I have been told that moisture gets inside the fuse box causing the fuel pump fuse to malfunction and this is the reason that my car will not start on humid days or on rainy days. To me that all sounds strange. He also told me that the fuses must specifically be Volvo fuses and the right voltage of course. Secondly, the distributor cap had a bad gasket which was also causing moisture with the contacts, and is thus preventing sparks. Is there a way to seal up the fuse box to prevent future moisture from getting inside it?
For this, Silicone spray is one tool I personally like to use especially on rubber or silicone seals. The spray will leave a water-tight film on the electrical component and offers a moisture resistant coating. If you would like to have this checked, an expert, like one from YourMechanic can come to your car’s location to inspect the electrical system in order to scope the problem out and pinpoint any problems.