1986 Firebird starting problem

gc1566 · #1 01-31-2005, 09:06 PM

Hey everyone,
Im new here and this is my first post! I have a 1986 Firebird and Im having a problem starting it. I have a pretty heavy duty sound system in the car. Right now, it doesnt start up unless its jumped. Brand new battery. I can start it with a jump, leave it running for awhile, turn it off, then start it again. But if I leave it off for like a day, it needs to be jumped again. Even when I run it without the faceplate for the head unit in (which stops all power going to the amps for my subs and speakers) it still does the same thing. Anyone got any ideas? I would appreciate any help greatly.

Thanks,
Gideon

CreepingDeath94 · #2 01-31-2005, 10:42 PM

Well, sometimes the alternator can have an internal problem that will draw on the battery when the car is off and sits for a long period of time. Also, you might have some other draw like a glove box light or something that drains the battery over night. Check for draw in each circuit pulling fuses and see if any remove the draw...if there is one that is when you test it.

gc1566 · #3 01-31-2005, 10:48 PM

Is that a commen problem with 86 Firebird alternators? Im pretty sure its stock, but ill have to call the dude i bought it from to double check. Someone suggested to me that the alternator wasnt big enough to charge the battery at the rate it was being drained by my system, although the fact that it still dies even when the system is off is leading me to believe otherwise. Any ideas?

silver87ta · #4 02-01-2005, 06:56 AM

Pull the alternator and take it to Pepboys or Autozone (or whatever you have around you) and have it tested. Most of them will do it for free or for a nominal charge.

CreepingDeath94 · #5 02-01-2005, 09:59 AM

Just make sure that Autozone or Pep Boys can check the diode pattern of the alternator in their test. I wouldn't say its a common firebird problem but it does happen to most vehicles. I don't think its your system since it still died when you disconnected it, but I can't be positive from here. I would check for draw on the system first with the amp connected and then disconnected...and then check the rest of the car circuits for draw.

gc1566 · #6 02-01-2005, 04:46 PM

Sorta related question I think. I turn my system on, and I get hits from the subs, but nothing from my speakers. I checked all the RCAs, and they are all good. My 4 channel amp that I use for my speakers looks exactly like its working (i use a two channel amp for my subs, so im visually comparing it to that). I can tell you exactly when they stopped working. I turned on my car, my system was up real high so I muted it real quick, turned off my car, turned it back on later and they were dead. Any ideas?

pontiacpmpn · #7 02-01-2005, 06:32 PM

Quote:

Originally Posted by gc1566

Sorta related question I think. I turn my system on, and I get hits from the subs, but nothing from my speakers. I checked all the RCAs, and they are all good. My 4 channel amp that I use for my speakers looks exactly like its working (i use a two channel amp for my subs, so im visually comparing it to that). I can tell you exactly when they stopped working. I turned on my car, my system was up real high so I muted it real quick, turned off my car, turned it back on later and they were dead. Any ideas?

Dont know how much this will help solve you problem, but so it doesnt happen again. I have heard of a lot of people frying either thier battery or alternator by sucking too much current to thier system (if you headlights dim when you system is up its a good chance that is what happened) But it does sound like something is draining on it... to find out, unplug your battery when it is charged.. let is sit for a couple days, hook it back up, and see if your car starts.. if not.. go buy a new battery.. If it does... id take the advice from other users.. It happened to a freind of mine, he went through like 3 alternators and batteries or something like that.. anyway go out and spend about 100 bucks on a Capacitor for you system, it charges with a much smaller current, and stores power in it so it isnt pullin on your alternator... you can look up wiring schematics online on how to wire a capacitor into your system, but it should come with them (just dont touch the terminals when its charged... 1 farad is a lot of power...). As far as your your speakers not working... you may have popped a fuse or something in your amp or whatever your amp gets power from, used to happen to me all the time. If that doesnt solve your problem, try hooking up your speakers' amp to your subs, just to test it and make sure the amp isnt cooked... Also check the wiring harness on the back of your deck to be sure it is fitted properly.

