'99 dual tank issue.

compressorguy · March 30, 2005

my '99 is a modified work truck. to accomodate some of my equipment, the factory tank inside the framerail has been removed and replaced with an aftermarket located above and outboard the framerail.

the problem i'm having now is that:

1) i don't know what gauge level to put in my new tank (the one that came with it is a 'conventional' 70ohm gauge) to get a correct reading and,

2) the new tank will run out of fuel while the the rear tank is nearly full.

so, who knows how these tanks are supposed to work. are they switched manually? i haven't found a switch anywhere.

the other thing is since i don't have a fuel gauge that works in the new front tank, when i first start the truck, the gauge will go up to nearly 1/2 full (when the rear tank is full) and stay there for ~5-10 seconds, then it falls to empty.

i believe that the rear tank pumps to the front tank during this time but no more. is it supposed to pump at a regular interval?

any help is appreciated. thanks!

Mattt · March 31, 2005

I had a similar problem in a '96 stakebed w/ dual tanks. There is a control module that runs the transfer pump in the rear tank. Mine went out repeatedly along with the transfer pump. It transfers fuel from the rear tank to level the amount in the 2 tanks I think.

It was getting really annoying when the gauge would show E, and you'd pull in to a gas station and the front tank would be empty, with the rear tank full.