Okay, so my truck is a 2000 ram 3.9 auto single cab short bed 26 gal tank 126,036mi. About a month ago I went down to our trails climbed over one small hill, the next morning my gas gauge read a full tank when in reality I know I had a 1/4 tank. As soon as I got off my driveway it showed empty (steep driveway). This is what was really strange, about a mile down the road it started to read from full to empty to half etc. up and down over and over especially when taking off quick or stopping hard. Now within the past 2 weeks it reads on the needle stop below empty. It threw codes "P0462 Fuel level sensor circuit, low input" and "P0463 Fuel level sensor circuit, high input". I have checked the fuel system relay, checked the sending unit out of the tank for a broken float (which was fine), connected an ohm meter to the sending unit and for empty 220.6 ohms and full 20.5 ohms. Haynes manual says its supposed to be empty 110 ohms and full 10 ohms. Today I bought a Brand new sending unit from Dodge for 90 bucks and it reads the same ohms as the one in the truck. Also, if I reset the computer, no matter how much gas I have in it as soon as I turn on the ignition it goes straight to a full tank then slowly falls to the below empty point. I have run the gauge cluster self diagnostic too and no trouble there. Does anybody know if there are any other common problems with these things? Any help would be very much appreciated as I don't know how much gas is in it

 

Have you checked your cluster?

 

The gauges? yeah, I did the self diagnostic for the entire gauge cluster everything worked. maybe im missing something, or im looking in the wrong place

 

I don't know how accurate that self diagnostic really is, but you may want to take the cluster out and see if there are any loose connections, frayed wires, etc.

 

could be a ground but if the rest of your gauges work I'm thinking thats not likely

 

Looks like another one got bit by the faulty fuel sending unit.

 

I'd return the sending unit you nabbed and get another, might be bad out of the box. If that doesn't work, return it, and go get a different brand. I also wouldn't put it past a stealership to give you the wrong part that would have the wrong ohms, either.

When my 1995 Dakota's gauge did the exact same thing yours did, I had a local shop replace the sending unit. Cost me $200 total, parts and labor. Fixed the issue.

 

lol I just hope my dash doesnt crack anymore than it is when I pull that cluster, I will check that btw Ram1500 that could be the prob because of the non-existant dash over that area, sun could have gotten to it. Also I am going to return that new sending unit. I'll just bring up my ohm meter to the dealer with me to check the next one haha. Thank ya'll for the help, this site rocks!

 

You got a bad sending unit from the dealer. If you tested it when you got it home and it was outside the parameters listed for the appropriate ohms resistance then it was no good to start with unfortunately. Return that one and get another one and verify that it works right while you are there. the dealership is not the most honest place to deal with by any means.

 

Well tuns out the haynes manual was wrong, both new and old sending units were perfect. FSM helped me with that lol. I went ahead and put the new sending unit in. I have checked the wiring from the sending unit to the fuse box then from the fuse box to the computer. Haven't checked it to the gauge cluster yet. I'm thinking I might have a bad gauge cluster...