1999 Chevy S-10

Typical chevy problem floating Guage ,u can try Taking a rubber mallet hit underbody of tank may unstick ur float in the tank , you can also go by your mileage vs gallons put in tank at tine of fill up 10 gallons drive 120 miles get more gas keep reset ur ode meter ,or replace float in ur tank

There may be a blown fuse causing the trip meter failure and quite possibly the gauge reading failure. since you didnt say if they went out at the same same it is hard to say but checking the fuses is a likely culprit for the first problem. it is entirely possibly that you fuel guage just stopped sending the signal up to your guage. this is known to happen usually only remedied by replacing the fuel pump as it is part of the wiring on the pump itself. that is unless that fuse is the reason it is bad. the other thing is the possibility of a broken/shorted wire that provides the signal from the pump to the guage good luck

that would be a wet soak concern, Likely fuel pump failure

im not an expert but my chevy s-10s fuel gauge didnt work for like a year! and my fuel pump just went like a month ago replaced it and voila i have a fuel gauge again!

it has a different ohm rating than the factory one instead causing this reading
the factory guage will read 8 ohms when full

Have you replaced the fuel filter, spark plugs and wires? A plugged fuel filter will cause a fuel pump to go bad because it works harder to pump. It also may cause less pressure. Plugs, wires cap and rotor will cause lack of power and fail you on a load if they haven't been replaced for a while.

the vent in the gas tank must be plugged have evap system serviced.

GM vehicles ,especially trucks it seems have alot of problems with their fuel guage sending units. The sending unit is the most likely reason but it can still be wiring or the guage itself.
Does it function at anytime or is it inoperable all the time ?
Most of the time (but not always) when a sending unit is not working properly it is usually when you have a certain amount of fuel in the tank and when it gets to that level it dont function but any level above or below that level it functions.
If this is your case then I feel comfortable in saying it is the sending unit. If not you need to do further testing to be sure it isn't wiring or a guage problem.
And no this is not a indication that your fuel pump is getting ready to go out. Your best protection to keep that from happening though is regular replacement of your fuel filter.
I hope this helps.

the 100% for sure cause of this problem is the sending unit for the fuel guage, it is located in the gas tank. U may have to replace the fuel pump module to get the sending unit, as a rule they are one piece, if u have over 100,000 miles that is a good idea anyway.

The float that helps detect fuel level is most likely broken. You or a mechanic will have to remove the fuel pump from the gas tank and check and possibly replace the float. Merry Christmas.