98 C280 gas gage erratic, now what?

[cgshawaii]

Hello all... the wife's gas gage is on the fritz. '98 C280, 140kmiles. Key on, engine on or off, the gas gage needle pegs to the left against the center of the temp gage. At the same time, the low fuel light comes on. Sometimes the gage needle will wander erratically, but the low fuel light stays mostly on. Or turns off, no correlation to needle behavior.

Gage started this behavior after I disconnected the battery overnight. Coincidence or ****to luck?

Did some searching on this forum and found that the tank is a saddle type with siphon between two sides, pump and filler on right. There are two senders in series, perhaps one or both are bad. And they're not cheap.

How do I access the senders, or their connection to ohm-test them? I removed the trunk floor panel between the rear wheels, and see three two-wire connectors mounted in the plastic that sits on body metal. Which to of these three are to the senders, and what should the sender ohms reading be if the tank is full or nearly so.

Wife will have to get along with the tripmeter rather than gas gage in the meantime.

All suggestions welcomed; this forum seems a wealth of info.