Battery drain, pulsing testlight
06-26-20, 08:19 AM
#1
Rookie
Thread Starter
Battery drain, pulsing testlight
1998 ES300. Just bought it and prev owner says over a couple weeks battery will drain if not started.
I noticed the seat memory SET button was stuck down.
Before unsticking it I put a test light between NEG battery cable and NEG battery post. The light is pretty bright and has a rhythmic pulse as if it was mimicking a turn signal. Bright, dim, bright, dim....
I unstuck the button and same thing.
any ideas?
I noticed the seat memory SET button was stuck down.
Before unsticking it I put a test light between NEG battery cable and NEG battery post. The light is pretty bright and has a rhythmic pulse as if it was mimicking a turn signal. Bright, dim, bright, dim....
I unstuck the button and same thing.
any ideas?
Last edited by davet1; 06-26-20 at 10:58 AM.
06-26-20, 12:40 PM
#2
Lexus Fanatic
What is the battery voltage? FYI the pulsing is an issue with these cars the alternator is not strong enough and the flickering is magnified because of how the injectors pulse. To greatly reduce the problem put in a Highlander 100amp or 130amp alternator.
Your problem also could be more obvious because your battery is not in the best of shape. Does the dome light flicker?
Your problem also could be more obvious because your battery is not in the best of shape. Does the dome light flicker?
06-26-20, 02:42 PM
#3
Rookie
Thread Starter
Thanks.
Right now I'm not sure what the voltage is of the battery. I get the pulsing test light with the engine turned OFF. How would an alternator cause pulsing with engine off and injectors not operating?
The dome light does not pulse.
Right now I'm not sure what the voltage is of the battery. I get the pulsing test light with the engine turned OFF. How would an alternator cause pulsing with engine off and injectors not operating?
The dome light does not pulse.
06-26-20, 08:11 PM
#4
Lexus Fanatic
Pulsing test light is probably a bad test light.
06-27-20, 02:32 PM
#5
Pole Position
Hello,
If the battery goes flat after a while, it means that you have a parasitic draw. To diagnose it, be sure to have as little turned on as possible, then disconnect the negative battery terminal, and connect an amperemeter between the negative side of the battery and your negative terminal. Let it sit for a second, since your amperage may jump up a little, but then it should drop close to zero. If not, start pulling all the fuses one-by-one until the value would drop. That would mean that the faulty system is now deactivated, and you will have to diagnose the system to which this fuse belongs.
What you can also do is make your own test light out of a regular bulb and a couple of wires (to exclude a possibility of a bad test light), and then start unplugging all the fuses while you have your light connected, until the "pulsing" will stop.
Hope this helps and best of luck!
If the battery goes flat after a while, it means that you have a parasitic draw. To diagnose it, be sure to have as little turned on as possible, then disconnect the negative battery terminal, and connect an amperemeter between the negative side of the battery and your negative terminal. Let it sit for a second, since your amperage may jump up a little, but then it should drop close to zero. If not, start pulling all the fuses one-by-one until the value would drop. That would mean that the faulty system is now deactivated, and you will have to diagnose the system to which this fuse belongs.
What you can also do is make your own test light out of a regular bulb and a couple of wires (to exclude a possibility of a bad test light), and then start unplugging all the fuses while you have your light connected, until the "pulsing" will stop.
Hope this helps and best of luck!
Last edited by Arsenii; 06-27-20 at 02:37 PM.
06-29-20, 07:37 AM
#7
Lexus Fanatic
Try the bulb on a different 12volt source.
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