ELEC B Fuse, Battery Drain Issue

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Mikey178
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Hi,

I have a 2000 Infiniti QX4. Been dealing with this issue of battery drain recently. Started when I parked vehicle in the cold for 5 day. Went to start it after and the battery was dead, got it boosted and drove home fine. Used it for 3 days more and began to notice the interior lights dimmer than usual. Starting seem to struggle until it wouldn't start anymore, just clicking. Starter was replaced about a year ago and battery was 3 years old and never had the battery fail me. I replaced the battery thinking it was the issue and it was back to normal. 4 days later, issue re-occurs again, does not start, battery seemed to be drained. I could boost it to start.

Hooked up voltmeter to battery and it was reading 8.33V with no load and everything off, not good, couldn't start the vehicle, boosted the vehicle and it was charging but at idle would only be at 11.2V - 11.6V, rev the engine and it would go up to 12.8V max, so I figure the alternator is charging and working but the battery was pooched. Turn the vehicle off and the reading drops from 11.6V and continuously goes down by 0.01 every second or two until it gets to about 8.8V. Got it exchanged and that is where I'm at today.

I have done some research and found that I may be dealing with a battery drain issue. With the new battery installed I checked the readings. 12.4V with no load, hooked up the battery, started the vehicle and its charging and everything is back to normal. Turn the vehicle off, reading on the battery is slowly decreases by 0.01V evey minute but almost stablizes around 12.35V - 12.4V. Hooked up to do a fuse pull test, negative cable attached to the - terminal on the battery, with the positive cable disconnected from the + terminal. I put a 10A ampmeter between the new battery + terminal and the positive cable. Reading with no fuses pulled is 0.4A (This I think is too high), pulled fuses from the engine fuse box with no change. Pulled the following fuses from the fuse box behind the coin box with it causing the amp to drop to 0.04A: Hazard (20), ELEC B (27) & Audio Amp (4).

At this point, I have left these 3 fuses pulled and checking the reading on the battery, reading is stable at 12.37V, checked for the past 2 hours every 30 minutes. I think I have isolated where the drain is coming from at least to these 3 fuses. Hazard and Audio Amp (ACC) had the least impact on the drop of the amps that I was reading and the significant drop was from ELEC B.

I've gone through the electrical service manual to try and locate what fuse ELEC B was feeding but have not found anything on it. Can anyone help with this. Im going to continue checking the voltage reading on the battery today to ensure there is no futher drop (drain).

Sorry for the long post but just wanted to ensure who ever could help could see where the issue began and what I have done up to now.

Thanks in advance.


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Towncivilian
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ELEC B is fuse No. 24. No. 24 plays a part in many illumination and lighting functions. Open EL section and search for "No. 24" and you'll find all it controls. As to something that specifically might be causing the power drain, I'm afraid I can't think of anything specific.

Something more trivial: do you still have the stock Bose system installed? If not, you can remove the rear Bose amp completely to remove that power drain.

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Mikey178
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Wow, thanks Towncivilian, the simple details I missed :confused:, I had thought ELEC B was fuse no 27 as it was the last in the first column of fuses so assumed it was the last one in the EL section which shows as no 27, now that you point out it is actually no 24, I will look at it a bit more in the EL section.

As you mentioned it does control quite a bit of illumination and lighting functions which I see. Hopefully I can follow each of them to try and isolate where the drain is pulling from. Anyone with any further ideas will be appreciated.

I had actually pulled the rear amp out when I did the sound system install.

Thanks.

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Towncivilian
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Good luck figuring out your power draw.

Looks like you can't pull the "AUDIO AMP" fuse since it seems to supply power to the head unit as well.

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Mikey178
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Thanks for the suggestions Towncivilian. I tried following fuse 24 and after 30 minutes of tracing and testing. I called a friend who is a Honda tech. He came by and checked the the battery voltage when stopped, during crank and then while running and he said it may be a bad diode in the alternator as he noticed it fluctuate. Sure enough, I drove the vehicle with the 3 fuses pulled and 2 days after installing the new battery as I was driving the dash lights began to dim as I sat at a stop light and then brighten up when driving. I was also noticing a whining sound that went along with the RPM.

Decided to change out the alternator as I had bought it but didn't install as I wanted to rule out other possibilities. Swapped out the alternator, took about 2 hours and checked everything again. After 1 day I put the fuses back in and did further volatage tests, everything has checked out for the last 2 days and the battery is holding its charge, no drain, no whining sound, lights are bright consistantly.

So everything seems to be back to normal at this point.

Thanks for the help and suggestions.

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Towncivilian
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Sounds good, I'm glad you figured it out. Usually the "BRAKE", "A/T OIL TEMP" (if equipped), and the battery light will light up when the alternator is going south, strange that yours didn't.

sammy6
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Car: 2002 nissan pathfinder

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Well I have a 2002 Pathfinder...same issue with battery drain.Pull AMP Audio fuse everything good except I have no radio .Not sure if issue is with amplifier ...wiring from amp to radio or the radio itself.
Do not have electrical schematic.
Any suggestion greatly appreciated....
(PS..replaced alternator because of bad bearing so do not believe alternator is the cure as in previous post)....scratching my head for sure! :crazy:

yeldogt
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What type of alternator? The cheap alternators can be bad out of the box .. sadly they are junk. You should have looked into getting yours rebuilt. The cheap ones come with lifetime warranty -- so they soon great .. but they bank on people using them in old cars and never keeping them ... the labor is more vs the alternator.

Check the output of the alternator -- if your not getting close to 14 volts -- it's not working correctly.


Do you still have the old one? -- normally Hitachi.

sammy6
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Thanks for the reply..,..well I did buy cheaper one for around $120...but I did check output while running and I was getting around 14.5v..so the alternator is testing good..(I even removed battery cable once while running vehicle under load..light radio ect all good)..When I turn vehicle off battery reads 12.5.v approx. I replaced battery with a two month old one ..same problem..dead battery next morning.I replaced rear amplifier and relays for amp with ones I pulled from junkyard.Dead battery once again.
I'm not sure what else is on Amp Audio fuse ckt. I know radio has to be because once I pull the amp fuse the radio has no power. Next day with AMP fuse pulled..battery reads 12.1v. I wondering if radio is pulling everything down seeing it still has power going to it at all times.
Again .....any suggestions would be greatly appreciated!..thank you..

sammy6
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Car: 2002 nissan pathfinder

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Sorry I missed that last question....I have to look..I know it was a Hitachi though (I recently replaced two others in vehicles believe it or not for bearing problems)


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