2013 aftermarket radio only works when vehicle is off

Colt2056

New member
Problem: radio only works when vehicle is off.

Hello, I have a 2013 sprinter cargo van it originally came with a single din radio working perfectly fine. I'm swapping it for a double din touch screen.

When I connect the OEM radio harness to the supplied connector that plugs into the back of the new radio everything fits fine. I have done no cutting or splicing of wires.

The problem is the radio only has power when the vehicle is off. As soon as the key is put in the ignition or a door is opened the unit shuts down.

No blown fuses no disconnected wires.

Has anyone else experienced this issue?
When I use a volt meter I read 12v on two parts of the OEM harness one which connects to the B+ of the new radio and one that connects to the ACC of the new radio

When the vehicle is on the voltage at the B+ stays hot and the voltage at the ACC drops to 3 volts and the unit shuts down.

This should be a plug and play setup.

Shouldn't I be getting 12v from the ACC ONLY when the key is in the ignition?

Anybody ever run into this issue or have any insight?

Thanks in advance for the help.
 

autostaretx

Erratic Member
Well, here are some 2007 wiring diagrams (which probably pertain to the 2013).
MB had at least 3 different wiring schemes, depending upon the original option (radio pre-wire, specific models of radios)
The 3rd party diagram presents them as three pages, i haven't looked in the official MB diagram to see what they say.
The official diagra also has connector pin-outs in section 8W-80, which may help with the sockets you have.

http://www.diysprinter.co.uk/reference/2007-sprinter-wiring-information.pdf <- wiring diagram from above
http://www.diysprinter.co.uk/reference/2007_Wiring-sprinter-2500.pdf <-- 3rd party wiring diagrams

The NCV3 doesn't have the "classic" multi-leaf rotary switch of older cars (including the T1N).
Instead, it has an "ignition switch" module which sends CANbus messages to the Body Control Module which then "generates" the ACC, IgOn, and other such signals.

--dick
 

red_johnny

Active member
Sounds like the adapter plug could be wired wrong. The constant wire is probably hooked to the switched power and the switched power might be causing an issue somewhere else. Look at the pin out from the post above and find all the powered wires going to the radio. Then figure out where they are supposed to go into the aftermarket radio. Some radios have the pin out on the top of the radio. Otherwise look at the installation guide for the radio or the manufacturers website for that information. Additionally I would check the fuse for the radio and the van radio fuse. Lastly I would find a solid ground and ground it directly from the radio to that point. Too often factory radios do not require as heavy of a ground as aftermarkets do.
 

pbansen

Active member
No, it's not a wiring issue, unfortunately.

I had the same issue when installing a similar aftermarket unit in my 2008 NCV3. The issue is Canbus connectivity. I had the same issue with two different aftermarket receivers (returned the first one, thinking it was defective) and finally solved the problem by purchasing and installing an Axxess AX-ADXSVI, which is an autodetect interface for aftermarket receivers in a Canbus system. The stereo (a Kenwood) now works perfectly, exactly like the Mercedes (actually a Becker) unit that I removed. I got the Axxess unit from Amazon - they are about $46.

Hope that helps!
 

red_johnny

Active member
No, it's not a wiring issue, unfortunately.

I had the same issue when installing a similar aftermarket unit in my 2008 NCV3. The issue is Canbus connectivity. I had the same issue with two different aftermarket receivers (returned the first one, thinking it was defective) and finally solved the problem by purchasing and installing an Axxess AX-ADXSVI, which is an autodetect interface for aftermarket receivers in a Canbus system. The stereo (a Kenwood) now works perfectly, exactly like the Mercedes (actually a Becker) unit that I removed. I got the Axxess unit from Amazon - they are about $46.

Hope that helps!
I keep forgetting about that Canbus stuff. Makes perfect sense now. Most of the radio kits I have done came with the canbus module. That should be a pretty easy fix.
 

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