1995 Roadtrek Mysterious Switch

[MechaJubei]

Hi all,

I purchased a 1995 Roadtrek Versatile and on the dash, to the right of the steering column, is a blue switch (see pic) that I can't figure out what it does. Has anyone seen something like this installed? I looked through the manuals (it actually came with them!) and could find anything. It does have a generator so I wasn't sure if it was a battery disconnect switch for the house battery of something like that. It doesn't seem to affect lights or anything.

Any ideas?

Thanks in advance!

[markopolo]

It's very neatly installed & doesn't appear to have had much use. I'm guessing it is lit when on & that would serve as a reminder to not leave it on.

Does your RT have lights in the outside storage compartment(s)? If so, do they work? If they don't then maybe the mystery switch needs to be on for them to work.

Second guess would be that it might be used to power the van radio when the key is off.

[avanti]

Vans from that era often had aftermarket fog lights installed by the upfitter.

The other possibility is a "boost" switch to help start the engine using the coach battery. They are usually momentary, though.

[mkguitar]

4 screws to find out what's behind there- see if something added or spliced into factory wiring harness


mike

[rowiebowie]

That's the switch for the Flux-Capacitor. Whatever you do, don't turn it on until you reach 88 miles per hour.

[MechaJubei]

Originally Posted by markopolo

It's very neatly installed & doesn't appear to have had much use. I'm guessing it is lit when on & that would serve as a reminder to not leave it on.

Does your RT have lights in the outside storage compartment(s)? If so, do they work? If they don't then maybe the mystery switch needs to be on for them to work.

Second guess would be that it might be used to power the van radio when the key is off.

Unfortunately it doesn't light up, so I guess I don't even know when/if it's on or off.

No lights in the storage compartment (although that would be nice!) but I'll check about the radio thing. I have a custom deck in there with Navigation though, so it's not stock anymore.

[MechaJubei]

Originally Posted by avanti

Vans from that era often had aftermarket fog lights installed by the upfitter.

The other possibility is a "boost" switch to help start the engine using the coach battery. They are usually momentary, though.

Fog lights are on my list of things to add, but it doesn't look like it has any on it now.

The "boost" idea sounds great, especially if I drain the main battery somehow. Never heard of that before but I'll investigate!

[MechaJubei]

Originally Posted by mkguitar

4 screws to find out what's behind there- see if something added or spliced into factory wiring harness


mike

Ya, you're probably right and that's what I'll end up having to do. I just didn't want to take anything apart before asking, since maybe it was a normal switch that somebody knew about. I'll probably end up taking it apart today because the mystery is driving me crazy!

[GallenH]

I once thought about a switch that would change the radio from operating on the chassis battery to operating on the house battery. Does that capability exist on most current RVs? Would be easy to test if the mystery switch had that function.

[markopolo]

I had an Intellitec Radio Switch Control in a Class A & probably the same in a Class C. Both had a radio switch on the dash.

[avanti]

Originally Posted by GallenH

I once thought about a switch that would change the radio from operating on the chassis battery to operating on the house battery. Does that capability exist on most current RVs? Would be easy to test if the mystery switch had that function.

I have never seen this done in a B-van, and it isn't as easy as it sounds. There are several issues: There is both continuous and switched power. Indeed, Sprinters (at least) don't have any switched power at all, and are controlled completely by the CANbus. The CANbus itself might create voltage-reference issues (not sure). An ECU may well throw a code if it doesn't see the radio on the bus. You might confuse theft-prevention features, which are also CANbus-related in modern vehicles. I.e., the radio might lock out if it can't get the VIN from the bus. And, you also have to worry about external devices that are powered and/or controlled through the head uint, such as powered antennas or subwoofer amps.

I went down this path once, and quickly concluded that it was a science project. Might be easier with aftermarket head units. OEM radios are a challenge.

[BigBee]

I have a 1997 RT and a similar switch on my dash, also to the right of steering, also appears to do absolutely nothing, and also has power running to it. It lights up when the engine is on and the switch in my van is red, rather than blue. I've tested and tried to determine what its for and can also find no reference or documentation explaining its purpose. It's a mystery. I once told a cranky co-pilot that it was the "EJECT" button and that, perhaps, he might wish to button his lips. Gave us something to laugh about and calmed the cranky down a good bit, so all's well that ends well.

[inforiculturist]

As another said, you will have to trace the wiring. FWIW, I inherited 2 mystery switches when I purchased my 95D190P in Feb 2019. These are all labeled now.

One was on the top right of the steering column: for the radio - either totally off (center), or house battery or engine battery (although the memory wiring was always on). The other one was on the underside of the steering column, and was a momentary switch that enabled a solenoid that allowed jump-starting the vehicle battery from the house battery if needed. So far unneeded but when that happens I'll likely be thankful it's there.

I do need to give points to rowiebowie for his flux-capacitor/88 mph reference. Certainly made me chuckle. My next class-B will be a transformer Delorean.