Well I have a 99 disco 2 and the factory foglights where working fine then one day I saw one wasn't working so I put a bulb in it and it still didn't so I took the bulb out of the other foglight to see if it was the bulb and it still didn't work so I bought two new bulbs for the foglights just to see if I could get one of them working again then figure out the problem with the other well now neither foglights work with two new bulbs. So I check output of the foglights with a multimeter and sure enough both say they have 12volts. So whatsgoing on thats allI thought there was to it????

 

Were you trying to run the fog lights with your high beams on? If so, there is a relay that won't allow the fog lights to come on except when the low beams are on. I am also going to assume you checked the fuse in the engine compartment?

 

I also have a '99 dII and my fog lights will come on with or without my high beams being on. Is the indicator light on the switch lighting up? If it is, check the fuses first. Second, check and clean the bulb connection, and the actual light connectors under the bumper.

 

and make sure not to touch the bulbs when you put them in. They will burn outfast if you touch them.

 

Well I was guessing if I check the output with a multimeter and was getting 12 volts then everything to that point had to be good such as fuses, low beam and foglights all on. I did check fuses and everything before the multimeter though and I had low beams on and the green light on the fog light switch is on but still nofoglights. I was wondering how does the ground work because with a multimeter I ground the lights on the frame and I just check to see if it is getting voltage and they are so I was guessing my only problem would be ground so how are they grounded?

 

Very true!!

 

Yes I believe your having a ground issue at some point. I would try with the plugs installed to run an additional ground to the bulb. If the lights come on then your having a ground issue at some point. Then you have a direction to take.