After successfully installing a new MSD ignition on my 78. The low fuel light now stays on constantly. I called MSD they said that the condenser that I installed on the brown wire on the alternater was installed upside down. I looked at it, it was installed correctly. Is there anyone that hashad this happen and how do I fix it?

What the heck would an ignition set-up have to do with the fuel light? Doesn't make any sense to me. If the MSD folks said the condenser was "upside down", could they explain why that would cause the problem? Did you change the condenser around to see if it made any difference? If you figure this one out, I'd be curious to know what the two had in common in order for the fuel light to stay on. Good luck; maybe someone here has the answer!

This is exactly what we thought. There is an adapter that I need to install to make my Tach operational. When I hook that up maybe the fuel light will mysteriously disappear. Also I think that the smaller wire going into the alternator may be a low voltage wire for the dash. But if that were true the rest of the dash would light up like a Mardi Gras float. Thanks for the feedback. I will let you know when I'm done with the Tach. Hopefully I won't create any more problems. As we all know the electrical systems in our Vettes are poorly designed and extremely  touchy.

Thank you very much Gary. I will replace the module this weekend. As you know wiring the tach adapter had nothing to do with the fuel light. The tach now works. Thanks again for the solution Gary.