My fuel tank gauge on my Yamaha Command Link system shows a full tank all the time.  It was just working the other day at the gas station but when I took her out this weekend first noticed it wasn't registering my actual gas tank level.  I know I don't even have close to a full tank.  
Does anyone have any troubleshooting tactics to determine if it is indeed a bad sending unit or just perhaps an electrical or grounding issue?
Thank you for your help.
	
		
			
		
		
	
				
			Does anyone have any troubleshooting tactics to determine if it is indeed a bad sending unit or just perhaps an electrical or grounding issue?
Thank you for your help.