2003 E450 Quigley - Wheeled Coach - Where to start with the electrical - HELP!!


New member
Hi there,

So I have just purchased a low mileage E450 Quigley and ready to start work. The initial plan is to do a full gut, reroute the overhead electrical (rip out anything unneccesary) and raise the roof. I am looking for as much input, links to resources in tackling the electrics... not going to lie, it looks to be a daunting task. I know how to use a multimeter, but am far from an electrician. From reading I need to be careful separating the house circuit form the vehicle. A few questions in addition to general resources and advice:

1. The cab switch panel. Are people generally deleting this altogether? If Yes or No, please provide some detail on how to streamline it.

Cab switches.jpg

2. Notice this ford contorller. Is this for managing the current house electrical system. Can anyone link me to more information on it?

3. There is a 4wd shifter, however there is this 4x4 button (quigley conversion). Is this for locking the hubs? the hubs appear to have black manual locks on them, similar to warn
4wd switch.jpg

4. Where do I start with the panel, what to keep, what to delete? also any good dummie guides to ambulance electrics.

Pic of the rig for reference. Thanks in advance. I am here to learn, send me everything.:alien:


New member
I pulled the console and added the switches I wanted behind the seat. They controll a relay board, and I mirrored the functionality of the console. The switches just short the control wires to 12v.

View attachment 611861

Thats a tidy solution. Any recommendations on resources for someone newer to electrical systems, primarily vans. Have you any wheeled coach specific schematics? Any help is much appreciated.


I dont know anything about wheeled coach, but I would spend some time on it and take pictures of everything.

Try to figure out how it all works before pulling it apart. I had a master toggle that controlled a master "power disconnect switch" if I had missed that nothing would have worked.


New member
Here is a link to a discussion on the Ford Auxilliary Idle Control module:

I also attached the manual if you want to reprogram it.

Can be used to put engine in fast idle mode or “charge protect mode” which is used in some ambulances to idle truck faster to deliver extra amps for lights and sirens if needed when at a scene.



New member
I just finished supplementing the wiring / redoing some parts on a Wheeled Coach build of the same era. I got schematics for the truck from Wheeled Coach which helped immensely. I at this point feel pretty confident I can answer most questions about how those trucks are wired though.

My overall strategy was to keep the truck wiring / exterior lights on the WC-built board, and then add my own "house" system where my batteries/solar/inverter/lights/fridge/heater/etc are wired. This lets me keep most of WC's wiring stock, with some small modifications to modernize/supplement it, and lets me have free reign for my design. I used a DC-DC charge controller to bridge the systems, since my truck has dual alternators this lets me charge my house batteries when the truck is running.

1 - did not delete, but modified. I added some switches and dropped ones I didn't need (siren, airhorn, etc.) I've reused the existing wiring here for the most part. Trickiest part was removing / converting the three-way switches where the front / rear both had a switch (i.e. interior lights.). Happy to give more detail/go into specifics.

2 - I believe the AIC is setup by WC out of the box to maintain 14.2V from alternators when in Park with P-Brake engaged.

3 - No idea, I have a RWD e450.

If you want to get into details I can probably do better over the phone. If that'd help let me know and I can PM you my number.

(edit to supplement -- I found build sheets in the truck, zip tied to the wiring harness near the distribution panel and inside of the center console. These had the wire codes (these are the numbers like OPT357 or W21 printed on the cables) for each circuit breaker, switch, etc. The wire codes on their own aren't completely meaningless, (BRAKE and IGN, for instance, are pretty obvious) but will make a lot more sense with the truck schematics.)


With #3, pretty sure that’s just an indicator light to show when 4x4 is engaged, not an on/off button. Quigley installed that on all their conversions that I’ve seen. Looks like there is an actual switch underneath that, but it’s likely for something else. Not sure how an ambo would be set up, but many Sportsmobiles have a “momentary” button in the same location that overrides the battery isolator for the chassis and coach batteries to allow the house batteries to be used to “jump start” the van if the chassis battery dies.

Sent from my iPhone using Tapatalk


New member
Following along... My new (to me) ambulance is coming home today and has those same switch panels and controllers. I’ve been pondering what to do with it all.


I just cleaned up my Wheeled Coach forward switch panel and added cupholders -- see my build thread. Probably a bit easier for me as my Red Cross ERV started with far fewer switches than your ambulance. I also found a partial wiring schematic zip-tied near the main circuit board. The schematic doesn't explain all of the wiring codes, though.

Following. I am building my 4x4 ambo now. I have a type 1 1996, but just found out the box is a type 3 wheeled coach remount from 1987! I am thinking my electrical will need to be figured out with time and a test light. As for th 4x4 button, are you sure it's a 4x4 button? I see a 4x4 light then a button that has had a label torn off it below the light? I'd check if they illuminate when operating 4x4 with the shifter