Eng Cont fuse draining battery? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

harleys · 03-09-2008, 02:57 PM

First i'll start with some info on the car:
89 Nissan 240sx Coupe
Sr20det swap
and other goodies that don't really relate to this problem.

Problem:
For a while now, the battery is dead if the car sits for more than a couple of hours. So today I finally broke out the multimeter to see what was drawing all the power. I figure out that it is the FL25A Eng Cont fuse under the hood. It's drawing about 10a with nothing at all on inside the car. I believe this fuse is for the ecu, so i tried disconnecting the ecu and it still has a draw.

Can anyone tell me what else this fuse powers? What could be drawing the power? I'm so tired of having to keep a jump box with me to start my stupid car. I tried giving all info that is related to the problem, if you need to know something else, just tell me.

Thanks in advance for the help.

slider2828 · 03-09-2008, 07:48 PM

I think pretty much the ecu.... check your grounds on the ecu... Pull it and see if it is still drawing.

harleys · 03-09-2008, 09:35 PM

i did pull the ecu. even unplugged it still has the draw.

slider2828 · 03-09-2008, 11:31 PM

Check the wiring diagram.... sorry, try also the mafs.... which is connected o the Ecu as well.

harleys · 03-11-2008, 11:38 PM

update: ok. figured out that it is the 02 sensor drawing power. if i unplug it, i have no draw at all. the red wire and white wire in the plug going to the sensor have continuity. not sure if it is supposed to, but doesn't sound right.

DataXUnknown · 03-11-2008, 11:48 PM

I have the same problem! I'm gunna check my fuse tommorow, also the O2 sensor. Thanks! (My car is an '89 S13 with a blacktop SR)

PIwakawa · 03-12-2008, 02:46 AM

my car had the same problem, just ran w/o O2, since there is no emission in florida.

Mangudai · 03-12-2008, 07:44 AM

^ Doesn't thats affect gas mileage? Im assuming you mean the front o2 sensor..

harleys · 03-12-2008, 11:59 AM

Quote:

Originally Posted by DataXUnknown

I have the same problem! I'm gunna check my fuse tommorow, also the O2 sensor. Thanks! (My car is an '89 S13 with a blacktop SR)

There are hundreds of things that could be draining your battery. It took me couple hours to narrow it down to this.

Drift_86 · 05-02-2016, 07:08 PM

I'm having same exact problem could some one pitch in and help me out?

03-09-2008, 02:57 PM	#1
harleys Zilvia Member Join Date: Apr 2006 Location: Cape Coral, Florida Age: 40 Posts: 159 Trader Rating: (0) Feedback Score: 0 reviews	Eng Cont fuse draining battery? First i'll start with some info on the car: 89 Nissan 240sx Coupe Sr20det swap and other goodies that don't really relate to this problem. Problem: For a while now, the battery is dead if the car sits for more than a couple of hours. So today I finally broke out the multimeter to see what was drawing all the power. I figure out that it is the FL25A Eng Cont fuse under the hood. It's drawing about 10a with nothing at all on inside the car. I believe this fuse is for the ecu, so i tried disconnecting the ecu and it still has a draw. Can anyone tell me what else this fuse powers? What could be drawing the power? I'm so tired of having to keep a jump box with me to start my stupid car. I tried giving all info that is related to the problem, if you need to know something else, just tell me. Thanks in advance for the help. __________________ -harley

03-09-2008, 07:48 PM	#2
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 6,040 Trader Rating: (13) Feedback Score: 13 reviews	I think pretty much the ecu.... check your grounds on the ecu... Pull it and see if it is still drawing. __________________ Turn and Burn!

03-09-2008, 09:35 PM	#3
harleys Zilvia Member Join Date: Apr 2006 Location: Cape Coral, Florida Age: 40 Posts: 159 Trader Rating: (0) Feedback Score: 0 reviews	i did pull the ecu. even unplugged it still has the draw. __________________ -harley

03-09-2008, 11:31 PM	#4
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 6,040 Trader Rating: (13) Feedback Score: 13 reviews	Check the wiring diagram.... sorry, try also the mafs.... which is connected o the Ecu as well. __________________ Turn and Burn!

03-11-2008, 11:38 PM	#5
harleys Zilvia Member Join Date: Apr 2006 Location: Cape Coral, Florida Age: 40 Posts: 159 Trader Rating: (0) Feedback Score: 0 reviews	update: ok. figured out that it is the 02 sensor drawing power. if i unplug it, i have no draw at all. the red wire and white wire in the plug going to the sensor have continuity. not sure if it is supposed to, but doesn't sound right. __________________ -harley

03-11-2008, 11:48 PM	#6
DataXUnknown Post Whore! Join Date: Sep 2006 Location: Mission Viejo, CA Age: 35 Posts: 2,934 Trader Rating: (30) Rides Gallery: DataXUnknown Feedback Score: 30 reviews	I have the same problem! I'm gunna check my fuse tommorow, also the O2 sensor. Thanks! (My car is an '89 S13 with a blacktop SR)

03-12-2008, 02:46 AM	#7
PIwakawa Join Date: Nov 2005 Location: Orlando Age: 45 Posts: 5 Trader Rating: (0) Feedback Score: 0 reviews	my car had the same problem, just ran w/o O2, since there is no emission in florida.

03-12-2008, 07:44 AM	#8
Mangudai Zilvia Addict Join Date: Jan 2007 Location: South Posts: 656 Trader Rating: (0) Feedback Score: 0 reviews	^ Doesn't thats affect gas mileage? Im assuming you mean the front o2 sensor..

05-02-2016, 07:08 PM	#10
Drift_86 Post Whore! Join Date: Jan 2010 Location: Los Angeles, South Gate Age: 38 Posts: 3,682 Trader Rating: (60) Feedback Score: 60 reviews	I'm having same exact problem could some one pitch in and help me out? __________________ Want to roll fenders, custom gauge pod pm me

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