Omega Owners Forum

Omega Help Area => Omega Electrical and Audio Help => Topic started by: geoffr70 on 29 May 2011, 21:34:00

Title: 12n Trailer electrics (again)
Post by: geoffr70 on 29 May 2011, 21:34:00
Hi peeps,

got Kevin the caravan coupled up today and took him for a short drive.

When i fitted my towbar I went by this info:

Colours on vehicle harness:

Black / Blue : Fog Light
Black / White : Turn signal, Left
Red : +12v permanent
Grey / Black : Tail Lamp Left
Black / Yellow : Stop Lamp
Grey / Red : Tail Lamp Right
Black / Green : Turn signal, Right
Brown : Chassis / Negative
White / Black : Reversing Lamp

Towbar cable colours are usually as follows...

Blue ------- Rear Fog Supply
Green ----- RH Flasher
White ------ Earth
Black ------ LH Side Lights
Yellow ----- LH Flasher
Brown ----- RH Side Lights
Red -------- Stop Lights
Purple ----- Rear Fog Lamps

I cut the plug off that is located in the boot, bared the wires and used block connectors. I also put in an indicator buzzer and followed the instructions that came with the socket.

The left indicator worked, with the buzzer, when the right indicator was selected the sidelight came on and no other lights worked. I stripped and reconnected the wires on the caravan plug but they were black all down the wires, not bare copper. I had the clusters off and cleaned all the connections up but no nothing works.

My caravan is very old so the electrics could just be paggered.

I am thinking about just getting a light bar and extending the wires. What does anyone think to that?
Title: Re: 12n Trailer electrics (again)
Post by: Kevin Wood on 29 May 2011, 23:32:34
Kevin the caravan indeed. Grr.. >:(

Well, if the copper in the wiring has turned black, moisture has got in. It may work but it's not good. I'd consider replacing the lead from wherever it connects inside the caravan to the 12n plug, as the plug has obviously been out in the elements and moisture has worked its' way into the wires from there.

Could well be that you have a wiring error though.

Can you try the caravan on a car with known good electrics and/or hitch up a known good light board to your car to check that? Then you'll know where to start. :y
Title: Re: 12n Trailer electrics (again)
Post by: Kevin Wood on 29 May 2011, 23:34:51
Your lightboard suggestion is a good one if the caravan electrics are poor.

I have a glider trailer that's left out in a field all year and only occasionally towed. I got fed up with replacing rotten light clusters and got a lightboard that lives inside in the warm and dry until it's needed. Problem solved.

Kevin
Title: Re: 12n Trailer electrics (again)
Post by: geoffr70 on 30 May 2011, 07:28:41
I'll use my dads van and hook the caravan up then I'll use the light bar. You're right I think there must be a wiring fault, also there were two black/blue wires, one I assume to knock the car fog off when coupled up, but the fog warning light comes on when headlights are on. Thanks Kevin
Title: Re: 12n Trailer electrics (again)
Post by: geoffr70 on 30 May 2011, 20:55:54
I've sorted it now - the earth had come off the crimp!
Title: Re: 12n Trailer electrics (again)
Post by: Kevin Wood on 30 May 2011, 22:49:28
BTW: The two black/blue fog lamp wires need to be shorted together for the fogs on the car to work. They are normally connected by a switch in the 12N plug (to disable the fogs when trailer attached) but these switches are so unreliable that I recommend just shorting the two wires. (so just check your car fog light still works). :y

Glad the problem is sorted though. :y
Title: Re: 12n Trailer electrics (again)
Post by: Lazydocker on 30 May 2011, 22:53:53
Quote
BTW: The two black/blue fog lamp wires need to be shorted together for the fogs on the car to work. They are normally connected by a switch in the 12N plug (to disable the fogs when trailer attached) but these switches are so unreliable that I recommend just shorting the two wires. (so just check your car fog light still works). :y

Glad the problem is sorted though. :y
Must admit, I just shorted them as I've never been bothered if I've had the fogs on with a trailer... It's not a huge issue
Title: Re: 12n Trailer electrics (again)
Post by: Andy B on 30 May 2011, 22:55:10
Quote
....
 but these switches are so unreliable  ......

Are they? since when?  :-? I had no problem with my 8 wire/connection GM 12N socket nor the GM 13 pin socket currently fitted. Fill the back of the socket with silicon grease & you'll even be able to disconnect it in years to come.  :y
Title: Re: 12n Trailer electrics (again)
Post by: geoffr70 on 30 May 2011, 23:16:30
Quote
BTW: The two black/blue fog lamp wires need to be shorted together for the fogs on the car to work. They are normally connected by a switch in the 12N plug (to disable the fogs when trailer attached) but these switches are so unreliable that I recommend just shorting the two wires. (so just check your car fog light still works). :y

Glad the problem is sorted though. :y

Ok thanks for that!

I tested it all with a light bar today, it was sat on the van storage box facing the car as I operated the lights.

You can imagine my confusion and frustration  :-/ when the brake lights also appeared to turn the fog light on (albeit very dimly), and the brake lights also activated the number plate light and made it brighter, and a number of other apparent faults!

After some alot of swearing and head scratching I realised it was the reflection from the car, and light leakage from the sides causing this  :-X How daft did I feel! :y
Title: Re: 12n Trailer electrics (again)
Post by: Kevin Wood on 31 May 2011, 10:14:42
Quote
Quote
....
 but these switches are so unreliable  ......

Are they? since when?  :-? I had no problem with my 8 wire/connection GM 12N socket nor the GM 13 pin socket currently fitted. Fill the back of the socket with silicon grease & you'll even be able to disconnect it in years to come.  :y

In my 12N socket the "switch" consists of a couple of bits of bent brass that separate when the plug is attached and thereafter fail to make contact again IME.

I can't remember the last time I used rear fogs let alone when towing so I'd rather not have the aggro of the fog light on the car not working at MOT time.

Kevin
Title: Re: 12n Trailer electrics (again)
Post by: Andy B on 31 May 2011, 17:27:41
Quote
Quote
Quote
....
 but these switches are so unreliable  ......

Are they? since when?  :-? I had no problem with my 8 wire/connection GM 12N socket nor the GM 13 pin socket currently fitted. Fill the back of the socket with silicon grease & you'll even be able to disconnect it in years to come.  :y

In my 12N socket the "switch" consists of a couple of bits of bent brass that separate when the plug is attached and thereafter fail to make contact again IME.

I can't remember the last time I used rear fogs let alone when towing so I'd rather not have the aggro of the fog light on the car not working at MOT time.

Kevin

Completely agree, but as said, even though the 'switch'is very basic (my 13 pin socket is the same - but the GM 12N was a proper switch) I wouldn't have said it was an underlying problem. Most towbars probably don't have any cut out switch.  ;) ;) ;)