Fog light won't work.

[Doobit]

I replaced the fogs on my 1989 chromie cab as they were rusted and cracked and neither was working. I put in New housings lenses bulbs etc. One of the lights still doesn't work.

Anyone any ideas on why this could be? Hoping there's a fuse blown but I assume neither light would work if this is the case. Just hoping it's not a problem with the wiring loom.

[brutus]

give the switch a clean on the contacts,

[Sanchez]

If one light is working then the switch will be fine, relay and fuses all good.

Have you swapped the bulb from one side to the other?

Are the contacts in the fog light housing clean?

Have you tested for 12volts?

[Brianmoooore]

The foglights are controlled by a relay, operated by the foglight switch. Since one light is working, the relay, switch and the rest of the control circuit must be fine.
Power is fed from the relay to the two foglight fuses, 29 and 30, and from there, individually to each of the foglamps, and from the lights there are also earth return wires to the earthing point on the front of the LH inner wing.
The first thing to do is to swap over the two fuses, and see if the fault stays where it is, or moves sides. A blown fuse is not always as obvious as you may think.
If the fault stays as it is, proceed as Sanchez says, and check for 12 volts (with a 12 volt bulb, NOT a meter) at the foglamp plug, between the two pins. If the bulb doesn't light, connect the test bulb between the live pin of the plug and a good body earth. If it now lights, the problem is with the earth wire; if it doesn't, the the problem is between the fusebox and the light. If the test bulb lit when you connected it across the plug, the problem is within the foglight itself.

[Doobit]

Guys thanks for your help on this. Exactly the advice I needed....wisdom beyond words!

[Sanchez]

Guys thanks for your help on this. Exactly the advice I needed....wisdom beyond words!

Nothing less from Brian. Very knowledgeable person.