Some reason my car died over night. I made a topic about this before, because my battery amp light came on a few times, but went out, sometimes it stayed on, but other times it blinked. Anyways today it finally told me I should have payed attention to it, because the car was completely dead. It was running fine last night, that warning light didn't come on once. Now the dome light doesn't work, nothing on it works. I was thinking it might be the alternator, but that just charges battery when the engine is running so what else could have caused this? I was pretty sure all the lights inside were off, I'm thinking maybe the glove box light was on or doesn't go off when the little door is closed?
Mercury Grand Marquis 1986. Battery is only a year old.
2007-10-01 15:51:27 · 4 answers · asked by hatchetmind85 1 in Cars & Transportation ➔ Maintenance & Repairs
Sounds to me like a bad alternator. There are 6 diodes in a 3 phase circuit that actually take the high frequency a/c power and do the charging.
If one of the diodes shorts out or leaks, it will kill the battery.
I suggest charging the battery with the wire off the alternator, a letting it set that way for a day. Then try the lights etc. If the battery remains charged, the alternator is bad.
No, I don't mean you can use the vehicle.................
2007-10-01 15:59:42 · answer #1 · answered by Wisdom 6 · 0⤊ 0⤋
You are barking up the wrong tree !! I would guess you have a charging system problem. The light blinking is telling you you have a problem. It may be a loose connection or dirty battery terminals. Get a battery brush at auto supply and clean the battery terminals and posts till they shine. You will need a volt meter to check your alternator output. Auto supply will usually do this for free. Get it done on the car. The alternator output should be close to 15 volts. A reading across the battery terminals should read same as alternator output. A fully charged battery will read 13.5 volts with engine off. Get battery checked age means little they can fail at any time.
2007-10-01 23:09:07 · answer #2 · answered by tronary 7 · 0⤊ 0⤋
That blinking you saw was the equivalent of the last dying screams of your alternator diode. The alternator wasn't charging, but the battery had enough juice to carry you for a while, but without having the alternator to recharge the battery, it also died a slow torturous death. Battery should be ok after a recharge, but sounds like the alternator is bad.
2007-10-01 23:17:02 · answer #3 · answered by Anonymous · 0⤊ 0⤋
the alt can drain a battery if the diodes in side short out. have the alt. and regulator tested this should take care of it
2007-10-01 22:57:30 · answer #4 · answered by twandrews mechanic 20 years 2 · 2⤊ 0⤋