Planning the next
AO Silver Member
Join Date: May 2007
Location: United Kingdom
As the warning light isn't illuminating as well as the lights themselves, that means the problem ( if there is just one! ) is either with the switching device ( multi input relay ), the supply to that device or one of it's inputs.
Do you have a multimeter or a 12v tester?
When you say you've checked all fuses, can you confirm that you checked G391 on the auxiliary bracket? It's a 7.5A fuse and is in a brown fuse holder.
Assuming you have a multimeter/12v tester :
If the fuse is intact and with the ignition on 'MAR', check for +12v on both terminals of the fuse holder ( you should be able to get the test prod in with the orange wires ). If you get +12v on one side and not the other, you have a problem with either the holder or the fuse. If you don't get +12v at all, you have a problem between relay I108 ( ignition controlled cut off relay ) and the fuse holder.
If you do get +12v on both fuse terminals, test for +12v going in to the rear fog device ( ignition on 'MAR' again ). There will be 7 wires going in to the device holder. You want the orange wire and like the fuse holder you should be able to test for +12v via the cable entry.
If you get +12v on the relay ( I'll call it that now as it's easier! ) input, you can now check the ouput side. Remove the relay from its holder. Look for the Grey wire ( be careful, there are also Grey-Red and Grey-White wires ). With the ignition on, temporarily bridge the Grey wire with the Orange wire. The warning light in the instrument pack should illuminate. Remove the bridge wire. Repeat for the the Orange wire and Grey-WHITE wire. The fog lights themselves should come on. Your bridge needs to be able to take up to about 4 Amps!
If all that checks out, the problem lies with the 'relay' itself, the switch or one of the inputs.
Let me know how you get on and they can then be tested.
Last edited by pkr; 30-10-12 at 07:39.