Weird power drain...can't figure it out

[rxm6]

I've had this power drain lately and I thought I figured it out but it turns out I just extended the time it takes to drain my battery. Originally, power drain was .44 amps and so I disabled the aftermarket radio and it dropped to .11. But that is still too much I think. My other car takes .04 amps sitting around, so I don't think the 240 is much different. I've already pulled all the fuses and I checked the trunk light but everything checks. However, is the clock on the dash supposed to stay on all the time? any other car I've had, the clock face turns off.

[94_240sx]

However, is the clock on the dash supposed to stay on all the time? any other car I've had, the clock face turns off.

Yes, it's on in 240.

[numbnuts240]

i'm pretty sure that clock is on all the time, but it definitely doesn't draw enough power to kill your battery within a short amount of time.

[94_240sx]

I have 3 cars. Nissan, Mazda and Mitsubishi. Somehow my s13 draws the most. It's not just me I have 2 close friends who own s13s and their batteries die quite often.

[rxm6]

alright....but in a week? seems a little odd to me. I mean, this is not my DD so I have no problem leaving the battery disconnected, but it seems to me like I should be able to leave a car sitting a month at least. Right?

Does anyone know what Nissan factory spec is on amp draw for an S13???

[bahamet]

Did you check your alternator? Every time you fire up your car, it should recharge it enough, or your battery isn't holding any power.

[Arrow]

I had / have an intermittent power drain on my car it wasn't until recently when I figured it out (at least most of it) I thought it was my radio at first - my battery would die if the car sat for more than 3 days w/o running - I disconnected the radio fuse and it still died on me at around the 4 day mark.

Come to find out that my trunk light would randomly stay lit. And it would come on randomly throughout my driving. Basically I believe that the sensor that turns it on has gone out and thus would allow the light to come on randomly and if it happened to be on whenever I parked the car then my battery would suffer the consequences... However since I removed the trunk light I have yet to leave my car sitting for an extended period of time to test if that solved all of my problems and I haven't taken the time to run out to my car with my multimeter to check the drain on the battery... might do that sometime soon though...

I know that you mentioned that you checked the trunk light, but it might be worth taking another look at it... or disconnecting the light all together like I did.

[rxm6]

Sounds like a good idea...I mean its pretty useless anyway as trunk lights go. Did you disable it from the switch or just remove the bulb?

[moulton712]

by taking out the bulb, you make the switch irrelevant.

so just take out the bulb

[94_240sx]

Yeah, I checked that one too and it was okay. I could see light turning off if I lower the lid everytime. I did replace both switches below door striker. Those switches turn on the interior lights when doors are open. I also pulled each fuse and didn't start the car several days and see which one does that, but couldn't find any. Bad thing is my battery has drained several times, so I don't think it's holding the charge well.

One of the members, cparker spent like $500 to fix this problem on her s13 vert. She went to ealership to fix it, and it was a short inside of the door panel somewhere near window motor/switch.

[rxm6]

Really....I was hoping it wasn't a short, but I'm starting to believe....ug. Well I have an SE so no window motors, so I assume no wiring in the doors??? I've already removed all the fuses, but I didn't let the car sit with all the fuses gone. Though, there must be a quicker method than letting the car sit around and possibly draining the battery.

[rxm6]

Went home tonight and decided to work on it a little bit. This is what I found. Sitting in my driveway, the car is taking 5.25mA. In my experience, this seems somewhat higher than what I'm used to, but I'll take it. I followed Arrow's advice and disconnected the trunk light switch and let my meter sit with the car for about an hour. In that time, the 5.25mA did not alter one bit. So then I'm left with a few questions. One is, is 5.25mA normal?? Is that what other people are getting?

The other question I'm left with is what is this??? I never gave mind to it until I traced it today...this is definitely not oem.

Here is a picture of where the wire originates:



And here is a picture of where the wire is grounded:



As you can see the wire has been hap-hazardly tied on to another wire and soldered for a ground. Thats just disgusting work. Is this the ground for that sensor? If so, where did it go originally?

[OutToWinPAHC]

If you had a short you would know it. But it looks like you know how to use a current meter. So what you can do is remove the fuses and one by one put the leads across the fuse terminal and see what circuit is pulling. PR if you clamping make a half moon wire, put it in place of the fuse and clamp that wire. Find the circuit the most current then trouble shoot it from there.

And 5mA aka .005A is nothing.

This is work, discharging a batteries at 10,000Amps, so it just sounds small. But yeah try using the meter and poking around, if you had a short you would be clearing fuses so I dont think that. And remeber current flow NEGATIVE TO POSITIVE in DC circuits

[rxm6]

well see I know 5mA is nothing...i mean thats what most cars draw...4-5mA for the clock and ecu. One thing I did notice though thats weird is that every time i connect the battery, the amps will sit at 5.25mA maybe 2 seconds and then slowly increase to 11mA and then shoot back to 5.25mA. What is this taking power? Normal?

[OutToWinPAHC]

Charging caps?

[Dimitri]

My battery drains every so often. With the OEM radio disconnected, dome light removed, door closed and trunk light removed it draws .05 amps aka 50 mA.

Can someone test their "non-battery-draining" 240sx to verify what a "normal" drain is ?

Dimitri

[Amarant]

Well, I'm glad I'm not the only one with this issue... although i wish i were only drawing 5mA...

I have a '90 HB that's gone through 2 or 3 batteries already. I just bought another new one but I'm leaving it disconnected.

When I initially hook up my ammeter, I see a 450mA (yes, almost half an amp) draw. I know thats more than just charging caps... It stays there for a few seconds then drops to around 40mA.

I've disconnected my aftermarket head unit and isolated the draw in the lines to my two amplifiers. The amp powering my subwoofer isnt pulling any current. The amp powering my speakers is pulling about 10mA. So that still leaves a 30mA draw from the rest of the car.

After reading the thread, I checked the trunk light but it was already pulled....

I've been racking my brain for a while and thought I'd look for some answers elsewhere.... Any new ideas?

[Vegascorbin]

And remeber current flow NEGATIVE TO POSITIVE in DC circuits

Now don't go confusing people with facts I won't even bring the Hole movement vs Electron movement into this

For the non-technical reading this current DOES NOT flow positive to negitive as you would think. It does, as stated, flow negitive to positive. In cars this is not normaly a concern UNTIL you get to a diode or other semiconductor.

I assume the Photos are of a phone switch? That bank of batteries will power that 5mA draw for ..oh about a year or 5!

[560]

Hello everyone,
Am new to this website and am glad that am here ,
I just bought recently a 240sx and the car seems like had a 5 speed swap before and I have problem, the car keeps drain the battery and the battery brand new just bought it 5 days ago cause I thought the battery is the problem but I was checking all the fuses today with multimeter and I found so far 2 short circuit,
1- the shift lock stay on when the ignition and the car off
2- car interior light stays on ,on the multimeter even if the switch off and the car turned off and read 12.13 DC so I think that's enough to drain the battery!!!!