Not sure if this is the right place for this but I'll give it a shot. This just started a few days ago. First of all it is a 2004.5 Ram 3500, 5.9L HO. When I turn the key in the ignition to the "run" position the pump (Fass) now runs about 25 seconds, when it used to run about a second or 2. It is also very loud.

I can start the truck anytime during this 25 second run-up and then the pump will continue to run and stay very loud after start-up. If I let the pump run until it shuts off I can start the truck and the pump will not be running...initially. Then it will sporadically go on and off (again quite loud) but if I hit the accelerator as soon as it starts, it will stop...and then in about 10-15 seconds it will do it again.

Sounds like the pump is going but, then again, it could be a filter issue or tank issue. I checked the lines at the pump and they seem to be on clean with no air suction issues.

Thoughts? I am supposed to take a short trip (about 120 miles) on Monday and have little time to do anything with this.

 

FASS has a troubleshooting section on their website to help you determine the problem, that is the first thing I would do

Video here might help FASSride - FASS TV