Weller
Member
- 220
- 9
- 18
- Location
- Kern County, CA
Finished spring cleaning on my MEP-803A last week and now I'm having an issue with both the fuel level gauge and coolant temp gauge. Both were functional previously.
I'd done some heavy cleaning so may have pulled something loose. Cleaned out the box behind gauges with compressed air and had wet and wiped down areas near fuel level sensor and coolant temp sensor by hand.
While cleaning I noticed the electrical lead to the oil pressure sender was frayed, so I removed the lead, made a new terminal and reattached it. Oil pressure gauge is functional.
Photo shows unit while running.

Got out the manual. Disconnected batteries and checked fuel level sender first (didn't remove it). Disconnected, cleaned, and reconnected the wiring. Batteries reconnected.
I then disconnected the electrical lead from coolant temperature sender and measured resistance (was greater than 300 ohms). Measured again with set running and multimeter indication decreased. Cleaned the lead and washers and reconnected wire to sender.
Thought I'd ask before moving on to the next phase of troubleshooting.
I'd done some heavy cleaning so may have pulled something loose. Cleaned out the box behind gauges with compressed air and had wet and wiped down areas near fuel level sensor and coolant temp sensor by hand.
While cleaning I noticed the electrical lead to the oil pressure sender was frayed, so I removed the lead, made a new terminal and reattached it. Oil pressure gauge is functional.
Photo shows unit while running.

Got out the manual. Disconnected batteries and checked fuel level sender first (didn't remove it). Disconnected, cleaned, and reconnected the wiring. Batteries reconnected.
I then disconnected the electrical lead from coolant temperature sender and measured resistance (was greater than 300 ohms). Measured again with set running and multimeter indication decreased. Cleaned the lead and washers and reconnected wire to sender.
Thought I'd ask before moving on to the next phase of troubleshooting.