In the bottom of the unit there are 2 slo blo fuses. 1 is a 10 and the other is a 20. Replace the 20 for the light. Replace the 10 for the vacuum. Make sure they are slo blow fuses.
If the above suggestions do not work check the followingSomeone gave me an AmerGraph 150 a few months ago. When I got it everything worked - vacuum, light... since then it's been sitting waiting for me to make my garage more workable. I've finally got everything set up and I can't get the vacuum to read any pressure and to boot when I press the light on button nothing happens. Does anyone have any experience with this unit that could help me troubleshoot? I'm coming from a ryonet unit that just has 3 switches so this is extremely confusing for me.