chassis power to Fusion

[don000]

Can anyone tell me whether the yellow wire running diagonally above the accelerator pedal on my 2017 Lounge EXT is the chassis power connection for the Fusion ?

The wiring diagram at page 9-28 of the manual indicates yellow wires for the +12V coach and ignition signal connections to the Fusion, but the ends of this wire run deep into the dash and console, and removing the plastic cover panels to try to find the terminations is a significant challenge in itself.

I'm trying to install a switch into whatever wire feeds power from the chassis battery into the Fusion, so that I don't again end up with a dead chassis battery after parking for two or three days.

Any help would be greatly appreciated.

[hmason72]

While I cannot help with your question about the wire, I did ask Jon at the factory about this. He told me originally the FUSION was wired to the house batteries, but "they" changed that at some point. Not sure why. He mentioned that the repair facility there at the factory location had done a number of mods for people to put the power source to the house batteries so the battery cut off switch could control that power drain.

[FlyFishinRVr]

Originally Posted by don000

Can anyone tell me whether the yellow wire running diagonally above the accelerator pedal on my 2017 Lounge EXT is the chassis power connection for the Fusion ?

The wiring diagram at page 9-28 of the manual indicates yellow wires for the +12V coach and ignition signal connections to the Fusion, but the ends of this wire run deep into the dash and console, and removing the plastic cover panels to try to find the terminations is a significant challenge in itself.

I'm trying to install a switch into whatever wire feeds power from the chassis battery into the Fusion, so that I don't again end up with a dead chassis battery after parking for two or three days.

Any help would be greatly appreciated.

I'll try to test this in the coming days. Right now the temps are too high (supposed to be 102*F today) and my coach is an oven inside. I know the wire you're referring to and I have a multimeter with a current clamp so I'll put that on it and power the Fusion on/off a few times. I should be able to tell pretty quickly if that's the one providing the power. If it is, it should be an easy mod to put a switch in one of the blank spots on the dash, maybe with a LED indicator to tell when the unit it on.

[don000]

hmason72 and FlyFishinRVr, you guys are great.

Probably this change was implemented for a few months' production before Airstream realized that it was ill-conceived. My 2017 Lounge EXT was built 8/30 to 9/1/2016.

A switch in the connection to chassis power would preserve the advantages that motivated the change, while allowing control over its downside. I purchased one of these: http://www.ebay.com/itm/NCV3-Sprinte.../142215633733; it fits perfectly in any of the many blank slots to the left of the ignition.

Edit: Not sure that the link to eBay works. Just Google: "NCV3 Sprinter Dash switch adapter with K1 Otto Switch".

[FlyFishinRVr]

Originally Posted by hmason72

While I cannot help with your question about the wire, I did ask Jon at the factory about this. He told me originally the FUSION was wired to the house batteries, but "they" changed that at some point. Not sure why. He mentioned that the repair facility there at the factory location had done a number of mods for people to put the power source to the house batteries so the battery cut off switch could control that power drain.

From the schematics, it looks like the way to do this is to remove the radio power from the existing CB5 connection point (these are type 2 reset-able breakers, meaning to reset them you have to perform a power cycle, so if one of these breakers ever tripped, you'd have to disconnect the house batteries then reconnect them....stupid, but RVIA mandated.....ugh) and reconnect it to position 13, 14, or 15 of the 12v distribution panel which is just to the right of the 120v breakers under the driver's side jump seat (these positions are listed as "unused" in the schematic, so stick a 15A fuse in which ever position you decide to use and you're good to go). This distribution panel is powered through the new, secondary house main disconnect switch (this used to be the "kludge" SB164 solenoid that you may have read about) and will be totally isolated when the Main Disconnect switch by the entrance is turned off (red light off). This is a relatively quick and easy fix....remove a wire from one spot, move it about a foot to another spot, and add a fuse.

But....(there's always a "but" right?), if you do this, you won't be able to run the radio unless the house power is on (i.e. switching on the ignition won't turn it on any more). Personally, I don't want mine set up this way. I prefer to be able to isolate the power to the Fusion when my coach isn't being used, but have it operate as it does today while it is in use. That means putting a switch in the dash like Don is talking about, and just remembering to turn it on any time I want to use the Fusion, and remembering to turn it off again when I park the coach for a few days/weeks. It's a bit more involved than the first method, but I think it's more flexible in how it operates.

[don000]

Agree, was thinking the same thing. With the switch right next to the ignition key, it should be easy to remember.

[FlyFishinRVr]

Originally Posted by don000

A switch in the connection to chassis power would preserve the advantages that motivated the change, while allowing control over its downside. I purchased one of these: http://www.ebay.com/itm/NCV3-Sprinte.../142215633733; it fits perfectly in any of the many blank slots to the left of the ignition.

