[mustangsoldier]

ok so i swapped out to the 3g alternator bout two months ago and haven't had any issues at all. then last week i went to start my car after it sat for the weekend and thought the battery was dead but it finally started. well monday i had the same issue but this time it didn't start. i drove the wifey's van so far this week and just went out and opened the door and no lights or anything. i jumped the car and drove it around, no issues, even sat at idle and my voltage meter showed it was good. then i turned off the car and try to start it again and got nothing! WTF someone please help me ASAP im about to lose my damn mind.

[baine21225]

sounds like you have a grounding/drawing issue

[mustangsoldier]

but if it was that then why was it good to go for so long?

[baine21225]

maybe a wire moved and moved back? i have no idea?

[BostonPerformance]

how are your battery terminals and is there any corrosion on your neg battery cable? also get a voltmeter and make sure that there's no shorts anywhere.

[1fst5.0]

sounds like a ground problem, check ur connections

[superbean]

check your ground wires.

Also do a wiggle test... sounds like something is grounding in your harness somewhere. But having the car running, move the wires around and monitor voltage readings.

Or start pulling fuses and check for amperage draw (.....zzzzzzzzzz..... lol)

[84gtman]

hey did anyone ever solve this problem. i ask cause im having a similar problem. my 84 mustang will start fine then i turn it off and try to turn it back on it wont start. same issue as the guy who posted this thread i go back a couple of hours later and it turns on like nothing. wtf...

[93lxvert]

I had the same problem twice. First last month it wouldn't start until I jumped it off, then it ran fine. I even took the battery to my local parts store to have them check it and it checked fine after charging. I would get it home, shut the car off and the next morning it would do the same thing. Bought a new battery and the car ran fine for awhile. All of a sudden it started the same thing again eventually the alt. wouldn't put out more than 12 volts. Then one night after jumping it off again, I put it in reverse just to get it out of the driveway the altenator started smoking and the car immediatly died. I swapped for a 3g alt last week. Car is running fine so far

[nolife]

Originally Posted by 84gtman hey did anyone ever solve this problem. i ask cause im having a similar problem. my 84 mustang will start fine then i turn it off and try to turn it back on it wont start. same issue as the guy who posted this thread i go back a couple of hours later and it turns on like nothing. wtf...

I'm confused by your symptoms, you said it will start fine but a couple hours later it will not start fine? At what point does it start fine again? Or when you say a couple hours later "it turns on like nothing" do you mean it starts with no problem like nothing was wrong or nothing at all works and every thing is dead?

Go out in the morning and car won't start.
This is caused by the battery not being able to supply enough current to start the car.

A) Measure the voltage at the battery posts and write that down for later.

a1) If the voltage is at least 12-12.5v and the car is not starting, the terminals/wires are bad or the starter is going bad (internal starter wiring breaks down over time. An older starter can require A LOT of current and even more when they are hot). Check and clean the terminals and verify the wires are good and attached with a clean connection at the other end as well (starting solenoid and frame)

a2) If the voltage is less then 12v, you have to find out why. Is the alternator not putting out enough current and not charging the battery, is there a short somewhere draining your battery after you shut off the car, or is the battery simply not holding a charge.

B) Get the car running. Measure the voltage at the battery when the car is running. Is it at least 13v-13.5v at about 2000rpm?

b1) If it is at least 13v then the alternator is working, your problem is the battery or the battery wiring, or a short somewhere

Is it a short somewhere? Let the car run for a while and let the battery charge. Shut off the car and measure the voltage. See if it starts right back up. If the next morning, the voltage dropped more than a volt or so, or it won't start, you have something draining your battery. Next time you park the car after driving it, disconnect the battery and see if it starts in the morning.
What does the voltage gauge in the dash look like with the flashers on at idle, does it swing around a lot in sequence with the lights?

b2) If it is not at least 13v, your alternator is bad or its wiring is bad. Alternator wiring is not usually "going bad" for long, once it starts going bad, it usually burns up soon after.

Note on a hot or worn starter. If the car starts fine in the morning but has a hard time starting like when you are done pumping gas, it is either the starter going bad or a combination of a weak battery and a bad starter. If your battery is weak and you have an old starter, you have two problems. A weak battery can turn a new or cold starter and a new battery can turn an old and hot worn starter. Example being, you can have a hard time starting a hot car which could put stress on an old battery, the wiring, and connections so you buy a new battery. As the starter gets worse, even the new battery will not be able to start it.

With the combination above, you should be able to narrow it down. A bad cable or ground can cause weird problems or a combination of things and so can a partially working voltage regulator. Most national car parts chains will check a battery and alternator for free. They are not 100% accurate but worth a try.

[95StangMX]

just a note: when checking a battery, using a voltmeter doesnt always work, a bad battery or a battery with a dead cell will sometimes show 12-13.5 volts but when you put a load on it, it will drop. I have a special meter that pulls a load while checking the voltage, I think most auto stores will check them for you with a load tester.

[Lind]

id take it to autozone a get a test done on the alt

[1Fast93GT]

check your starter wires and make sure it did'nt get burnt by your hearders or if your starter is getting hot?? no clue other than this...

[84gtman]

alright i think i have the solution to your problem i had the same issue with my 84 gt i was going crazy trying to figure out the problem its prob not the alt its the power regulator inside of it if you go get it checked they cant do a complete check the can only check if its charging not how its regulation the charge so they can tell you everything about the alt. my power regulator is out side the alt like a little silver box but i think yours is inside the alt if not check around the side by the battery...