Electrical

Sphinx · 07-07-2006, 05:03 PM

hey i don't know what is wrong with my 1989 supra for some reason it drains my battery overnight and can't find out what it is can any one point me in the right direction please.

dcrusupra · 07-07-2006, 11:43 PM

Bad ground somewhere. How do you know its draining the battery?

Sphinx · 07-08-2006, 02:51 AM

i know because i can't started it in the morning and thats why

mrnickleye · 07-08-2006, 03:56 AM

Bad grounds don't drain batteries. Things that are grouded do. Like interior lights left on. Brake lights staying on. Radios, amps, etc on when key is off.

Since its draining over night, AND if the battery is a real good one (because a weak battery won't hold a charge over night anyway), then you have a pretty big draw.

With the car OFF, remove the Neg battery terminal and place a mechanics test light between the terminal and the battery post. A VOM will work too. If the light shines BRIGHT, then you have a big draw. A 1 volt draw is OK.

If it does not shine, or is very dull, then there is no draw, or just a very small one. It is common to have a very small draw.

If there is a big draw, you can pull one fuse at a time to see what circuit is the problem. Hopefully you find it and can then trace the circuit down and fix it. Other wise you'll end up having a shop do it.

Have the battery and charging system checked. An alternator that is weak won't keep the battery fully charged.

Sometimes working on these troubles can cause you to go bald !!

07-07-2006, 05:03 PM	#1
Sphinx Stock Join Date: Jul 2006 Location: COMPTON Posts: 2	Electrical hey i don't know what is wrong with my 1989 supra for some reason it drains my battery overnight and can't find out what it is can any one point me in the right direction please.

07-07-2006, 11:43 PM	#2
dcrusupra 500whp yet? Join Date: Aug 2005 Location: Plantation, Fl. Posts: 1,052	Bad ground somewhere. How do you know its draining the battery? __________________ New Rebuild My CarDomain

07-08-2006, 02:51 AM	#3
Sphinx Stock Join Date: Jul 2006 Location: COMPTON Posts: 2	reply to: How do you know its draining the battery? i know because i can't started it in the morning and thats why

07-08-2006, 03:56 AM	#4
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	Try this Bad grounds don't drain batteries. Things that are grouded do. Like interior lights left on. Brake lights staying on. Radios, amps, etc on when key is off. Since its draining over night, AND if the battery is a real good one (because a weak battery won't hold a charge over night anyway), then you have a pretty big draw. With the car OFF, remove the Neg battery terminal and place a mechanics test light between the terminal and the battery post. A VOM will work too. If the light shines BRIGHT, then you have a big draw. A 1 volt draw is OK. If it does not shine, or is very dull, then there is no draw, or just a very small one. It is common to have a very small draw. If there is a big draw, you can pull one fuse at a time to see what circuit is the problem. Hopefully you find it and can then trace the circuit down and fix it. Other wise you'll end up having a shop do it. Have the battery and charging system checked. An alternator that is weak won't keep the battery fully charged. Sometimes working on these troubles can cause you to go bald !! __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Loss of power and electrical fire	mister	MKIII Supra	0	12-16-2008 10:17 PM
Electrical Troubleshooting	go.stfu	MKIII Supra	0	10-21-2007 09:32 PM
i need some electrical help fast please!!	zuni	MKIII Supra	7	07-15-2007 05:18 PM
Oil Pressure...Mechanical or Electrical???	Luvs2slide	MKIII Supra	5	08-23-2006 12:42 AM
Intermittent Electrical Problems on a ’93 MKIV	gjs_cds	Shops & Part Reviews	0	05-22-2006 02:39 PM