I'd say 90% of the time we start the car it instantly comes up saying the o/s/f fog light isn't working. First time it did this I thought fair do's. You could give it a kick& it would come back on so went along to Halfords & nearly fell over at the £5.49 price tag or something stupid like that for a new bulb. Walked out very smuggly after christening my trade card & paying only £1.49 + vat
Anyway got home & replaced the bulb, switched on the front fogs & walked back round the front to admire my bulb replacement to find it was still not working Back round to the cab to check the dash & it was still showing as a fault so back round to the front to give it a kick (anyone'll think I've owned a Ford with all this kicking , I haven't honestly) to find the light is now working.
On keeping an eye on this like I said most of the time it will say the bulb's not working & you'll end up driving round with the indicator on the dash. If you turn the fog lights on, after a few seconds the bulb will light up & the indicator on the dash goes out & everything is fine. As I live out in the sticks I tend to drive round with front fogs on to keep the moisture at bay from the n/s fog then switch them of when I get into town & again the ndicator will remain off.
What I'm afraid of is someone will of heard of this problem & tell me it's the unit which runs the bulb check at fault .
Hopefully you won't & it's a dodgy connection which one day I'll get round to looking at. I'm with the second option as I recall this started when the roads started to get wet & mucky & I haven't heard of the faulty bulb check.