Rear Fog Lights Not Working

Paul Dunster · Apr 26, 2006

Help,
I've spent all winter rebuilding the engine and its now running. MoT booked for Saturday, so checking the rest of the car over and tested the lights but can't get rear fogs to work. I have never used these lights before so not sure how they will turn on, I have even resorted to the Handbook!!! The Handbook talks about a 2 position switch but mine is an 83 car with individual switches for the front & rear fogs. I've tried all combinations of lights operated but nothing from either rear fog, checked the bulbs and OK.
To switch on is it just pull the switch out with the side lights on? Done this and switch light comes on.
There is no mention in the Handbook or Bentley manual of fuses or relays for the rear fogs, do they connect straight from the switch?
Any help appreciated, I want to get the car back on the road for May.

sentwistle · Apr 27, 2006

I know this is not a proper fix but my experience of MOTs with my various classics over the years, is that it is worth putting it in and see what it fails MOT on. Unfortunately (or fortunately) things do get missed.

Steve E.
Silver 3.2 Coupe

PS I'm sure you have tried this but I noticed one of the fogs will only come on when the full lights are on and when the other fog is already on. I think that was the frts though will only come on after the rears are on. Might be wrong on that one.

bones · Apr 27, 2006

Paul look inside the front fuse box and the diagram may well reveal a relay I have one in my 78, if you find it swap it with another black one and see what happens. Repalce the associated fuse and clean it's contacts. I fyou are still stuck repost and I'll see if I have a wiring diagram for your year.

Geoff_Fields · Apr 27, 2006

Don't forget that the headlights must be on first. Sidelight switch on will illuminate the fog switch at low power. When fog switch is operated it should increase in brightness. However the common cause for failure of fogs is the vunerable exposed wiring going to the lamp or corroded terminals in the lamp assembly.

Paul Dunster · Apr 27, 2006

Thanks for the help.
I had a good look underneath and the wiring around the exhaust was broken, so I have implemented a tempoary repair, another job to add to the list!!
To answer my own question for future reference, to turn the rear fog lights on just pull out the switch with the side lights on.
Fingers crossed for the MoT Test on Saturday.

Cheers,
Paul.
Red 911SC.

Guest · Apr 28, 2006

Good luck with the MOT...
You should be OK but if it fails let me know first before you spend any great chunks of cash. I'm a tester myself and it never fails to surprise me what some of the more unscruplous among us fail cars on. I even heard of a car failing for not having a red triangle on the hazard switch... I kid you not.
That said we had a 911 in last week that failed on a leaking brake flexi pipe. This is obviously dangerous yet the customer was having none of it! Was insistent that it be passed or he was going to call the ministry about it. We gave him the phone number....

Paul Dunster · Apr 28, 2006

Thanks for the offer, I hope I won't need it. I have been using the same garage for my MoTs with my other classic MGB 68 roadster and they are very realistic but as you say make sure that safty is correct. when all is said and done I don't want to drive around in a dangerous vehicle!!
I'll let you know how I get on.

Cheers,

Paul.

eleanorb · May 17, 2006

Hi Paul,
Try putting your head light on, pull the switch out to and twist clockwise.

Brad

Paul Dunster · May 18, 2006

Hi Brad,
Thanks for the reply.
I did solve the problem, the insulation on the wiring had perished in the heat from the exhaust. I did a tempoary repair to get through the MoT.
The rear fog lights will actually work with only the side lights switched on.

Cheers,
Paul.
1983 911 SC