Battery is always running down
Thread Starter
Drifting
Joined: Sep 1999
Posts: 1,439
Likes: 1
From: Hagerstown MD
Battery is always running down
Last Saturday, I drove the Orange Shark around town. Started it maybe 4 times. When it came time to start it for a 5th time, nothing happened... I had to jump start the car. I did notice that when I was driving home, the alternator light on the dash would glow ever so dimly whenever I turned on my high beams. (This is with the stereo turned off.)
My car is electrically stock except for the following items:
1. Aftermarket stereo; head unit and two amps. Head unit switches amps off, or so I'm 99 percent sure. Will check this.
2. Aftermarket electric choke on Q-jet carburetor.
Alternator is a cheap replacement unit that is several years old. Battery is a few years old but I try to keep it charged when I'm not driving the car.
Where should I start in debugging this electrical problem?
My car is electrically stock except for the following items:
1. Aftermarket stereo; head unit and two amps. Head unit switches amps off, or so I'm 99 percent sure. Will check this.
2. Aftermarket electric choke on Q-jet carburetor.
Alternator is a cheap replacement unit that is several years old. Battery is a few years old but I try to keep it charged when I'm not driving the car.
Where should I start in debugging this electrical problem?
Drifting
Joined: Nov 2002
Posts: 1,665
Likes: 1
From: Ontario
Probably the best thing to do first is to take your battery into your local auto parts store, they'll generally test it for free.
What does your voltmeter read with the engine running? Ideally it should be 14.5V. Anything over 12V will charge the battery.
If your alt is putting out good voltage then its a good chance your battery is the problem. If your alt is putting out less than 12V it could be bad or it could be a bad battery pulling the voltage down. Either way the battery is the best place to start.
What does your voltmeter read with the engine running? Ideally it should be 14.5V. Anything over 12V will charge the battery.
If your alt is putting out good voltage then its a good chance your battery is the problem. If your alt is putting out less than 12V it could be bad or it could be a bad battery pulling the voltage down. Either way the battery is the best place to start.
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
they can tshoot the alternator for you on the car and if it is good they can do a load test on your battery also. the alternator may still be under warranty.
do you have a battery disconnect installed? if not, whilie you are there you could pick one up. i use mine to disconnect the neg cable each time i turn the car off.
good luck, let us know what you find.
Thread Starter
Drifting
Joined: Sep 1999
Posts: 1,439
Likes: 1
From: Hagerstown MD
Fusible link... hmmm, I never thought of that. I'll add that to the list of things to check.
A fella at work here who has been building cars since before I was born says to run the engine at about 1000 rpm, turn on the headlights and the blower fan, and see what kind of voltage is indicated. If it's not 13+ under load (yeah, I know the in-dash gauge ain't the most accurate), that indicates a problem with the charging system.
A fella at work here who has been building cars since before I was born says to run the engine at about 1000 rpm, turn on the headlights and the blower fan, and see what kind of voltage is indicated. If it's not 13+ under load (yeah, I know the in-dash gauge ain't the most accurate), that indicates a problem with the charging system.
Thread Starter
Drifting
Joined: Sep 1999
Posts: 1,439
Likes: 1
From: Hagerstown MD
It wasn't the alternator... I took it to Advance Auto and their machine said that it's putting out 15 volts. OK, then. Time to start tracing wires.
I found the problem last weekend. It was indeed one of the amps. When I built the stereo, I used an old amp that had been in 2 previous cars, and it was a cheap swap meet special even back in the day. Well, this amp wasn't shutting itself off like it was supposed to do when it gets the signal from the head unit. Still, 15 years of service out of a cheap amp isn't bad at all.
How I located the problem: I have a dedicated battery lead going to both amps via a fuse box. I pulled this lead off the battery and there was continuity to ground. I then pulled each fuse in the box until the meter showed no continuity. That fuse has been temporarily removed.
Now I've got no sound coming out of the kick panel speakers, but the woofers and dash speakers still work. Time to add a stereo refresh to my project list (when I'm not out driving the car, now that I found the problem).
I found the problem last weekend. It was indeed one of the amps. When I built the stereo, I used an old amp that had been in 2 previous cars, and it was a cheap swap meet special even back in the day. Well, this amp wasn't shutting itself off like it was supposed to do when it gets the signal from the head unit. Still, 15 years of service out of a cheap amp isn't bad at all.
How I located the problem: I have a dedicated battery lead going to both amps via a fuse box. I pulled this lead off the battery and there was continuity to ground. I then pulled each fuse in the box until the meter showed no continuity. That fuse has been temporarily removed.
Now I've got no sound coming out of the kick panel speakers, but the woofers and dash speakers still work. Time to add a stereo refresh to my project list (when I'm not out driving the car, now that I found the problem).
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