What is it?

[epretot]

Ok...since you guys let me down in my time of need, I took it upon myself to try to figure it out.

This tube of course comes through the wall from the engine compartment (see pic).

So, I poked my head into the area I thought it may be coming from.

Well...I have a pretty big head and got it stuck. Now when I say I got it stuck, I don't mean stuck-stuck.

Basically, it was just wedged in there tightly.  Not a big deal. But I shave my head about 9 months a year. So you can imagine it wasn't real fun pulling it out. No hair as a buffer from the rust and grime and bolts and wire ties, etc.

Anyway, this could have all been avoided...

[dtcerrato]

Sorry to hear of your misfortune. I would like to have responded but don't know much of MCI as we are a GMC bus owner. Glad everything came out alright - literally!

[chessie4905]

drain tube from ping tank or from aircleaner for rain water drain?

[richard5933]

That tube may come from the engine compartment, but does it originate from there?

Perhaps it passes through the engine compartment but starts somewhere else, like a rooftop a/c unit where it served as a condensate drain.

Most of the OEM drains I've seen have been either black rubber or copper lines. Don't think I've seen lots of clear vinyl tubing being used from the factory on a vintage bus.

[Jim Blackwood]

Something to do with the now removed lavatory? That'd be my best guess in which case it would be unimportant.

Jim

[chessie4905]

just rip it out and see what happens.

[sledhead]

my MCI had a air line that went up into the crapper that I had to cap off but I can't remember what it was for

dave

[buswarrior]

Unlike social media, here on the forums, people are better at keeping silent when they don't know.

Do you really want half assed answers in the last places there is sanity?

Happy coaching!
Buswarrior

[epretot]

The newest episode of "what is it"?

And why do I want to flip it? It even has one of those red covers that should make you think twice. Just like in the movies

This is in the rear jbox

[epretot]

Here is the pic

[Iceni John]

Get one of those cheapo Harbor Fright wire tracers, then you'll know exactly where it goes and what it does without any drama or rude surprises!   The HF one I have isn't the world's best tracer, but for the occasional few times I use it it's OK.

John

[luvrbus]

If I remember correctly that is the fan clutch test switch 

[epretot]

If I remember correctly that is the fan clutch test switch

The j box is labeled. That was an option although the diagram didn't match exactly. Left me wondering...

[Jim Blackwood]

Oh, definitely flip it. How can you not?

Jim

[lhwood]

Here is the pic

According to the wiring diagrams, if you have a push-button ignition, that switch functions in the same way as the "run" switch does up front, enabling you to start/run the engine from the rear without flipping the "run" switch up front.  If you have a keyed ignition, then there appears to be no use for said, pictured, switch.

Our '99 DL3 has this switch but also keyed ignition so it doesn't do anything.  Was hoping it enabled the flux capacitors or something similar, but no luck.

Happy bussing!