Battery issue 2007 GT
12/3/16, 05:28 AM
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Battery issue 2007 GT
OK, Before I go on wild goose chase... Have 2007 GT, been running fine then last night I started & was fine. Had radio on & lights, suddenly radio shut off & displayed LOW BATTERY warning. Looked at gauge & it showed LOW charge. Turned off lights & gauge raised a little. Turn lights on they were dim & gauge dropped again. Pulled ☝ to red light & kept revving up engine (to make it 2 house)..light changes & hit gas pedal, suddenly the lights became brighter..radio came back on & gauge was fine..showed normal charge.
Any clues as to why it would drop like that then suddenly correct itself? Taking BATTERY for test this morning first, have feeling this is going to be difficult to locate issue if not BATTERY..any help?
Any clues as to why it would drop like that then suddenly correct itself? Taking BATTERY for test this morning first, have feeling this is going to be difficult to locate issue if not BATTERY..any help?
12/3/16, 08:38 AM
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Battery issue
I pulled BATTERY out & got tested...has 11.99v but only showed 21% charge. Battery only 8 months old..I'll check terminals & clean them. I would think alternator, but that sudden burst to correct makes me wonder...
12/3/16, 10:06 PM
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Check here:
https://themustangsource.com/forums/...458833/index4/
Post number 70. This explains the entire situation that has seemed to keep my electrical system from having issues.
Short version: Disassemble the entire battery tray area. Clean *thoroughly* with that yellow/pink stuff until no more pink as prescribed, all pieces. Be meticulous and (that word associated with yer bum, but means being real particular) about it. Reassemble tray, battery, put on washers on the terminal posts, slather bottoms of terminals with dielectric grease, put terminals on, slather terminals with that grease, button up, done.
Best with a newish battery that's not Motorcrap, and also a freshish alternator. I *highly recommend* that if you have to get an alternator, you get a *lifetime warranty* one so that if it craps out you can get another quick and easy, and also not couple a bad alt with a new battery, or old battery with new alt, as they tend to cycle themselves bad if that's the case. Plus, I had a *clutch* go out in my last one I replaced. Yes, they have clutches. I didn't know until then either. Free swap. So sweet.
When you put on the new alt, dielectric grease on them connectors after any cleaning needed.
I am not saying I've solved it... but it would seem that I solved it. So far, all these years and miles later since I did all that mess... no issues (save that weird clutch issue, which was pretty early on after that process), battery and alt are goin' strong. Not that I wanna jinx it, but it was pretty irritating before, now she just runs. So I hope that continues.
Anyway, hope that helps ya!
https://themustangsource.com/forums/...458833/index4/
Post number 70. This explains the entire situation that has seemed to keep my electrical system from having issues.
Short version: Disassemble the entire battery tray area. Clean *thoroughly* with that yellow/pink stuff until no more pink as prescribed, all pieces. Be meticulous and (that word associated with yer bum, but means being real particular) about it. Reassemble tray, battery, put on washers on the terminal posts, slather bottoms of terminals with dielectric grease, put terminals on, slather terminals with that grease, button up, done.
Best with a newish battery that's not Motorcrap, and also a freshish alternator. I *highly recommend* that if you have to get an alternator, you get a *lifetime warranty* one so that if it craps out you can get another quick and easy, and also not couple a bad alt with a new battery, or old battery with new alt, as they tend to cycle themselves bad if that's the case. Plus, I had a *clutch* go out in my last one I replaced. Yes, they have clutches. I didn't know until then either. Free swap. So sweet.
When you put on the new alt, dielectric grease on them connectors after any cleaning needed.
I am not saying I've solved it... but it would seem that I solved it. So far, all these years and miles later since I did all that mess... no issues (save that weird clutch issue, which was pretty early on after that process), battery and alt are goin' strong. Not that I wanna jinx it, but it was pretty irritating before, now she just runs. So I hope that continues.
Anyway, hope that helps ya!
12/4/16, 03:24 PM
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I took the alternator out & took to have bench tested. It was the alternator after all. Was only outputting 8.5v so was bad. Still doesnt explain the sudden correction issue though.
Check here:
https://themustangsource.com/forums/...458833/index4/
Post number 70. This explains the entire situation that has seemed to keep my electrical system from having issues.
Short version: Disassemble the entire battery tray area. Clean *thoroughly* with that yellow/pink stuff until no more pink as prescribed, all pieces. Be meticulous and (that word associated with yer bum, but means being real particular) about it. Reassemble tray, battery, put on washers on the terminal posts, slather bottoms of terminals with dielectric grease, put terminals on, slather terminals with that grease, button up, done.
Best with a newish battery that's not Motorcrap, and also a freshish alternator. I *highly recommend* that if you have to get an alternator, you get a *lifetime warranty* one so that if it craps out you can get another quick and easy, and also not couple a bad alt with a new battery, or old battery with new alt, as they tend to cycle themselves bad if that's the case. Plus, I had a *clutch* go out in my last one I replaced. Yes, they have clutches. I didn't know until then either. Free swap. So sweet.
When you put on the new alt, dielectric grease on them connectors after any cleaning needed.
I am not saying I've solved it... but it would seem that I solved it. So far, all these years and miles later since I did all that mess... no issues (save that weird clutch issue, which was pretty early on after that process), battery and alt are goin' strong. Not that I wanna jinx it, but it was pretty irritating before, now she just runs. So I hope that continues.
Anyway, hope that helps ya!
https://themustangsource.com/forums/...458833/index4/
Post number 70. This explains the entire situation that has seemed to keep my electrical system from having issues.
Short version: Disassemble the entire battery tray area. Clean *thoroughly* with that yellow/pink stuff until no more pink as prescribed, all pieces. Be meticulous and (that word associated with yer bum, but means being real particular) about it. Reassemble tray, battery, put on washers on the terminal posts, slather bottoms of terminals with dielectric grease, put terminals on, slather terminals with that grease, button up, done.
Best with a newish battery that's not Motorcrap, and also a freshish alternator. I *highly recommend* that if you have to get an alternator, you get a *lifetime warranty* one so that if it craps out you can get another quick and easy, and also not couple a bad alt with a new battery, or old battery with new alt, as they tend to cycle themselves bad if that's the case. Plus, I had a *clutch* go out in my last one I replaced. Yes, they have clutches. I didn't know until then either. Free swap. So sweet.
When you put on the new alt, dielectric grease on them connectors after any cleaning needed.
I am not saying I've solved it... but it would seem that I solved it. So far, all these years and miles later since I did all that mess... no issues (save that weird clutch issue, which was pretty early on after that process), battery and alt are goin' strong. Not that I wanna jinx it, but it was pretty irritating before, now she just runs. So I hope that continues.
Anyway, hope that helps ya!
12/4/16, 03:39 PM
#6
GT Member
Do you have a multi-meter? If not get one, [ I prefer digitals ] they're cheap and a very useful tool to have both in the house and the garage. With the engine off set the meter to volts-DC and connect the negative lead from the meter to the negative battery post and the positive lead to the positive post. You should have just a bit over 12 volts. With the engine running connect the leads as before and you should have anywhere between low 13 to low 14 volts. If it's less than 13 volts you have problems with charging the battery. Dirty/loose leads if your lucky, bad alternator if you're not.
12/7/16, 06:24 PM
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Found the issue with battery light & check charging system (took all day though). After running every test, placing multimeter on ever possible electrical connection, FINALLY found the culprit. The pigtail on the cable from battery to alternator was bad, where it plugs in alternator. Have to replace wiring harness between battery & alternator.