Mystery toggle switch on fuel tank

richard5933 · September 14, 2017, 12:24:12 PM

There is an inspection window in the bay next to the fuel tank. In the access port, there is a toggle. Can't find any reference to it in the manual. Anyone know what it does?

Richard

1964 PD4106-2412

Scott & Heather · September 14, 2017, 12:31:52 PM

Richard, was that for a primer pump?

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chessie4905 · September 14, 2017, 12:32:43 PM

Could be for a light or fuel gauge mounted by the tank. Gauge was an option on some models.

richard5933 · September 14, 2017, 01:04:05 PM

Quote from: Scott & Heather on September 14, 2017, 12:31:52 PM
Richard, was that for a primer pump?

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I wish I knew. It appears to have been there for a while. I found it in this position and have left it there until I know what it does.

Richard

gumpy · September 14, 2017, 06:32:22 PM

Quote from: richard5933 on September 14, 2017, 01:04:05 PM
I wish I knew. It appears to have been there for a while. I found it in this position and have left it there until I know what it does.

Richard

Well that's not very adventurous! Chicken!

richard5933 · September 14, 2017, 06:58:55 PM

Quote from: gumpy on September 14, 2017, 06:32:22 PM

Well that's not very adventurous! Chicken!

Chicken? I'm okay with that if it means nothing goes bang on the night...

With my luck it would be the emergency fuel dump switch and I would find 140 gallons of diesel on the driveway.

It's got to be there for something... Just wish I knew what.

If it's a light, then where's the bulb?

Richard

1964 PD4106-2412

eagle19952 · September 14, 2017, 08:24:45 PM

how would you know.
it may be in the off position.
it may be in the on position.

richard5933 · September 15, 2017, 04:10:44 AM

Quote from: eagle19952 on September 14, 2017, 08:24:45 PM
how would you know.
it may be in the off position.
it may be in the on position.

Exactly my point. There is paint over spray on the switch which matches the bay walls. I'm going to guess that if it's not factory then it was done while still in service at Trailways.

That being the case, I'm hoping that someone else has seen such a thing.

Richard

1964 PD4106-2412

chessie4905 · September 15, 2017, 06:26:03 AM

What is that thing directly behind switch? Can you access underside of switch?

DoubleEagle · September 15, 2017, 07:02:17 AM

If it got installed by a previous owner they had to drill the hole somehow and insert the switch from below. Look underneath or feel the switch by reaching in, find the wires and trace them to what they are controlling. It might be for bay door locks or front door release, lights, primer pump, etc.

richard5933 · September 15, 2017, 11:38:37 AM

Quote from: chessie4905 on September 15, 2017, 06:26:03 AM
What is that thing directly behind switch? Can you access underside of switch?

The photo actually posted turned 90 degrees counterclockwise... The two fuel lines (for Webasto) run alongside the left-hand side of the opening.

The thing in the back of the little tunnel and somewhat behind the switch is the inspection window for the fuel tank. It's located in the bulkhead immediately behind the fuel tank, about 2/3 of the way to the back of the tank. I've tried looking from the tank filler door, but there is nothing visible. I might be able to get a scope in there, but all I'd see is the sheet metal that makes the tunnel between the bulkhead and the inspection window.

The bay opposite the fuel tank on this coach still carries the original OTR a/c condenser. It is fully functional, so I don't want to go digging in there.

The switch looks to be original or darned near close to it. I did more the switch but saw no apparent results. I the put it back in the found position. Would sure like to know what this is and if it could be of some use.

From the looks of things in this coach, there are appear to be a few generations of work done. There is of course the factory work. Next I've been able to identify things which were switched out while still in operation as a passenger vehicle. Then there is the generation of things that were done by the conversion shop. Lastly I've got lots of tweaks and modifications done by the previous owner.

By the looks of this switch and the fact that the wiring is not accessible without pulling the tank, I'd have to guess that either it is original or done by the shop at Carolina Trailways. I just called and asked Luke, and he had no idea. If he hasn't seen this, then I'll have to assume that it was done by the Trailways people. Maybe they installed inspection glass into their tanks for times the fuel gauge crapped out?

Or, maybe this is the holding cell where the bus gremlins were sent to live?

Richard

RJ · September 15, 2017, 09:08:33 PM

Richard -

Is that a "momentary on" type switch, or does it click over from one side to the other?

richard5933 · September 16, 2017, 04:22:00 AM

Quote from: RJ on September 15, 2017, 09:08:33 PM
Richard -

Is that a "momentary on" type switch, or does it click over from one side to the other?

Pretty standard on/off toggle switch.

Richard

gumpy · September 16, 2017, 07:34:28 AM

My money is on a starter disconnect. Security feature. Did you try to start the bus when you flipped the switch?

birdarchitect26 · October 03, 2017, 05:58:18 AM

I would say it has something to do with fuel! My money is on an electric fuel pump, maybe a primer pump, possibly hooked to the pick-up. I also bet it doesn't work anymore. I would pick up a rigid inspection camera on Amazon for 10 bucks and play with a new toy!

Maybe a little pump from the AUX tank?

J