dual fuel tank trouble shooting

[chris989]

Hello all

2002 2500 burb 6.0

I have low fuel pressure and need a new something. During diagnosis, i discovered this model has the dual fuel tanks and a unessesarliy complex system.

I have been reading for an hour now and can not find out how to determine which pump or module is bad. Apparently the rear tank gravity feed the forward tank (unit the fuel is too low then it pump).. So in this system there is a rear lift pump, main/forawad tank pump and a handfull of modules to make transfer seamless. one article says when the main tank is x/3 full the rear pump cycles bla bla bla..


anywhooo,, the gauge reads 1/4 on the dash,, I get 30 psi at the rail after it sat overnight, started, ran, dies now zero PSI..


two thoughts,

Rear pump failure and the main pump is running dry resulting in th elow pressure,

OR

the main tank pump is bad.

If the sender is on the main tank, and reading 1/4, then it would be the main/forward pump that is bad?


Thank you,
Chris