AAX86

I've barely been able to take out my '86 in the past few months but i've taken it out a few times this week since it got running. I've been taking it out at night and i noticed some weird problems with it. It has an idle surge like a lot of stangs out there, but that's not the problem. The problem is, i noticed every time it surges, everything electrical surges with it. For example, when the idle is high, the headlights and gauge lights are bright like normal. And when the idle drops, the lights dim down really low. Even when it's running at 40+mph i notice the headlights surge bright then dimmer.

Any idea what's wrong with it or what i could try?

Car's a mostly stock '86 with a '90 5.0 in it. Only mods are a cai, ford racing starter, and complete exhaust with the exception of the stock h-pipe on it right now to smog.

mattdel

Alternator output drops when engine RPM drops. 2 choices: deal with it, or do a 3G conversion. Fixing the idle(vacuum leak is most likely for a stored vehicle) will likely not fix the voltage issue, as it will get worse with time.