Modulite trailer wiring: In the middle and getting frustrated

sayn3ver

Active member
Joined
Jul 18, 2011
Location
NJ
TDI
none
Sank a whole day and night into this.
Here is the quick rundown.

Car: 2011 Golf Tdi 2 door

Passenger side :
Black and Purple wire: I believe to be the brake/tail lights
Brown wire: Ground
Black and green wire: right turn

Driver side:
Black and red wire: Brakes/Taillights
Brown wire:ground
Black and white wire: Tested...get 0v to 12v on off with left turn signal on.


Modulite:
White=ground
Brown=tail lights
Red= tail/brake lights
Green=right turn
Yellow= left turn

what I have......

I have the white and brown modulite wires grounded on a stock grounding location with a round stacon terminal.

I have the red wire hooked up to the passenger side black/purple wire.

I have the green wire hooked up to the passenger black/green wire.

I have the yellow wire hooked up to the driver side black/white wire.


My trailer tested fine on my dad's f250.
Currently on my car the trailer does this:

Running lights(all trailer lights on): work
Right Turn signal: work
Left turn sign: no work
Passenger side brake light: work
Driver side brake light: no work

I am banging my head on the wall. I don't see how the trailer's tail lights are both seeing power but only the passenger side blinks or brakes.
 

sayn3ver

Active member
Joined
Jul 18, 2011
Location
NJ
TDI
none
broke out the meter this morning. All my car wiring was good. I had previously tested the trailer so I initially thought my issue was with the modulite wiring or the unit itself.

Turns out the solder joint on the trailer's driver side turn signal was broken...must have happened when either my dad or I have been moving it about the yard recently.

Talk about not using my head. should have pulled the meter out early yesterday and saved me a bunch of head aches.


For the record for those who are wondering about the regular old 2011 Golf 2door Tdi.

Driver side:
Black and white = turn signal
Brown= ground
Black and red = brake/tail lights

Passenger side:
Black and green = turn signal
Brown = ground
black and purple = brake/tail lights

Problem solved. Towing her tomorrow to the shore for some backbay fishing.
Let me raise a toast to my Fluke T5.
 

fastson

Well-known member
Joined
May 14, 2012
Location
Sweden
TDI
2013 Golf 1.6 TDI BMT DSG7
Glad you got it in the end. :)

Me and my brother once spent a month trying to figure out an electrical problem on his 93 Mercedes. After all the searching, swearing and pain it turned out to be a cable with a bad connection (it was sitting there in plain sight the whole time).. DOH.
 
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