Petrol Gauge

[cortez]

Did some work on boat today (thermostat)on volvo 5.7dp 1993. When i come to start engine to check for leaks i here a very loud crack or short i then had no power from batt no1,I could see nothing amiss so turned switch to batt no2 no problems at all put switch to no1 all fine all power restored apart from petrol gauge.It now goes all the way over to empty as if shorted out<br />somewhere, can any one give me a clue as to where i might start looking, and how can i check the gauge.<br /> Thanks in advance

 

[ricksrster]

Re: Petrol Gauge

It sounds like you shorted, tripped a breaker, and burnt out a wire. check the wiring at the gauge for burnt or melted insulation. Check the wiring the rest of the way back to the sending unit on the fuel ( petro to you guys ) tank. If the wires don't look burnt, remove the sending unit. Use an OHM meter to check by hooking the leads from the meter to the terminals on the sending unit. Move the sending unit float up and down. the change in resistance should rise and fall smoothly. If the sender is fine, test the gauge. Disconnect the + sender/signal wire from the gauge. Sometimes this is a pink wire. Hook a positive from the battery to the sender signal post. The gauge should read full, disconnected empty. OH YES, CHECK FOR A FUSE. If the fuse is blown the above checks should find the cause. If the gauge and the sender both check good, Repalce the wiring and add a fuse if one isn't already installed.