Edit: Not sure that the link to eBay works. Just Google: "NCV3 Sprinter Dash switch adapter with K1 Otto Switch".

While Hein's adapter allows the switch to fit in our dash (he's active on SprinterSource and is the seller on Ebay as ImpactProducts which sells the adapter and switches), the switch itself is not appropriate for this application. He even states that his switches should be used with a relay. To avoid that, you really need a switch that can handle 15A going through it....

[don000]

Originally Posted by FlyFishinRVr

While Hein's adapter allows the switch to fit in our dash (he's active on SprinterSource and is the seller on Ebay as ImpactProducts which sells the adapter and switches), the switch itself is not appropriate for this application. He even states that his switches should be used with a relay. To avoid that, you really need a switch that can handle 15A going through it....

Hard to imagine that this switch is not adequate for the small amount of current feeding the Fusion unit (you guessed 500mA on another thread).

[FlyFishinRVr]

Originally Posted by don000

Hard to imagine that this switch is not adequate for the small amount of current feeding the Fusion unit (you guessed 500mA on another thread).

That's my guess for what I call "sleep 2" (screen off, power off, sitting waiting for a human to press the touch panel). The Fusion can pull over 10A when fully on and crankin', so you need a switch that can handle that because the power is running THROUGH the switch.

[tk.1217]

I am having trouble attaching the instructions I received from Jon at Airstream for the proper wiring information for the Fusion Radio to make sure it does not drain down your chassis battery. PM me and I can send it to you. It has pictures and is quite clear for the novice.

[don000]

tk.1217, PM sent. Very kind of you.

FlyFishingRVr, from the wiring diagram and use of the vehicle my impression is that the connection to chassis power just provides maintenance power to the Fusion, in some fashion. I don't recall that the unit is fully operational unless the coach power is on.

In any case, the rating on the Otto K1 switch that I purchased seems to be at least 10A, maybe 16A; data sheet is attached.

[FlyFishinRVr]

Originally Posted by don000

FlyFishingRVr, from the wiring diagram and use of the vehicle my impression is that the connection to chassis power just provides maintenance power to the Fusion, in some fashion. I don't recall that the unit is fully operational unless the coach power is on.

In any case, the rating on the Otto K1 switch that I purchased seems to be at least 10A, maybe 16A; data sheet is attached.

I can turn the ignition on in my coach and the Fusion turns on even though the house power is off (main disconnect off, LED is out).

My only concern with this whole "where does the Fusion get its power from" is why is my chassis battery getting hammered while the coach is just sitting doing nothing. The only thing I can come up with is it's due to the Fusion drawing a fair bit of power from the chassis even while it's "off". Once I get around to it, I intend to figure it out.

If you believe the schematics, there should be zero draw on the chassis from the Fusion. It should ONLY pull from the house. If that's really the case (I don't think it is, but we'll soon see), then something else is drawing my chassis battery down....hard. Without my solar setup, my chassis battery would be dead in less than a week. I don't believe that's how Mercedes designed it, so it must be something Airstream added. Again, I intend to figure it out....it's the engineer in me wanting to know "why".....

[don000]

Correcting my earlier remarks, the Fusion will indeed run in my unit with the ignition on but the coach power off, just like FlyFishinRVr's unit.

The audio/video schematic in my 2017 owners manual, if I'm reading it correctly, shows two connections from the chassis to the Fusion unit: 12V power coming from the Mercedes radio harness connector, and an ignition signal. Separately, there is a 12V supply from the coach.

On the Fusion connection harness (wherever that is - I get stalled trying to disassemble the dash), 12V power from the chassis is at terminal 20, while 12V power from the coach is at terminal 11. The ignition trigger is at terminal 21.

I'd imagine that the chassis power drain is through the blue/white wire at terminal 20. I just don't know how to get to that wire to install my switch.

[FlyFishinRVr]

Originally Posted by don000

Correcting my earlier remarks, the Fusion will indeed run in my unit with the ignition on but the coach power off, just like FlyFishinRVr's unit.

The audio/video schematic in my 2017 owners manual, if I'm reading it correctly, shows two connections from the chassis to the Fusion unit: 12V power coming from the Mercedes radio harness connector, and an ignition signal. Separately, there is a 12V supply from the coach.

On the Fusion connection harness (wherever that is - I get stalled trying to disassemble the dash), 12V power from the chassis is at terminal 20, while 12V power from the coach is at terminal 11. The ignition trigger is at terminal 21.

I'd imagine that the chassis power drain is through the blue/white wire at terminal 20. I just don't know how to get to that wire to install my switch.

