I installed a low pressure warning light from Blue Chip Diesels. The pressure switch attached to the fuel fiter housing and a yellow warning light place in the instrument panel. I just had to run a hot wire from the fuse box under the dash through the light and back to the switch that went to ground. Well worth it for peace of mind. I also carry an upgraded lift pump which I need to install at some stage. There are several companys that produce the warning system.
1998 Rexhall Anthem 34' DP, Cummins ISB, Allison 6 speed, Spartan Chassis, 300 watts solar.