Point Five Ambo Build


Expedition Leader
Mine is a 1993 so I didn't think there would be much difference, but there is at least where the electrical is concerned. Some of the heavy looking cables in that overhead trough is going to the light bar on the rear, and there is one on the front also. It the same kind of system where a big cable full of tiny wires control a bank of circuit breaker protected relays in the light bar itself, to control all of the different functions.

But, what I don't understand yet is why I found orange wires in that trough marked 'Left Turn', etc. when there is the Ford OEM wiring harness running to the rear in the frame for the turn, brake, and backup lights.

I also have strobe lights in my corner marker lights which adds a whole bunch of other cables.


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Pat, I've said it before, and I'll say it again -- I'm mighty glad that my 1999 ambulance was built just prior to the implementation of solid state electronics for all the switching. I see parts for the digital equipment from time to time, and the prices are definitely up there. Even if you have a Horton Intelliplex system, used control panels or relay panels run into the hundreds of dollars. If you need to reprogram the equipment, lottsa luck finding someone who can do it, and if the maker of your buggy is no more, then you are in for a world of hurt because this equipment was proprietary to each manufacturer. A lot of it was built by Weldon, but each manufacturer put their own spin on it.

I have a Medic Master, and they have been gone since 2008 - but my unit uses all conventional switching and relays. I can replace a relay for about $4.00, and a new switch can run as much as $12! Anybody with a newer Medic Master with solid state controls will really run into problems if anything happens to their equipment.

My wiring is a little more cumbersome to work with, but I can at least work with it.

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Expedition Leader
Bob, I hope to get mine back to that state.

It's much older than yours, but it still has PC Switchboards which are proprietary to Wheeled Coach. The components work and the problem is not with them as much as it is with the electrician who threw it all together. Still much better that any RV, but nowhere as neat as it should be or as easy to troubleshoot.


I have circuit boards, except Medic Master bought off-the-shelf relay boards from Wired-Rite Systems. The boards can be triggered by negative or positive switching, and can also be set up for sequential load startup and also load shedding if the battery voltage drops. Wired-Rite sent me PDFs of the manual for the boards.

DSCN4739.jpg DSCN4740.jpg


And since the Medic Master wiring is labeled, I've been tracing wire numbers/tags whenever I open an area and find wiring


Expedition Leader
I've got numbered tape like that also, and I'm thinking of starting a temporary ledger book to keep track of what I identify.
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Expedition Leader
About a week ago I finally got my new Whelen 900 Series Halogen lights installed on each side, but I haven't had time to write it up until now.

Since my ambulance is a 1993 model, it had the much older 97 Series lights on it. According to all the 'experts', the 900s are suppose to be a drop in replacement but they aren't, at least not in my case. The shape of the hole is the main problem and the sloppy work of the person installing them originally, is the other problem.

The 97s use a hole shaped like this:


But the 900s require a hole shaped like this:



I also had a set of chrome bezels cleaned up and ready to install along with the lights, but discovered they would not work without serious modifications due to the close proximity of the four warning lights to the corner extrusions and compartments. The scene/work lights would work fine, but then they wouldn't match, so I just left them off for now.

Basically, these are the steps I used to make them fit:

1. I started by creating a template made out of clear Lexan, so I could see what was going on underneath.


2. Now I could see the alignment of the existing mounting holes in relation to the accurate mounting holes, and the same with the cut out section.



3. Once I had the mounting holes accurately re-drilled, the lights still wouldn’t sit in the holes like they should. The new lights came with nylon inserts to put in the holes for the screws to anchor into.


4. I compared and measured the 900’s (black) with my old 97’s (gray) and the reflector bowl height was the same, but the 900 width was a little smaller, which should have made them easier to fit.



5. The 900’s have 2 nipples on the back of the reflector, one in the top right, and one in the lower left corner, similar to what you see on the halogen automobile headlights for draining. These things stuck out almost 3/8” and looked as if a drain tube could be attached to the lower one.

HPIM1443 - cropped.jpg

6. If I had the 900 pattern cut outs, these nipples would have cleared, but since I wasn’t looking forward to cutting about ¼” all the way around each opening x 8 while standing on a ladder, I chose to just cut the plastic nipples off flush with the reflector. After that, they fit fine.


7. Right now, I’m leaving them open so the light housings can breathe, but if I notice any water in there, that means the seal is leaking and will need to be reseated. If that doesn’t do it, I’ll tape the holes up.
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Expedition Leader
And here is what they look like mounted.

Left side...



Right side...



As I mentioned, these are just stock halogen lights and are not the final product. The lens pattern on these is for warning traffic and not for scene or work lights (no flood pattern), so they won't do the job anyway. The finished product will be LEDs of some sort, primarily because I need the lower current draw since I don't have an engine and alternator to charge the batteries while they are operating as flood lights, possibly for extended periods of time in camp.

Right now, I'm just trying to get the outside closed up and looking decent, with all of the required DOT lighting working so that I can go get it registered and get a tag on it.
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Lookin' good, Pat. You know, there's no reason why you can't keep the halogen scene lights. You can always install some surface mount led lighting for normal use


Expedition Leader
Actually Bob, I considered that since I have four of these Rigid Scene Lights now.



These would be easier to install directly on the wall, rather than making adapter plates like we discussed. And I could pull power either from the third leg in the cables for the Whelen scene lights, or by redirecting the existing corner strobe cables from them to the Rigid lights, since the strobes will not be used.


That way, you could run the halogen and the leds with your Honda generator if you really needed light. The Rigid lights are nice - I may add some as well.


Expedition Leader
Since the halogens basically are aimed out parallel to the ground, they would cover an area that the LEDs won't. Once camp was set up, I normally wouldn't need light that far out so the halogens and generator could be shut down and just use the LEDs.

I think we just solved another problem!

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