It looks to me like the blue/white wire (pin 20) is the "on" signal for the subwoofer. You'll see it goes to pin 5 of the sub, labeled as ENA (I assume that's short for Enable, since the sub already has power coming in at pin 4).

The only power I see coming into the radio harness is on pin 11, which will be a large yellow wire that butts to a large red wire, and it's labeled as "Coach +12v Batt".

[don000]

Originally Posted by FlyFishinRVr

It looks to me like the blue/white wire (pin 20) is the "on" signal for the subwoofer. You'll see it goes to pin 5 of the sub, labeled as ENA (I assume that's short for Enable, since the sub already has power coming in at pin 4).

The only power I see coming into the radio harness is on pin 11, which will be a large yellow wire that butts to a large red wire, and it's labeled as "Coach +12v Batt".

Right you are. I need a better magnifier.

Could it be possible that the Fusion unit draws chassis power through pin 21, the ignition signal ? In addition to a connection that seems dedicated to the ignition signal, there is a second fused connection to pin A4 on the Airstream to Mercedes interface, labeled "K130 BAT. DIR." and the wire is indicated to be yellow. I recall now that this is why I suspected the yellow wire in the photo attached to my first post in this thread.

[FlyFishinRVr]

Originally Posted by don000

Right you are. I need a better magnifier.

Could it be possible that the Fusion unit draws chassis power through pin 21, the ignition signal ? In addition to a connection that seems dedicated to the ignition signal, there is a second fused connection to pin A4 on the Airstream to Mercedes interface, labeled "K130 BAT. DIR." and the wire is indicated to be yellow. I recall now that this is why I suspected the yellow wire in the photo attached to my first post in this thread.

I'm a bit confused by that wire as well. It has a 5A inline fuse, which seems odd for an ignition signal wire. Signal wires should pull mA, not Amps. Yet if it was supplying power, the 5A fuse is too low because the Fusion can pull over twice that. Plus, why provide power through the ignition? My guess is this is something Mercedes required as a way to protect the ignition circuit in the event something goes wrong on the Fusion side of things.

[tk.1217]

I am having trouble attaching the instructions I received from Jon at Airstream for the proper wiring information for the Fusion Radio to make sure it does not drain down your chassis battery. PM me and I can send it to you. It has pictures and is quite clear for the novice.

[don000]

tk.1217 very kindly forwarded to me via e-mail the instructions that he received from Airstream. To upload them here I've had to convert the document to PDF, as the forum limits Word attachments to just 100 KB. Metadata in the Word document indicates that it was authored by Jon D. Puckett, an owner relations representative at Airstream.

I've not yet attempted the repair, but my impression from the instructions is that the connections from the Fusion unit to chassis and coach power were erroneously reversed during assembly on our affected units. This was probably because the assembler spliced like-colored wires, while the audio/video schematic in the owner's manual shows that the red should splice to yellow, etc.

The photos do not easily correlate to the schematic, so I can't predict how the repair will affect the functionality of the Fusion, in particular whether the radio will operate with ignition on but coach power off. Will report back - maybe the switch that we've been discussing will not be necessary.

[tk.1217]

I can verify that the fix will make everything work power wise like normal. Ignition will turn on/off radio without coach batteries on. One thing to note is that there is still a small amount of power to radio because I can put in a destination and it will remember it when I turn off ignition and back end. This fix will alleviate running down the chassis battery.

[FlyFishinRVr]

Originally Posted by don000

tk.1217 very kindly forwarded to me via e-mail the instructions that he received from Airstream. To upload them here I've had to convert the document to PDF, as the forum limits Word attachments to just 100 KB. Metadata in the Word document indicates that it was authored by Jon D. Puckett, an owner relations representative at Airstream.

I've not yet attempted the repair, but my impression from the instructions is that the connections from the Fusion unit to chassis and coach power were erroneously reversed during assembly on our affected units. This was probably because the assembler spliced like-colored wires, while the audio/video schematic in the owner's manual shows that the red should splice to yellow, etc.

The photos do not easily correlate to the schematic, so I can't predict how the repair will affect the functionality of the Fusion, in particular whether the radio will operate with ignition on but coach power off. Will report back - maybe the switch that we've been discussing will not be necessary.

Thank you both for providing this information.

Re. relating this to the schematic, I'm not sure the actual wiring EVER was correctly depicted in the schematic and that's been part of the problem. If you look at the schematic on page 9-27 where it shows that connector, you will see there is no place where a red wire is next to a yellow wire, yet you can plainly see this in the photo.

I agree, without more detail from Jon, we have no way of knowing exactly what this fix addresses. Is it just where the Fusion draws its power (chassis vs. coach), or is it also the seemingly large current draw while "off"? tk.1217, can you reach out to Jon and ask?