wires coming out of relay fried a long way and melted other wires on the way. Fixed wires, changed relay.. tested fine, ran good for about 20 minutes then did same thing again? fyi i replaced fuel pump 2 mos ago with a used one that worked fine.
Electrical melt down at the constant fuel pressure relay on 1994 Volvo 850
you obviously have a short in the system poss a pinched wire. rec you seek help on this as it will take some testing to determine issue