I removed RTS wheelchair lift while it was out, and now bus won't budge

[Kevin Warnock]

Hello,

I did a stupid thing today. I removed the wheelchair lift from the back doorway of my 1994 TMC 80286 Series 50 "RTS" bus. To get at the bolts more easily, I deployed the lift, and raised it to the top position, so the platform was level with the interior bus floor. I then fully removed the steps while in this position. I had to cut six wires and disconnect one hydraulic line to the steps to accomplish this.

Now, the green rear door light remains lit even with the rear door closed, and the bus won't move, because the bus thinks the back door is open and/or thinks the wheelchair lift is deployed.

I was able to move the bus only after removing the door/brake interlock relay from the console to the right of the driver's seat. The rear door light stays lit, and the red 'door open' light is still illuminated on the dashboard, but I can drive the bus normally. I needed to move the bus to its storage spot overnight, so I had to do something.

I realize now I should have stowed the lift before removing it. But now what do I do? I had to sawzall through some parts, so the lift can't be reinstalled. I did reconnect the electrical wires I cut, but that didn't help. I also placed small magnets on all the magnetic switch sensors I could find, about 4 of them. I had the stair tread folded as if the lift was stored, and that sensor was next to its companion magnet. I used Radio Shack magnets for the other four. I don't know if they are strong enough or do the same thing as the OEM magnets. There are three wires going into each of the magnetic sensors, and when I put an ohm meter on them, I could not get them to act as switches, no matter which terminals I conected my meter leads to. I never got full continuity... the meter needle only went over half way, not full to the right like if I touch the multimeter leeds together. The needle didn't move when I got the magnet near the sensor, so I don't know if these are on/off switches, or something more complex.

Does the 'computer' control panel for the lift still think the lift is deployed? Maybe I need to reboot it by cutting power to the bus entirely?

What I want to do is take out the rest of the lift mechanism, and attach a remote control transmitter to the rear door so I can open and close it with a keychain transmitter, like used on automobiles to unlock and lock the doors. To do this, I need access to a switch point where a simple switch opens and closes the door, without anyone having to touch the door push bar from inside, which I plan to remove. The current 'on/off' switch for the lift works this way now... when I turn on the lift, the door opens (without touching the interior door push bar), and when I turn off the lift, the door closes automatically. I could just leave the brake/door interlock relay out, and tie my radio switch into the existing lift switch, and be done. But this is messy, as I still have a lot of the lift installed... the left and right 'trolley' mechanisms that actually made the stairs go up and down. I want all that out of the bus, but still want the radio controlled rear door, which will be the only entry and exit for the bus, besides the windows, which I am leaving in place, except for one.

I feel bad for making such a mess of things, and I hope someone can help me with this. Thank you very much.

Thanks,

Kevin
San Francisco, CA

[mak]

I would get a wiring diagram from the manufacture and find out which wires need to be removed or bypassed . On the larger MCI 102 A buses it was just one wire that indicated the door/lift was opened or closed? Anyway, a wiring diagram would go a long way. Might be able to get it on line or call the manufacture.
good luck

[Hartley]

On the older RTS buses all you had to do was pull the brake interlock relay and disconnect the whole
harness from the chair lift control box and all would default to non-chair equipped. The same applied
to the older FLX Metro 870's with the Lift-U or similar package.

I don't know if that was changed later however.

The brake interlock can be disabled on most by pulling the relay, I had to move a Flyer and one of my Flx Metros with
the ramp extended and that was all I needed to remove.

Oh.. You may want to rethink the idea of only having the rear door. It limits your escape routes in case of getting
t-boned or hung up on something on the side. Also the existing door system is probably air operated and making that
remote controlled may mess with the whole door operation system besides not having air pressure ( gauranteed ) to open and close. It can be done but remember the split doors can be a major pain if you have them.

[Don4107]

I too think you need a way to open the door/s that works without air or power.  For safety and aggravation reasons.  Dead batteries will happen. Parts will fail.

[Kevin Warnock]

Hello,

All but one of the side windows will continue to function as emergency exits, and they can be opened in 1 second and are big. Plus, I will leave the roof exits untouched. Finally, I will leave the emergency air release valve in place by the rear door, so the door can be opened without air or power. I will also leave the front door in place, but will seal it with caulk or foam, and in an emergency, that door could probably be pushed open. My objection to the front door is the high wind noise. I don't want to put in an R&M door because that changes the outside look of the bus, which I am trying to keep stock.

Thanks,

Kevin

[Dallas]

Kevin,

The GMC RTS Manual, C-8725 has a complete Wheel chair lift maintenance  section in it for the 80206.
It runs about 56 pages, plus probably schematic drawings.

If you don't have one, I do and might be persuaded to scan whatever parts you need.

IHTH
Dallas

[Kevin Warnock]

I solved the problem. I don't know when or how it happened, but the door closed limit switch metal prong that is depressed by the door mechanism when the door is closed had snapped off. Thus, even when the door is closed, the limit switch was not engaged, thus the bus wouldn't move. As soon as I manually press that limit switch, you hear a rush of air and the red dash light saying the door is opened goes out, and the accelerator pedal resumes functionality. Thanks for everyone's help. In particular, someone on the Yahoo RTS group told me how to hook a wireless remote to the rear door as I had imagined.

Does anyone have any recommendations for quality aftermarket key fob style automotive transmitter/receiver systems? Note that I plan to have a conventional residential house door inside the rear door as well. That door will have normal weather stripping, and will be the main deterant for illegal entry, as I don't plan to make a mechanical lock for the actual bus door. When the air pressure is gone, say when the bus is in storage, someone could pull the doors open. But then they will be presented with the 'real door' that I'll get from Lowes or Home Depot, which will swing out. This way I have something that looks residential inside the bus, and get near total sealing from the elements and wind noise. Now I need a way to trigger the automatic opening and closing of the bus doors when the residential door is opened and closed. Any ideas?

Kevin
San Francisco, CA

[Busted Knuckle]

Now I need a way to trigger the automatic opening and closing of the bus doors when the residential door is opened and closed. Any ideas?
Kevin
San Francisco, CA

How about a switch such as the one that broke? It'll do the same thing, all ya gotta do is wire it like ya want it! BK 

[Hartley]

Over the TOP.....

A House door in a bus...?? OK, whatever floats your boat...

[Sammy]

There should be a "door master switch" that you can shut off the interlock. It should be behind the door on the lower front dash area, on the curbside - as soon as you enter the stepwell,on your right. The fire extinguisher used to be mounted in the same area too.
You should also have a momentary switch on the L/side dash - override for brake interlock, might be on the r/side of the drivers wrap around console.
Hold the switch and you should be able to move the bus. The Vapor VCM probably sees the w/c lift as deployed,and is applying the brake interlock. Try unplugging the VCM (above the rear door baseplate) also.
Sammy