Truck in question is a 99 5.3 ecsb Z71 bone stock. First of all, the fuel gauge jumps around like crazy, I know on the 03+ models it is stepper motors at fault, but from what I've read, it seems that on these trucks it is the fuel sender at fault correct?

Second, the abs and brake dummy lights are lit on the dash. The wheel bearings don't seem to make any noise, but is it common for the abs sensor on the hub assembly to go out without the bearings going out also? Or would this been the abs motor/module at fault? If so, what would be a way to troubleshoot this problem.

Third, the truck seems to stay engaged in 4wheel drive. The lights on the pushbutton flicker when they decide to come on at all. We can't hear it disengage or engage when we press buttons. The service 4wheel drive light comes on also. Would the button panel not working cause this light to come on, or would the actuator not working cause this light to come on. I know if the actuator broke it would not engage or disengage. What else could be at fault here?


Thanks,

Will

 

1) Fuel sender in the tank is the common culprit...there was a thread around here recently where guys were buying the sender on ebay dirt cheap (less than $30 IIRC)

2)There have been problems with the speed sensors getting dirty with debris and rust, there's actually a recall. You could try removing your front speed sensors and cleaning them.

3)Sounds like you have a bad switch in the dash, it's also very common. Mine went on me a few years ago, the lights would behave irratically and the "Service 4wd" message illuminated.

*EDIT* I re-read your post and realized that your truck is staying engaged in 4wd....mine didn't do that. I have read that the actuators go bad also, but I'm not sure if that would affect the lights on the dash switch, sorry about that

-Billy

 

Sounds to me liek you got a grounding issue, very common its happened to me almost everything you said, check the grounds on the driver side cab mount for rust and corrosion