This is from Guyfang
Now when the gen set is cold, go around to the left side, and open the front door. In between the side of the gen set and the radiator, you SHOULD see a handle. When you push it down, it SHOULD spring right back up. The manual shutter control is what you have your hand on. Its supposed to work by itself. When you run the set, always close all doors. That way the gen set warms itself up right, and keeps itself cool enough. As the gen set reaches operation temp, (about 180) the loovers, (on the front of the set behind the grill) should open up. this way the set runs just right. Now these sets are kinda old. The loover control may not work right, or maybe adjusted wrong. There is also SUPPOSED to be a short rope with a hook on it to keep the loovers open, in case the control will not work right. That way you can continue to run, and not overheat the set. The loover control has bees wax in it to push a piston out, to open/close the control, regulating the engine temp. This is something you can check. Close it up, start it up, and read a book! Watch the loovers. Do they open up after a while?
The above is not a show stopper, but helps you get to know this beast, and insures less problems later.
Next, earlier you told us that you had no hertz and volts on the meters. I am assuming the gen set still is that way. You should not assume that in fact it has no volts. TEST. TEST. TEST. Because I am here to tell you, assuming will bite you in the patootie. So go to the left side of the set. Open the rear door. the CB2, (output contactor) is there in front of you. Remove the two covers from it. Start the set. Remember to hold S2 up a bit longer, 5-10 seconds. Set runs, and let it warm up a minuet or two. Close the S3, (AC out put switch) and see if the light comes on. If it doesn't, Flip up the S7, and when its light comes on, Try the S3 again. Light come on? If you still do not have Volts/Hertz on the meter, go back around to the CB2, and measure between the terminals. From one side to the other. AC volts. Do the front three terminals, then the rear three. Got voltage? If you do not have voltage front or rear, we can ASSUME that the main gen hasn't lit off, (been excited). No out put, so no load test. Yet.