Car is 94 Civic Si. No CEL.

So this has happened a couple times already. My car won't crank due to low battery voltage. The starter is fine I tested that by jumping the starter when my voltage was good.

Right now my Batt volts is at 11.90VDC. I charged it up yesterday and it was up around 12.90 which was about 16 hours ago and the car started fine with that.

I looked for parastic drain as per the FAQ and all its drawing is 15ma.

Could it be a faulty battery?

If you guys need anymore info just ask.

 

That draw seems a tad high exp with a eg si that has next to nothing that requires draw or keep alive for the normal 30 mins as with new cars.


Also how lo g after shut off did you check draw? Try again after 30 mins cause i very rarely see a honda that has any draw after 30 mins most are 5-15mins tops

 

According to the FAQ the limits is between 3-15 milliamps(ma) and they said as long as its under 50 milliamps it should be good.

the draw is still the same 15 milliamps. I forgot to mention I have an two-way alarm. I think that would affect some power draw.

 

Sometimes you can have enough volts but no cold cranking amps?? You can take it to almost any auto parts store and have it charged and tested. It might be an easy way to narrow your problem down.

 

Do a load test on the battery, attach your meter to the battey and check the voltage as you crank your motor.
charge the battery first then check the battery under a load.
if the voltage drops more than 2 volts there is a bad cell in the battery and needs to be replaced

 

this.

i'd imagine the battery will drop to like 5 volts. a tester will probably read some stupid-low amperage under load.

props for the op testing things like a pro! and yeah 15ma is near-nothing.

 

Yes i under stand all that, but 50 ma is a general rule to go by with any auto. I have an ase in electrical so i am aware of it. And yes big props to you for doing a proper diag. 2way very well could be cause of higher ma draw. As others have stated check load draw, and cranking amps

 

The 12.90 volts after charging could be due to a surface charge. Turn on the headlights and measure after 5min.

What the voltage measure with the engine running?

 

50ma is accepted because at that rate a small 400cca or so battery will remain charged for around 5 weeks. Larger batteries even longer.His draw is some what high for that MY vehicle,but well within the acceptable limits.And his alarm is the likely culprit. I think he has a bad battery.

 

Too late to take it to the autoparts store now...it's after 9pm eastern time

The voltage went down to 8.90VDC when I turned the crank key.

Yeah it dropped to like 8.90VDC and thanks!

How do I check cranking amps? still a noob at this

It is at 13.46 Volts

I only had this battery for around 5 months.

 

To check cranking amps you need to take somewere and have tested in car, most multimeters will not support that kind of amps.

 

So I bought a new battery and the same thing happens to the car. I noticed when I crank the car the speedometer jumps while cranking and reaches as high as 100mph.

Is the blk/red wire after the relay supposed to read voltage at a static state?



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There should only be voltage on that wire in the start position. Once you let go of the key there should be no voltage. If there is, Id be looking at the ignition switch.

 

I tested it by setting my multimeter to the DCV, diconnected the connector from the starter cut relay, tested the blk/red with black testerand touched a positive supply with red tester. if that helps at all.

 

So I was doing the Parastic drain test wrong...forgot to switch the lead tester on the multimeter to 10A.

Now for the results!
When I first tested it I got 107-109ma. I troubleshooted it to the ceiling light. The ceiling light was in the door position and all doors were closed.

Now when I turned the ceiling light to the off position. I got a parastic drain of 22-27ma. I pulled all my fuses and nothing changed that reading. Is this acceptable? I got a 2 way paging alarm.

Wouldn't the ceiling light in the door position with the doors closed shouldn't be pulling any milliamps? Mine is pulling 85ma with it.

FYI...When I installed a LCD light for the dome light would still be lighted up when in the door position and doors closed, but not as bright when its in the on position. So I just switched it back to the stock incandecent light bulb.

If I leave the dome light in the off position it would not trigger my alarm but if i leave it on the door position my alarm would be triggered if I opened the door/doors.

 

All right I sum'd everything up from the beginning to fixing the problem

First off my car had a no start issue which led me to troubleshoot a couple things.

First off was to check my battery's voltage: 11:89...not good in my book. So I charged it. BAM! voltage within limits after a couple hours. I think it was fixed. After 2 days of it being charged It didn't want to start again! :x Now I buy a new battery just to make sure it wasn't the battery. So I did some research.

Next test that I did was a parastic draw test. Results were 111ma of draw. Troubleshooted down to my dome light. With dome light in door position and door closed it was pulling that amount of miliamps. In the off position, it was only pulling 24-27miliamps. Mind you I have a 2-way paging alarm. So I charged up my battery again and left the dome light in the off position. Next thing you know it didn't want to start the next day. :x FML!

So now I'm thinking I got a short or something. So I disconnect my alarm and the parastic draw test shows 7ma of draw. Charged up battery again cuz it was low and now she starts again Next day she started but it was kind of weak if you ask me. So now I'm thinking its my charging system.

I did a couple of test with my charging system.
idling at 900rpm no accessories on: 12.28 volts
idling at 900rpm with accessories on: 11.86 volts
@ 2000rpm no accesories on: 12.64 volts

Now I think my alternator is bad :x I put the results of this text on a couple of forums and they tell me my alternator is dying and they said I should change it. As I was doing more research I came across an alternator thread where a guy was having the same voltage issue as me. He changed his alternator and still got the same results. :?

I don't feel like spending $100+ and not fixing the problem. Some they had a couple more tests like checking for continuity between the alternator and + battery connector. Also to look at grounds.

My test between alternator connector and battery connector yielded .02 ohms of resistance...which seemed pretty good to me. Next was to look at my engine bay grounds. I FOUND THEM ALL CORRODED!!!! Seems like the problem. So I cleaned the - battery terminal to body which was corroded. Same with the transmission to the chassis and the one with the thermostat gound was not in great shape.

Finally when I did all of that I decided to do a parastic draw test. Results: 3ma of draw compared to a week earlier which was 7ma of draw.

Now I started my car with the battery volts @ 12.31 which is below average. It started like when I first hot her! Pretty Fast! So I did the check for the charging system

idling with no accessories on 14.28 volts
idling with headlight, AC, radio, and defroster on 14.10 volts.

Damn that was a stressful problem!