Hello! This if the first post on this forum and I am glad to be here! I recently was passed down a 1987 Firebird Formula 305 TPI from my father with 19k miles on it. I am trying to find some information on this issue I have been having. I usually start the car up maybe once or twice a month since its cold out and needs some work at the moment to be roadworthy. I plan on getting it running in the next few weeks when it gets warmer out.

If I leave a fully charged brand new battery connected to the car overnight, it will usually be dead or almost dead the next day. The previous owner and my dad didn't really have any issues with the parasitic drain till a few years after my dad purchased the car. The previous owner before my father put an aftermarket alarm system in the car while it sat outside of his apartment complex. I think it may have something to do with the UNGO Box which I see is installed. I noticed that there is a little button that I can press and depress kind of under the rear of the shift boot. I think that may be a switch to disable to enable the alarm system. Not sure though. I was debating on taking that shift boot off and seeing what kind of wiring is going on underneath there. The next thing I noticed is that there was a terminal lead which was used when plugging in the battery. You could tell that it is something non oem and I think not having that being attached while the battery is plugged in may help with the issue. You can really see that there was an aftermarket system with the plungers under the hood which were wired for that system. It would be a cool nostalgia piece but I think I want to remove it all. I saw a few posts on people here who have removed the box and I will attempt to locate them but I feel like that may be one main issue right there. I am going to try the parasitic draw test and see what we get out of that. I need to try keeping the car plugged in with the aftermarket lead disconnected and see if that helps.

The other issue is that the car will sometimes not want to start. If you have a BRAND new battery, usually the car will start right up with no issues. Now the battery is older, I usually just use a jump pack and let it run a little bit once I get it running. We would have an issue (even while out driving it) where we could park the car, leave it sit, and then come back to nothing when you turn the key. Then you wait a few minutes and the car will start right up. My dad says it may be a starter short but is there anything else I should check? Thank you all so much and I am excited to learn more about this car!

 

Basic troubleshooting steps, as outlined in the car's factory shop manual, will find the problem---unless it's being caused by that aftermarket alarm system. If it were my car, the first thing I'd do is get rid of that alarm and restore the car's wiring back to stock; that in itself may correct your problem. If not, you'll at least now have a baseline from which to start searching.

 

I'll second the "ditch the alarm" sentiment.

And Welcome Aboard!