gc1566 · #8 02-01-2005, 10:03 PM

Well, I do have a cap, and the wiring on the cap is all correct. Ugh, frustrating

pontiacpmpn · #9 02-02-2005, 08:30 AM

Quote:

Originally Posted by gc1566

Well, I do have a cap, and the wiring on the cap is all correct. Ugh, frustrating

yea car audio gets frustrating easy...
That is strange... I dont really know what else to tell you other than just rewire your system to get the speakers to work... check ALL connections having to do with the speakers, and any fuses, and then if you still dont find the problem the only thing else to do is either rewire the entire system, or bring it somewhere like audio king or best buy to see if they can figure out whats up with it... I dont think it costs too much if anything.. i mean my freind had his entire system installed at best buy for 150 bucks.. so it cant be that bad... As far as the starting problem, like everyone else said it sounds like a slow leak.. no new ideas there... good luck though

CreepingDeath94 · #10 02-02-2005, 11:10 AM

The only problem with Best Buy and Circuit City is they don't exactly do professional wiring jobs. I've seen wires twisted together and electrical taped from those places so be careful.

hotrod_chevyz · #11 02-02-2005, 06:33 PM

unplug all the stereo and amp fuses,get the car started and let it run ten minutes with all the stereo equipment unhooked.Shut it off after 10-15 minutes.Unhook any power wires from the battery posts.Check the exact battery voltage with a voltmeter.You shoud get a reading like 12.35,or such.check it the next day with the same meter and see if the battery has lost any power with the battery unhooked all night.If it does then the problem is your battery.
The capacitor could be draining you voltage.You may have to run a relay such as a ford starter relay,to take the capaciter offline while the car is off.capacitors store voltage,and in your case might be sucking the power right out of your battery.

A volt meter can also check the voltage at the battery,while the engine is on.You should get a 13.8-14.2 volt signal at the battery,engine running.

volt meter=20 bucks at radio shack

If you dont have 20 bucks,or if this sounds intimidating to do,then just unhook the + side of your battery,and tap the battery post against the proper terminal,and if you get sparks,then you have a power draw somwhere.You can unhook equipment or pull fuses,until you dont see sparks when you tap the post to the terminal.once you unhook somthing or pull a fuse,and it stops the sparks at the battery post,you have fount the culprit.

CreepingDeath94 · #12 02-02-2005, 08:09 PM

Not trying to down play Hotrod's suggestion, but I would spend the $20 on the proper tool. You run the risk of spiking the computer or various sensors if you just disconnect and reconnect the battery allowing it to spark, especially if you keep doing it to find the problem.

hotrod_chevyz · #13 02-02-2005, 08:25 PM

okay i might be wrong on this one but if the ignition is off your pretty much safe on that one the ecm has like three 30 amp fuses its not all that sensative and when you turn off the ignition it kills the power to the ignition module and fuel system relays,therby turning off most sensors

If the computer is always connected to the battery,that would be a power draw in itself.Thats why they have a preset codes stored in memory inside the computer,because it powers down with a click of the ignition switch.

You can have a custom wound alternator,wich will put out more amps.call a local alternator shop and ask for details on high output alternators.

If your stereo and amps arent wired right,it can cause damage to sensors and other electrical stuff,cause when your stereo basses hard and you have a big amp,the voltage at the battery somtimes can reach 8 volts in some cases.Mine goes down to 11.5 when it hits the twelves.

CreepingDeath94 · #14 02-02-2005, 10:14 PM

You probably know more about the firebirds than I do, I was just taught not to do that...especially on the newer cars.

hotrod_chevyz · #15 02-02-2005, 10:23 PM

of course if unhooking your battery resets codes,then i guess it has constant power to the computer at least one wire.I never thought it any danger checking the post for a power draw tho.its theoretically possible to damage the memory circuit of the computer tho your right.usually its older cars that pull in with the voltage power leaks.

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