lights dim till 3k RPMs, then fine.

[Blank-Disk]

When I turn on my 93 ATX, all the lights are dim, even the clock. They stay that way till I rev the engine, or I get going and hit about 3k RPMs. After that they're fine, and don't dim out unless I'm at low idle. What would this point to?

 

[Ishodu]

A failing Alt. Check the voltage when at idle. See what your getting.