I have a 1979 l82 4 speed original # match etc. a problem that I recently experienced was when I turned my headlights on. When I turn them on, my temperature gauge light dims and the needle goes all the way to the right. Also, when this happens, the car sounds off a continuous high pitched "beeeeeep". When the problem first started to happen (yesterday night), it would correct itself after several minutes of the lights being on and go back to normal (happened twice). Now I (needing to test everything) turned them on during the day to see if the problem persisted, and it did, only this time it did not self-correct. Mechanical I'm alright but as for electrical I have no idea. Please help!

 

Battery gauge goes down when I turn the lights on. Its a short somewhere. Just got to find it.

 

Here's my $0.02. There's nothing easy about the electrical on these cars, especially under the dash. What your describing is some pretty serious Electrical Bizarro. You should already have at least the FSM or Factory Service Manual. Next would be the nicely laminated wire schematic, in the correct wire colors and if you're really electrically experienced, a multimeter.

Take it from me, you're going to be scrunched up underneath there, for hours. Very tight space and tough to even move your arms around, above you. I can't offer you any 'easy' solution, because you could have a short circuit, but is it to the other wires or is it to ground?

Did you install any bulbs recently? Because you'd be surprised that putting the wrong bulb in a socket, like a 1 post bulb, where a two post bulb goes, or vica versa, can have serious debilitating effects on your electrical system! We've seen it three times at our shop and the one '64 Corvette Coupe, we had in here, had a total wire harness fire and sat for decades, because someone put the wrong light bulb in the wrong socket on the overhead dome light!!!

You need to look for 'Bubba' repairs (because mine, had a million of them, to the point, I had to eventually just get a new dash harness). Bubba is the bozo that might've owned your car, before you and you can tell his repairs, from the wreckage he leaves behind.

Finally, I tell everyone, who's going to attempt to get into the Electrical and think they can handle analyzing what's going on. You'll save yourself many, many hours, spending the $100 or so and getting what the pro's would never do without, the Power Probe III. Do the video search and web search. Don't do, serious automotive electrical, without this.

Otherwise, you should bring it to an experienced Automotive Elecrician. Because you're a junior member, I don't know how much mechanical or electrical experience you have, but you should know, that pulling the dash boards on these cars is a very trying experience, count on it.