Start the set. Then measure from ground to first one, and then the other contact on the FU1. (Open the control panel door. FU1 is right in front of you. It has two places to soldier wires to it. Set your DMM to DC volts. find a good ground point in the control panel. Touch it with one DMM probe and use the other to touch first one wire connection, then the other. You should get 24 VDC at both places) You should get 24 VDC. (Turn off the set) Then check J6/P6 canon plug to make sure its tight. (Open the two doors on the rear of the gen set. go down on your knees and look at the bottom of the control panel. There you will find the canon plugs there. one of them is J&/P6. Unscrew it and look at the plug. Is it ok? Not dirty, not melted, not corroded? If its good, then lay down on your back and move your head into the set and look at the other side of the cannon plug. Inspect it for the same things you just looked at. Use a good flashlight) Also unscrew it and look at both sides of the plug. Yes, its a PITA to look at the side on the bottom of the control panel. But you want to make sure there is no damage to the pin, or some kind of corrosion.
Better?