I have a 1991 lariat f150 4.9l 5 speed manual 4x4 that has probably been through a lot in its life judging by its body and it has its issues but runs down the road good and for 300 I just couldn't turn it down, now the gauge issues are the battery gauge read in the middle or higher but yet the battery light is always on and charges at the battery during idle around 14.3 volts then when you bump the throttle up it goes to 14.5, next is the speedo always reads about 35mph, I notice the cable was pulled out of the sensor in the tcase but wouldn't it go back to zero? And the worst thing is the fuel gauges are faulty on both tanks, front tank always reads empty and rear always reads full and sometimes bounces around , front always read empty, any ideas on the guage issues? Thanks in advance!

 

Now Im guessing and going by memory on these so....may not be correct.

The battery light issue is most likely the green and red wire if I remember correctly, "Guessing and going by memory." Goes from the alternator to the dash. -OR- its the alternator.

The reason your front tank reads empty is because your float inside your gas tank probably has a hole in it and its filled with gas or it fell off.

"The front and rear tank issues may be in reverse order."

The reason your rear tank reads like that is because you have a ground wire issue going to your tank. It causing the needle to peg out. Check the wiring harness plugging into the tank.

If you pull codes it might tell you open ground on gas tank if I'm correct.