Fuel and Temp gauge

The spade connectors on the limiter are very substantial by comparison because they support the weight of the limiter. The female connectors used are only snapped in so they absorb or dissipate vibration/shock. A loose connection here, due to age and/or corrosion has been the fault found.
Some have added gobs of solder where these females terminals meet the circuit board. I don't know if that's a good plan.
If you buy a solids state regulator with ring terminals, a #6 X 3/8 screw with toothed washer can be used to make a secure connection in those female connectors.