Ducato 2.2 2007 Motorhome. Bulb warning light is illuminated but no bulb failure. This is potentially an MoT failure but how do I correct the fault or reset the warning light?

Wrong wattage bulb fitted. Or LED.

The system monitors the power used

This happened to me on my doblo. I started checking the connectors on every buklb. When I took the side light holder out to check the connections the bulb dropped out, proving to be very loose. I made it a tight fit again and Hey Presto!!!! warning light cleared. Hope this helps.

I had this with my GP, everything worked and connections where so clean after the umpteenth time of cleaning I sadly admit measuring the resistance of all the lamps, one had a much higher resistance in comparison to its opposite number, It worked fine but it was responsible for the fault light.

I have this sometimes with my Bravo. Poor bulb getting ready to fail and anything other than perfect contacts seems to do it. Once I worked out which bulb was playing up changing it stopped the issue and its never recurred.