Motohome wiring for lights drama.

Bulb Failure warning on a Fiat Camper, The owner took it to the Main Dealer twice… still not right, they just made matters worse , trying to sort the wiring for lights! Now the stereo won’t play, removing the Pioneer CD, stopped the engine from starting! Nightmare!!! After spending over 5 hours studying the problem, including the trailer wiring all is now well. We found a short in the speaker wiring, at the front passenger door, also a dry joint on the main earth point under the dash in the camper.  You know it pays to use an Expert, we have all the info, wiring lights diagrams and over thirty years experience too!