LT1 charging system problem...
Thread Starter
Instructor
Joined: Jul 2003
Posts: 118
Likes: 0
From: Woodbine MD
LT1 charging system problem...
Hello Folks,
Have a '92 LT1 in which the battery keeps dying. Battery is about 4 months
old. Takes it about 2-3 days of sitting idle to die.
The LCD on the cluster (after a jump start takes place) as well as all the
dash lights are flickering somewhat. The Voltage on the LCD display is
jumping from about 13.4 volts to around 14.5 (even saw a couple of 15s in there) after watching the display for about a minute.
HELP!!!! and THANKS!
Can't do much of this for now ---> :steering:
Have a '92 LT1 in which the battery keeps dying. Battery is about 4 months
old. Takes it about 2-3 days of sitting idle to die.
The LCD on the cluster (after a jump start takes place) as well as all the
dash lights are flickering somewhat. The Voltage on the LCD display is
jumping from about 13.4 volts to around 14.5 (even saw a couple of 15s in there) after watching the display for about a minute.
HELP!!!! and THANKS!
Can't do much of this for now ---> :steering:
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: LT1 charging system problem... (trvette)
Dash flicker and voltage jumping I don't think are related to your excessive leakage current problem. First check at night for a vanity mirror light left on or an underhood light on, or the console compartment light stuck on. Do you have an aftermarket radio, audio amplifier, radar detector or car alarm? Check em. Some CFers have found their seat adjust switch was stuck on. Next disconnect the neg batt cable and put an ammeter (VOM test meter) between the batt terminal and the neg cable to measure leakage current (wait until the courtesy lights time out and switch the VOM to lower and lower full scale current until you can read the leakage current). My 87 draws 27 ma. and GM says it should be below 50 ma. If yours is too high, remove the 15 A courtesy light fuse and then start pulling fuses one at a time until you observe a dramatic drop in the ammeter. That circuit then will have to be examined further. If no fuse finds the leakage, remove the nut on the jump start bolt behind the battery and remove one at time the 8 red wires on that bolt and watch the ammeter. Furthermore, there are some circuit breakers that will have to be dealt with and a few circuits that are not fused. Let us know what you found.
Thread Starter
Instructor
Joined: Jul 2003
Posts: 118
Likes: 0
From: Woodbine MD
Re: LT1 charging system problem... (jfb)
Could this maybe (oh hopefully) be a bad battery? Not sure where the
voltage is measured on the cluster....at the battery...alternator or where?
The battery holds a charge but not for long (last jump I let it run for
about 15 minutes only to come back about a hour later and finding the
car completely dead . Would one see flickering dash lights and voltage jumping all over the place (again between about 13.3 to 14.6) while the car is running if the battery was in bad shape?
:confused:
[Modified by trvette, 4:25 PM 10/19/2003]
[Modified by trvette, 4:26 PM 10/19/2003]
[Modified by trvette, 4:27 PM 10/19/2003]
voltage is measured on the cluster....at the battery...alternator or where?
The battery holds a charge but not for long (last jump I let it run for
about 15 minutes only to come back about a hour later and finding the
car completely dead . Would one see flickering dash lights and voltage jumping all over the place (again between about 13.3 to 14.6) while the car is running if the battery was in bad shape?
:confused:
[Modified by trvette, 4:25 PM 10/19/2003]
[Modified by trvette, 4:26 PM 10/19/2003]
[Modified by trvette, 4:27 PM 10/19/2003]
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: LT1 charging system problem... (trvette)
If you jumped the battery and let the engine run thinking you would charge up the battery in 1/2 hour of running or so, you are in for a lesson! A car battery needs to be charged for a long period, like 24 or more hours to fully charge it up. If you have a charger, disconnect the negative cable and charge the battery for at least 24 hours. Let the battery sit for 2-3 hours and them measure its voltage (still disconnected). A fully charged battery measures 12.9 or higher volts, 12.0 or lower is considered discharged. If your battery is fully charged, let it sit for 24 hours (disconnected) and measure the voltage again, it should show fully charged. If you have a battery at the end of its life, it will self discharge significantly overnight disconnected and you should replace it. A defective battery could cause the dash voltmeter to jump around but in my experience this is rare.
Even so, you should also measure the amount of leakage current after the courtesy lights time out and determine if you have excessive leakage current.
Even so, you should also measure the amount of leakage current after the courtesy lights time out and determine if you have excessive leakage current.
