up. So I worked on removing the wiring strangling my bus one system at a time.
Tools
I found the following tools helpful in removing skoolie wiring.
- Box Cutter Knife: to cut the wrapping (not the insulation) around wire bundles
- Multimeter: For testing circuit continuity and voltage
- Testing Light: For checking for power
Removing School Bus Warning Flashers
I worked on these first because I felt like they were the least likely to be integrated into any system that I would want or need. Plus, the wires were big and visible, so I thought it would be a good “entry level” electrical project.
First, I disconnected the negative (black, not the red) cable from the battery to prevent any shorts. I learned this the hard way, once. I was disconnecting the positive side, once, and fumbled a bit. By getting the positive terminal just close enough to the battery post, the connection arced and welded the wire terminal to the post. When I tried to pull the wire off, I broke the battery post.
There was some swearing, I think.
Anyway, this doesn’t happen when disconnecting the negative side first.
Next, I unplugged the spade connectors from the rear lights. Then, to be safe, (I felt a bit paranoid, I confess) I started the bus and checked all the lights and blinkers.
So far, so good.
Then, I started pulling the wires back toward the front of the bus. This was also was a tedious process. I had to cut the black wrapping around the snake of wires running down the length of the bus to the electrical panel just outside of the driver’s seat.
I worked carefully so as not to slice through any of the wire insulation.
Once I reached the panel, I traced the wires to their termination points. Most of the wires terminated at spade connectors on a yellow flasher panel. One connected to a common ground bolt, and another fed to a power bus bar.
Working around the power bus bar is a royal pain in the you-know-what. About six million wires feed directly behind the bar up into the switches in the driver’s console. So, I had to unbolt the bars to that I could actually trace the wires. Which was still a royal pain.
Removing Skoolie Wiring Console Switches
The wires connect via plugs to switches. I labeled each plug, unplugged the circuit I was working on and traced the wires back to the panel.
The black wires connected to the power bus bar. I labeled the wire on the circuit chart on the door of the panel, then unbolted the power wire from the bus bar.
The larger white wires connected to a common ground bolt, which I undid, removed the wire, then reinstalled the nut on the bolt to preserve the ground connection to other circuits.
The small blue wires from the switches provided power to the little lights on the switches so you can see them at night. They terminated at a different and smaller bus bar that I am guessing provides a lower voltage. Here, I clipped and labeled each individual wire.
Similarly, the small white wires connected to a grounding bus bar for the switch lights. Again, I clipped and labeled them.
Actually pulling the switches from the console also presented a challenge. They’re in there tight! I wanted to re-use them as light switches in the bus, though, so I carefully used a small screwdriver to pry them out without breaking them.
It was an epic victory for my patience.
Check, check and Double-Check
After I disconnected each circuit, I reconnected the battery, started the bus, and checked all the lights and horn.
Once again, everything still worked.
I did a little happy dance.
Removing Skoolie Wiring for Speakers and Ceiling Lights.
Although I plan on reinstalling ceiling lights, (and speakers somewhere…not necessarily on the ceiling) I want to put in LED’s for better battery efficiency. I also want to rewire them so that the controlling switches are in the actual space we want to light up, not on the driver’s console. So I removed all that wiring.
These circuits connected to a wiring harness plug in the electrical panel. Oddly, I thought, the speaker wires connected to a harness that shared wires with the tail-lights and rear blinkers, so I couldn’t just unplug the harness. Instead, I clipped the wires, covered them with tape, and labelled them in case I ever needed to put them back.
Removing Skoolie Heater Wiring
I had removed the two heaters from the cabin of the bus. I left the one next to the driver’s seat and the front one next to the stairwell. I imagine that we will be driving in some cool weather, and will want some heat, and, more importantly, windshield defrost, so I kept them intact.
The wires from the rear heaters and heat pump, however, needed to go. So just like before, I pulled the wires back to the electrical panel.
It was getting a little easier now. I felt a bit more confident and there was less wire in the way. Once again, I traced them back to the electrical panel and cut the wires where they entered a shared wiring harness.
The Great Windshield Wiper Snafu
This time, when I started the bus to check everything, it was raining. So I turned on the wipers to clear the windshield. Why? I don’t know. I wasn’t going anywhere, but I just felt like I needed to wipe that rain away.
Nothing.
Dagnabbit.
Perhaps I had been overzealous in removing skoolie wiring.
I had tested all the lights through the process but had forgotten about the wipers.
So got out my multimeter and checked for power coming into the wiper switch. (I connected the ground clip to a common ground screw on the console and inserted the probe into the power connector on the wiring harness. I set the multimeter to the 20volt setting).
Nothing.
So I traced the wire back to the power bus bar and tested the bus bar.
Nothing. In fact none of the connections on the bar had power.
Then I traced the power source of the bus bar to the output of one of the 2 solenoids. (The output of the solenoid to the left of the panel fed the input to the solenoid on the right.) I connected the multimeter to both the output lug and the incoming line to the control circuit: nothing.
To test the solenoid, I used a wire jumper. I hooked one end to the control switch output of the other solenoid. (I had tested it with the multimeter and it had power) and connected the other end to the control circuit.
Everything powered up and the windshield wipers came on!
Progress.
So, now I had to trace the control circuit. Which proved to be a challenge. I felt like Steve Irwin searching for some rare, exotic animal. “Crikey! Look at that mess of wires in there! That’s where it hides…
I tracked that wire up behind the power bus bars, through the console, under the dashboard, over to the ignition switch…and that’s when I saw it: a fuse panel just to the right of the ignition switch.
I popped off the cover and started checking fuses. And there it was. The culprit was a blown 10 amp fuse. I replaced it and the wipers worked!
Checking the Fan Wiring
After removing most of the unnecessary wiring, I began considering how I would reassemble the console. I had taken out many of the circuits after all, so I didn’t need all the space allotted there. At the same time, building a completely new one might present challenges with curves and odd angles. So, I needed to start putting switches back together and consolidating all the necessary components so that I could start “s’posin'” where everything was going to go.
Part of this process involved hooking up the fan that sits above the dashboard. I don’t plan on running any air conditioning, so this fan will probably come in handy.
I remounted it to the frame above the windshield assuming that it needed to be touching metal to be grounded. But when I flipped the switch nothing happened.
A veteran wire-chaser now, I felt undaunted. I traced the power wires back to the power bus bar, checked it with a test light and discovered that there was no power to that bus bar at all. After a moment of puzzling (not even enough to make my puzzler sore) I remembered that the “Master Heater” switch needed to be on to power that bus bar. So I returned to the driver’s seat, flipped the switch and, voila, working fan! (I do think that I will relocate that power lead to the other bus bar, though, so I don’t have to flip the “Master Heat” switch to get a cool breeze through my hair).
Conclusion
I admit I felt a bit intimidated by removing skoolie wiring at first. However, like anything else, the more time I spent on it, the more skilled and more confident I became. Who’d a thunk? The more you practice the better you get. Revolutionary.
Anyway, I found that taking my time, labeling everything, and checking bus functions after every disconnect got me through the process without rendering the bus non-functional. I’m looking forward to the creative process of putting wiring back in!
For you more visual learners, check it out on youtube!
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