Exterior LED lights in op

[Teagonator]

Can anyone tell me when the 4 LED lights on the exterior above the drivers and passenger door on a 2018 Isata 3 are supposed to come on? I would figure they would come on at night when the door is opened but they don't. I haven't driven at night yet but have put the ignition to the ON position to see if they would come on but they didn't. Any help is greatly appreciated.

[Radar224]

When you flip the switch.

We don't have a bunk above the cab so our switch is located right above the driver's seat, between the cabinet doors.

Marinus

[Teagonator]

Thanks for the info. I was so stumped and figured I had a wiring problem. Had no clue what that switch was for as I figured it was something in the interior. I figured those lights would come on at night when the doors are unlocked by remote or manually and not by a switch inside the coach. It would make more sense to me to have them come on automatically when the door is opened or unlocked rather than an interior switch.

[Radar224]

Yes agreed, it would.

[milkman55]

I have never turned mine on in 2 1/2 yrs. It’s a nice concept, but they should come on when the driver and passenger door is opened. I would never think to reach up and flip the switch before I get out of the door.

[Radar224]

Should be an easy modification to do.
The switch and the cab wire are very close together in an accessible area.
I might do that.

Marinus

[Magnatudes]

There's a catch to doing this. The dome light in the cab is chassis battery powered and the LEDs source their power from the coach batteries. Also, the dome light dims. You need to make sure you isolate the two power sources.

[chroniekon]

I use mine as porch lights if we are out and about and returning after dark or setting up camp at night.

[Larry-NC]

Originally Posted by Magnatudes

There's a catch to doing this. The dome light in the cab is chassis battery powered and the LEDs source their power from the coach batteries. Also, the dome light dims. You need to make sure you isolate the two power sources.

Good point. The easiest way to do this is to mount a second switch in the door frame. They are usually a one-terminal switch. When the button is released, that terminal is grounded.

So run a hot wire to the LEDs, and ground the other LED terminal with switches at one or both doors.

[bclemens]

It should be like that....but getting Mercedes to give us any triggers is problematic. Everything is on a CANbus and to prevent people from figuring it out, they keep changing it.

They give you an option for a PSM that is for upfitters. However, it has limited functionality. Just this past week I asked about a trigger for door loCK...so if you unlock the cab it unlocks the coach door. Oh, yeah, that's a whole other option you have to buy on the chassis just to get that trigger.

[Magnatudes]

CANBus throughout without controlled open interface for end-users is BullS#!T. Ultimately, the CANBus controller has to drive a device/output, like a solenoid, relay or dome light. I wired in a voltage sensitive extremely low power electronic relay into the dome light & tied that into the LED switch for the external lights. If the switch is turned on for the external LEDs, they come on when you open a door. The relay is a small circuit board mounted inside the overhead cabinet next to the LED switch.

[bclemens]

Winnebago did something similar when wiring up their aftermarket, RV geared radio to utilize the MB steering wheel controls. Had a device to read the canbus, ended up shutting down the chassis. Not sure what the Canbus did not like...but it went crazy.

IF we, add a light, LED or otherwise to their wiring, it can create a "check engine" or "Tail-light out" indicator. Its amazing how sensitive their stuff is...it makes building on that platform tough...and the newer chassis seems to be even more finicky.

[Magnatudes]

I did get the steering wheel controls working with the XITE. But it's a hokey/limited deal. No issues with the CANBus going nuts though. I agree, that whole monopoly with Mercedes sucks.

[lilbroduck]

Originally Posted by Radar224

When you flip the switch.

We don't have a bunk above the cab so our switch is located right above the driver's seat, between the cabinet doors.

Marinus

Where is said switch when you DO have a cab over bunk?

[Radar224]

I had a close look at it today and found that by going through the wood right above the cab light bulb, you end up in the cabinet that houses the switch for the outside lights. (we have cabinets above the cab)

So to stay completely away from any connections to the Canbus system my plan is to do the following:
I ordered an adjustable photosensitive relay circuit.
The plan is to place the sensor right above the cab bulb and let the light from the bulb trigger the circuit. (the light, not the power to the light)
The relay will be placed in parallel to the actual switch and should trigger when the cab light activates.

Total cost in parts will be around $10 and no circuits will be compromised.

Very simple and quick to install. (In theory this should work :-))

[milkman55]

Originally Posted by Radar224

Very simple and quick to install. (In theory this should work :-))

We will be watching, pictures please.

[Magnatudes]

Originally Posted by Radar224

I ordered an adjustable photosensitive relay circuit.
The plan is to place the sensor right above the cab bulb and let the light from the bulb trigger the circuit. (the light, not the power to the light)
The relay will be placed in parallel to the actual switch and should trigger when the cab light activates.

Total cost in parts will be around $10 and no circuits will be compromised.

Very simple and quick to install. (In theory this should work :-))

Ingenious idea. What is the part number and source for the photosensitive relay?

[bclemens]

This should be fun...just in time for us to get rid of the lights. The new 2019 chassis forced a glass redesign. So that flat area went away....maybe Ill find a new spot if we can get puddle lights to work

[Radar224]

The parts I ordered are on the slow train so it will be a bit before I can try this.

For those that are interested, the item I ordered is similar to:
https://www.amazon.ca/GEREE-Control-...gateway&sr=8-3

There might be better circuits out there.

This is just my guess which hopefully will work.
My search criteria were that it had to be adjustable and the relay has a normally open and normlly close contact on it. This way I should be able to use the closed side of the relay when the sensor senses light.
Tucking the sensor up and away high enough to prevent triggers by ambient light.
At least, that is my theory.

[chroniekon]

Watching also