Update: finally got some time with a forum buddy
to help me diagnose the problem.
The bike had not been ridden since the DGR and coolant overflow issue.
Upon removing the tank we noticed that the cap off the extra coolant reservoir was off. I know I had shut that properly the last time so itís obvious that happened due to pressure from the coolant expansion reservoir.
We swapped out the fan switch, checked that the temp light works and also checked the thermostat in a pot of hot water. Everything seems to work fine.
We concluded that it might just be an air bubble in the radiator.
We filled up the radiator, let it run, rocked it side to side, then tried to squeeze all hoses to get air out. We noticed a very small amount of bubbles from the radiator bleed screw. We took the bleed screw off completely to see if more coolant come out trying to eliminate all air inside. Even with the bleed screw off no coolant was gushing out until we loosened the radiator cap and took it off for a second there was like a fountain of coolant from the bleed screw area. I guess the air was trapped in there somehow.
We finally topped up the radiator and closed off the bleed screw. The only test that we have not done is to replace the temp sensor. I ask because the temp light never came in when the coolant heated up and overflowed.
said it could be possible that due to the air pocket the coolant was just stationary and heating up. The engine may not have reached the required temperature for the temp light to come on.
Any other suggestions from the great crew here. Rode the bike back home few miles but no fan came on. Is there a way to check when the fan should be coming on.
2015 BMW F700gs
2000 triumph thunderbird sport