Rear fog light won't work - could it be trailer socket problem?


My Fourtrak's high intensity rear light will not work. The bulb is OK and the tell-tale dash light comes on when the switch is on.
The vehicle has a Daihatsu tow bar with trailer socket wiring.
I've heard that there is a micro-switch in the socket which switches off the rear fog light when the trailer plug is inserted.
Might the problem lie with this micro switch?


i had this problem with mine, turned out to be a bad earth on the light, try cleaning the connections first, as fourtraks rear light wiring is a bit of a weak point as it is all open under the bodywork.
hope this helps regards mark


Thank you for that. I'll give it a try. It's good to know that I am not the only person in the world with this particular problem!

fog light

if you look into the socket at the bottom theres a wee black pin that disconnects the foglight when you connect the plug to save blinding youself when your towing have you tryed that it keeps sticking on mine a clean and light grese usually sort it hope this helps jamie


fog light

Same problem. As I do not own a trailer I disconected the multipin plug/ splitter,near the tow bar, which took a feed to the trailer socket, which was inserted ito the wiring loom near the tow bar,and just reconnected the plug leaving the splitter section hanging free,on looking closely at the trailer feed two of the wires had corroded through,where they exited the splitter, all rear lights worked ,no problems, one day I will fix the splitter,just in case I have to use a trailer.

Edward (ews) '92 Fourtrak 2.8 TDX

Quite a few people end up bin

Quite a few people end up bining the whole rear fog light wiring loom and starting again. The wiring is a week point on the old girls genrally. Also the rear fog is earth switched, which can cause problems.

Any veiws expresed in this thread by me are purely from my own experience, and (sometimes) falible memory. Hope my comments help, but please don't take them as gospel.

Dodgy fog lights

I put my fog light on the other day in some crappy weather, and the next time I looked at the dash I'd lost all my display lights. On pulling over to check it out, I also discovered that I'd lost the whole back end lights, plus my front side lights. Quick 15a fuse swap, no biggie, but you're right, the wiring on these things is a bit dodgy. Does it never rain in Japan?

bad wiring

have heard the wires at the back can chafe on chassis so if afuse has blown it might be an idea to check its not rubbing anywhere.

rear fog light!

My Fourtrak failed its last MOT on seat belt fastening and rear fog light! I checked all the obvious stuff like bulbs and all the wiring I could see and still couldnt locate problem. Turned out to be chaffed wire further along inside car and took the mechanic only a few minutes to spot. At least i'll be a bit wiser next MOT time. Cheers

That rear fog light!

Guess what? Mine has done exactly the same thing! No fog light so failed the MOT. Currently beeing looked at. Very nice motor shame about the crappy wiring!!

Fine when its going but a pain when it's not!

We've got it working

The problem was, as suspected, with the trailer socket. The relevant bit of the wiring to the socket has been by-passed and the rear fog light now works. I shall live with the reflected glare from the thing if ever I am towing anything in the fog at night!

Thanks for all the helpful advice everybody.

Fourtrack rear foglight.

Foglight now working and yes it was the trailer socket. Backed into a post and cracked the socket so only me to blame and not the Fourtrak

Fine when its going but a pain when it's not!