[Fireman87]

I had a post about this issue with my fuel filter light flashing about two weeks ago. I have since replaced my fuel filter and the light is still flashing randomly and sometimes when my WTS light is on the FF light stays on until i start the engine. What else could be the cause, bad sensor, someone mentioed a fuel pump in my last post. Thanks guys and merry christmas!

-shane

 

[RD97]

As I recall, the fuel light has a constant 12V to it whenever the ignition is in Run or higher. The WIF module and filter restriction sensor then activate the light by providing the ground path. There have been several posts in the past mentioning that the wiring insulation down in the valley has been melted or dissolved (presumably by repeated exposure to diesel fuel). So this might just be an issue of the wiring shorting to ground somewhere in the harness.

In addition to inspecting the wiring, you could always plumb in a temporary pressure/vacuum gauge on a short hose and tuck it up under the windshield wiper. That would help isolate it as a mechanical or an electrical issue.
-RD

 

[Fireman87]

thats a good idea, thank you. what type of numbers should i be looking at for pressure? Ill also check bazz's site for info.
shane

 

[obs96psd]

My fuel filter light comes on at times when using the front tank. I have drained the front tank and now only use the rear tank.

One of these days I will drop the front tank and look for a restricton.

 

[RD97]

It's actually pretty easy to drop the front tank. All that's required is:
1) 30' of rope (use it to make a sling so you can lower it gently)
2) 5/16" socket and swivel on a 10" extension (for the filler neck hose clamp)
3) Fuel line QD tool ($5 at parts store, size E & F, if I recall correctly)
4) 13mm and 15mm wrench for the strap bolts.

I've done it a couple of times now, and it only takes about 10 minutes coming out, and 15 going in. The selector valve seems to do a good job of not leaking, so if it comes down to it, I wouldn't worry about driving with the tank out (I've been doing it for a while now).