Auxillary power socket in boot. W169

Biggles1957

Senior Member
Joined
Jul 31, 2019
Messages
64
Reaction score
18
Your Mercedes
W169 A Class CVT A180 2006 Elegance
I had a W168 in which I fitted a power socket in the boot. I'm sure I remember there being a pair of wires terminating in a connector behind the left hand stowage compartment in the boot (where the jack etc is stored). I can see what looks like a 'knockout' blank in the plastic liner in the same place in my W169 but before I start making holes I thought I'd ask if anyone knows if the wires are there hiding behind. Reason I'm asking is I've just fitted a towbar and am looking for a power supply at the back end rather than running a wire all the way forwards to the battery compartment. Wiring instructions on the relay box say to connect (via an in-line fuse of course) direct to the positive terminal of the battery, but I think I'd much rather it be on an ignition controlled circuit. I can't really see a reason for it to be permanently live? Any advice much appreciated!
 

Tony Dyson

Senior Member
Joined
Aug 26, 2018
Messages
4,038
Reaction score
2,585
Location
God's Country
Your Mercedes
2014 C 220 CDI W204 OM 651
What if you wanted to leave your sidelights on a connected rig with your car locked and unattended?
 
OP
B

Biggles1957

Senior Member
Joined
Jul 31, 2019
Messages
64
Reaction score
18
Your Mercedes
W169 A Class CVT A180 2006 Elegance
  • Thread Starter
  • Thread starter
  • #3
I see what you mean but I only want to tow a little trailer to fetch stuff for my chickens so would never need to do that.
 

mattkh

Senior Member
Joined
Aug 2, 2006
Messages
3,158
Reaction score
353
Location
England
Your Mercedes
A160 W168 1999 1.6
How much current are you hoping to draw from this supply..?
 
OP
B

Biggles1957

Senior Member
Joined
Jul 31, 2019
Messages
64
Reaction score
18
Your Mercedes
W169 A Class CVT A180 2006 Elegance
  • Thread Starter
  • Thread starter
  • #5
Only for a small trailer Matt - so if the brakes and an indicator were on all at the same time that would be 3 x 21W so around 5 amps. I was going to fuse the supply 15A (maybe only 10A).
 

mattkh

Senior Member
Joined
Aug 2, 2006
Messages
3,158
Reaction score
353
Location
England
Your Mercedes
A160 W168 1999 1.6
Thanks.
And the rear sidelights..?
I dont fancy recommending the fuel pump circuit, because in case of an overload, the car would stall.
How about the live to the aerial amplifier in the roof.
 

EmilysDad

Senior Member
Joined
May 8, 2012
Messages
12,120
Reaction score
5,664
Location
Bury Lancs
Your Mercedes
ML350
is there not a SAM or fuse box of sorts at the back of the car without going to the battery? My ML350 (W166) has a fuse box under a rear seat with spare fuse points on the side, both permanent & ignition live.
 

mioba

Senior Member
Joined
Feb 19, 2006
Messages
7,898
Reaction score
4,657
Location
Nottingham and Köln
Your Mercedes
W124/E200, W220/S320CDI, W205/C200, W251/R350CDI 4Matic
Would the thin wires of a lighter socket be able to handle the current for a trailer (max would be fogs, no plate lights, brakes and indicator) at once I would say.
Be safe OP and check!
 
OP
B

Biggles1957

Senior Member
Joined
Jul 31, 2019
Messages
64
Reaction score
18
Your Mercedes
W169 A Class CVT A180 2006 Elegance
  • Thread Starter
  • Thread starter
  • #9
I completely forgot about side lights! LOL! I guess because I won't be using it very often and the tip isn't open at night! What a plonker! I thought the lighter sockets were fused/wired for at least 15 amps or thereabouts? It's just a bit of a pain running a wire all the way to the main fusebox/battery but I'll have a proper poke around...
 

mioba

Senior Member
Joined
Feb 19, 2006
Messages
7,898
Reaction score
4,657
Location
Nottingham and Köln
Your Mercedes
W124/E200, W220/S320CDI, W205/C200, W251/R350CDI 4Matic
Just out of interest was there no wiring plug with the tow bar you fitted.
Surely its illegal (but I didnt look) to use a trailer without functioning brake lights and indicators at least.
 

Blobcat

Moderator
Joined
Feb 8, 2006
Messages
38,787
Reaction score
27,423
Location
Grange Moor
Your Mercedes
R171 SLK280, Smart R451, Land Rover 110 County SW, 997 C2S, R1250 GSA TE 40th, CBR600FP
@ZZZZ might have some info, although he’s not been around much lately :(
 

sonic

Senior Member
Joined
Nov 21, 2009
Messages
3,578
Reaction score
2,382
Location
Staffordshire
Your Mercedes
E350CDI, SLC250d, FJR 1300
Any wires in the boot will be on the ignition circuit, so when you turn your ignition off you loose your trailer lights.
I would run a cable up to the front of the car for power, too much risk damaging the harness.
 


As a member of ourMercedes Owners' club, you will enjoy numerous savings on an expanding range of services including, Insurance, Parts and Servicing, RAC Membership plus much more.MBOmembers can save around £200.00 a year. You can join from as little as £30.00 and start to enjoy these savings immediately. You receive our monthly magazine and free classified ads when you decide to trade up a model.
Top Bottom