Rear fog lights not working on RH Mk2

[James Agg]

I accidentally posted the same post twice re my suspension, and as I couldn’t figure out how to delete posts, I simply edited it and put in another one...

 

I’m getting nothing from my rear fog lights at all. I’ve done all the obvious things like checking bulbs/fuses etc to no avail. I ran a multimeter across the terminals of both fog clusters, and absolutely squat is going through there. I tested at the fog light switch end and I appear to have voltage registering at least up to the switch. I haven’t tried bypassing the switch to rule that out as I am not 100% certain on which wire bridges to which over the switch, particularly as whenever I had voltage passing through, the fog lights still did not illuminate when the circuit was completed by the multimeter. I’m assuming that if not a faulty switch, the problem is further down the wiring towards the lights themselves. Does anyone know of any common places for the loom to fail between the switch and the lights. My knowledge of car wiring is somewhat limited by comparison to my mechanical knowledge, particularly when the typical wiring diagrams I find in the Sierra Haynes manual make my head hurt!

Edited April 7, 2020 by James Agg

[maca]

May I asume that you are checking with the headlights switched on as the feed to the switch should only operate fog lights when used in that way?

[nicko]

Also, it may or may not go through a relay. So the switch could be ok, and the relay or associated wiring could be faulty. My fog light switch has a 12v feed when headlights are on, an earth for illuminating the switch when switched on and a feed to the fog light, which then has an earth to complete the circuit. As mine only has 1 fog light I don't have a relay.

HTH Nick

[Burney]

I've recently replaced my foglights as they weren't working.

Can you check the continuity between the switch and light fitting using your meter?

[phaeton]

Did the Ford switch gear ever only put the rear fog light on when only in the Dip position? 

[James Agg]

Hey all, for some reason I didn’t get a notification about comments on this thread. Yes I’ve tried lighting in all positions and yet my meter still displays squat at the light cluster terminals themselves. There’s definitely a problem going to the lights themselves. I found an old build manual that has a much more straightforward wiring diagram and so I will prod around with the meter and keep checking. The problem I have is that when I manage to identify any wires, they then disappear off into the black sheathed loom and without taking all of it apart, it’s hard to know where everything goes. If there is a relay for the fogs, I haven’t the foggiest idea (excuse the intended pun) of where it would be located, unless it’s behind the dash along with the indicator flash relay etc, assuming that my car even has a relay for the fogs...