Wiring trailer mindboggling

[David the spud man]

Hi this is mind boggling can't figure it out so the i have bought a n secondhand jeep so when I connect up trailer to the jeep and plug in lights turn lights on everything works then when I start the engine after a few seconds the taillights go out on the trailer only jeep tailights still work and every other light works on the trailer and jeep just the tailights go out on the trailer any help will be appreciated greatly thanks

 

[Andrew]

Is there some kind of safety overload on the jeep - how old is it?

Are all the trailer tail lights wired to the same pin? The lhs lights (black wire) should be pin 7 of the socket, the rhs (brown wire) should be pin 5. Some manufacturers put them both on the same pin which can cause overload.
Beware though - the manufacturers that do this don’t tend to use the standard wiring colours either.

 

[David the spud man]

Hi shes 2008 ill check 7 pin plug there

 

[Lincsman]

Hi shes 2008 ill check 7 pin plug there

Some cars (mondeos certainly) need a laptop to tell it to allow trailer lights to work... on the mondeo it was only the tail lights that wouldn't work until programmed.

 

[dundee dave]

Hi this is mind boggling can't figure it out so the i have bought a n secondhand jeep so when I connect up trailer to the jeep and plug in lights turn lights on everything works then when I start the engine after a few seconds the taillights go out on the trailer only jeep tailights still work and every other light works on the trailer and jeep just the tailights go out on the trailer any help will be appreciated greatly thanks

i had same thing on a suzuki jimny it turned out that one of the stoplight bulbs faulty replaced bulb lights all normal might be worth a looky. did not believe sparky i had look at it but he was right.

 

[David the spud man]

Sorted now touch of a power draw so change side markers to led and its sorted

 

[dundee dave]

thats good your sorted electrics can be a nightmare.

 

[David the spud man]

thats good your sorted electrics can be a nightmare.

Unbelievable sometimes easier to start from scratch

 

[TripleSix]

I would suspect the vehicle has bodged towbar wiring and should have a bypass relay fitted to take the load off the BCU.

 

[David the spud man]

I would suspect the vehicle has bodged towbar wiring and should have a bypass relay fitted to take the load off the BCU.

Yeah relay is prob wanted

 

[335d]

What jeep is it?
on some of the older ones, the trailer wiring is there, just needs an additional loom. But some people love the old scotchlock connections into the taillight wiring.

 

[Lincsman]

What jeep is it?
on some of the older ones, the trailer wiring is there, just needs an additional loom. But some people love the old scotchlock connections into the taillight wiring.

Usually because the loom costs more than the towbar, I solder connect bypass relays in.

But i have had to use the loom sometimes so it can do its stuff regarding traction control etc.