church.andrew.d

Hey guys,

I am having some trunk issues that appear to be pretty common to the W208 and to Mercedes in general. I've done some pretty thorough searching and found some great tips, but have reached a bit of a dead end in terms of troubleshooting.

Note that about two weeks ago I had all of the trunk panels apart while tightening down my rear shocks. While doing this, I found a moderate amount of standing water on the left side of the trunk along with slight signs of corrosion. On the right side the carpet down below the CD changer was also very wet. I dried everything off before putting a few plugs here and there, unclogged a couple of drains etc. to try and seal everything up a little better.

About a week ago I noticed the trunk open switch on the console was lit when it shouldn't have been. I noticed as well that the interior trunk light wasn't functional. However, the interior trunk switch and remote trunk switch on the fob continued to open the trunk. Three days later, neither the switch nor fob will open the trunk. I got it open with the mechanical key, removed the central locking vacuum pump/motor from the left side, reseated all connections, and both the interior switch and remote fob are now working again. However, the interior trunk switch light is still on and the trunk interior light is still off.

Additionally I noticed that the car will lock but not arm itself. I.E. the lights do not flash when I lock the car via fob, although the car does lock. When I trigger the alarm via the fob, the car's lights flash but there is no alarm sound. I also noticed that fuse F5 in the rear fuse box is blown and replacement netted me only an additional blown 5A fuse. The interior trunk lamp itself appears to be fine. The car does display a "LAMP MALFUNCTION" warning in the dash, but has been doing so for months. As far as I can tell all exterior lamps are working and the trunk light was working fine for 5 months or so while this dash warning was present.

I guess my next step is to start tracing the wiring back from that fuse and look for a bad ground somewhere, but I wanted to see if anyone else might recognize this problem and know of a different solution.

Thanks for any help,
Andrew

Andy Casson

Hi Andrew
Did you ever solve your problem I have exactly the Same

MARK CUMMINS

Check the wire harness to the trunk pin switch..I have seen several where the wires were worn through and caused a short...

Andy Casson

Thanks for the info will have a look at the weekend and trace the wires will report back

Thanks again

GatorMB

Mark is correct, I found melted cabling insulation in the trunk light circuit while investigating lighting issues.

Since the repair of wires the trunk timer does not work but I can pull out the white pin switch to dis-arm the trunk lamp.

Cheers, Gator

Andy Casson

Thanks
That's were I'll start will report back
Many thanks

Johnal

Hi, I have the same issue, is the trunk pin switch usually the culprit?

Andy Casson

Hi I've checked the switch
Disconnected everything and the fuse still blows
I've checked the wiring in boot all looks good
Also when I lock the car with remote it's locks up but light don't flash
Having to use key to open boot will not un lock on remote
Switch on centre console will not open boot
I was going to check out the switch next will try at weekend

GatorMB

Something must be open or shorted in the central locking system, many circuits involved but you will have to get creative in narrowing them down and explaining it here.

Gator

last thought: trunk(boot) latch

Andy Casson

I did have to soak the boot latch in we'd 40 to get the key to work I will try both the boot latch and the switch at the weekend by disconnecting them both and seeing if the fuse still blows as you say I will have to start making a list a narrowing down
Regards and thanks andy

MARCMASEMAN

TRUNK LIGHTS
The left license plate light stays lit always.... even with key off and removed. I removed trunk prior to this problem. Did I rewire it wrong? Where can I get a wiring diagram for trunk????