Electrical problems are a well known downfall with Fiats. Because Fiat used aluminum wiring in many circuits and used relays because of the aluminum wiring, connections will deteriorate over time. The aluminum connections corrode and get that white powdery look that does not conduct electricity very well. I pulled every connection apart and painted all contacts with a copper conductive paste that eliminated my electrical problems. I also used the paste on the ends of the aluminum tipped fuses to insure good contacts.
I now sell this product due to popular demand. Its called KOPR-SHIELD. It comes in 1.5 oz container with a brush in cap. $12.95