B737-700
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 287; Flight Crew Type 6000
Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance; Inflight Event / Encounter Fuel Issue
General Flight Cancelled / Delayed; General Maintenance Action
Aircraft; MEL; Procedure
Our aircraft arrived from ZZZ with an MEL for the #2 fuel tank quantity gauge reading 530 lbs. low. We read through the MEL to verify which procedures we would be required to complete; mainly the dipstick of the #2 tank to verify fuel quantity. I took for granted that the other procedures required were completed correctly by Maintenance. I didn't even realize that it was Contract Maintenance in ZZZ that completed the procedures for the MEL. Maintenance in ZZZ disconnected the center fuel tank gauge in error; instead of the #2 fuel tank gauge; as required by the MEL. We observed no reading at the center tank gauge and incorrectly assumed that there was no fuel in the center tank. On our second leg from ZZZ to ZZZ1; we realized that the center tank should at least read a zero and not blank and decided to have Maintenance meet us in ZZZ1 to correct the problem.
B737 Captain reported that maintenance did not comply with MEL procedures resulting in fuel tank quantity gauge reading errors.