Hi all,

This is a weird one and has me stumped.

I have put a towbar on my EF and went to the wreckers and removed a genuine plug so that I wouldn't have to tap into the wiring, (seeing as they are strange colours), eliminating any problems.

Everything seemed to go just fine. I checked the trailer lights one by one. Turned on the indicator, walked to the back, all good. Turned on parkers, walked to the back, all good. I kept doing this and varying the combinations. Tail + left. Tail + right. etc.

When it came to the brake lights I had to wait until the missus got home so she could press the pedal for me. This is where things got interesting...

If you are standing beside the car and put your foot on the brake everything is fine. No matter what combination you are using. Brake + indicator + tail all at the same time and everything is fine... until you sit in the car.

Sit in it and everything shorts and all lights are on and extremely weak at the same time.

Brake + left and the tail light comes on as well as both indicators but the right will be brighter. Brake + right and the opposite happens. Get back out of the car and test the brakes while standing and all is good again

Does anyone know what the hell is going on here? How can a standard EF Futura without power seats, or wiring to the seats of any kind, have a short just by sitting in it?

I might also mention that the cars electrics are fine whether you're in or out. It's just the trailer.

Got me stumped. Any suggestions will be greatly appreciated. Cheers

Seems like you've either got a broken wire, a bad earth or a faulty plug/socket connection. Did you solder all the wire ends before putting them in the plug & socket? Try using jumper wire(s) between the trailer & car wiring to see if it still happens (even one pair at a time).

as above has said .... BUT make sure ALL earths ARE good 1st as that is what i think it is


could also put it into fault mode [ie sit in brake & indicator] with someone watching trailer & bounce on tow ball . . . . . . . see what happens

Thanks guys,

I checked all the connections and everything seemed fine but the wife just got home from work and informed me that the central locking has stopped working. Looks like I've either done a fuse or that's where the earth is failing.
I never would have thought in a million years that the central locking could have somehow been tied into or shared an earth/positive line somewhere. I do know that the drivers side rear door has its wire loom visible from the sill to the door itself (about 30cm). Since the problem only happened when sitting in the drivers side I'll check there for any exposed wires in the morning.
Looks like the trouble shooting will have to continue.

check lights on vehicle without connecting trailer -
check wiring you have mentioned and also for wiring under seat that may be getting squashed when sitting in seat............look under carpet......
hold brake on with long screwdriver or piece of broom handle will save annoying the wife................