Any Ideas on what is causing this over night battery drain? I can drive around all day doing shopping chores and such and truck will start all day long, but, park it at night, and will not start in the morning.

Have done the test with the light to the battery ground and positive post with the ground cable disconnected and there is no indication of a draw.

What else should I check, where else should I look...

A curiosity occurred a while back when it was doing the same thing I am describing now...I was disconnecting the negative cable when parking the truck to save the battery, then when I was away the battery was stolen out of the truck, I won't go into the Homer Moment, that caused that to happen. Subsequently I had to purchase a new battery, and the overnite drain abated, now I know that some might say...well sure it was a new battery...but, it never drained away for over a year until I parked the truck this past winter.

I charged the battery with a trickle charger for about 36 hours until the charger indicated that it was full, then put it back into the truck, and my over night drain returned.

I am baffled to say the least, I should also mention that vehicle electricity has always been a challenge for me, so short of taking it to an auto electric shop for diagnosis, any information you provide for me here is most certainly appreciated, but, needs to be very specific.

Thank you all in advance for any information that will save me any time and money, and rid me of this extremely annoying problem.

Later...

A PS: to the above, this also started when I had the transmission rebuilt, and installed a new clutch, a removal and reinstall I did myself.

 

this happened to me the other day...i accidentally left the high beams pushed forward...even though my lights were off...it drained my battery....just a thought..?

 

'didnt happen till this past winter'


You're battery died during winter and is now in effect, dead, won't hold a charge, hell I bet if you take a multimeter and watch the battery you can see the volts drop by the minute. Go have the bat tested but I bet its dead.

 

You need a multimeter that is capable of measuring amps to test for excessive key-off draw. Anything over 50mA is too much. You hook the leads of the multimeter in series with the battery positive terminal and the positive battery cable to perform this test.

To find where the draw is (after you have verified that you have a key-off draw), you must divide and conquer the electrical system of the truck. With the multimeter hooked up and showing the draw, start pulling fuses. When the draw goes away, you have found the culprit circuit. Divide and conquer again. Test each part of the circuit, see what is drawing power.

 

That post should be a sticky. I've seen this question way to many times.

 

This thread helped me solve my electrical issue with my ford ranger. Here's the scenario. I woke up one Friday morning with a bone dead battery. First issue I've ever had with it. I drove a different vehicle to work and that afternoon charged the battery. The next morning it was dead again. Went to Advance and bought a new battery and installed it. From Saturday to Monday morning the truck was not touched. I went to crank it Monday morning to drive to work and it was bone dead again. Bottom line, I had a significant drain and I narrowed it down to the relay that engaged my AC clutch. How I discovered this was I put my battery charger on the battery and I heard an audible "click". I disconnected the charger and touched the post again and "click". It was the AC clutch. I thought I had left the key on but no, everything was off. I replaced that ten dollar relay and all is well.

 

I'm running into something I think as well. If I don't drive my truck for a week the battery is dead. Which seems strange because I've not driven other vehicles for a couple weeks and they always start up.

I have a multimeter but when you say hook it up in series to the battery, I'm not entirely sure what that means. I've always checked current with the multimeter from ground/negative black lead on the multimeter and the red/postive to the multimeter lead.

Thanks,
-Nigel

 

When you run into the problem of a car battery that seems to work fine when re-starting just after a few hours but being dead or close to dead after sitting for say 8-10 hours, i.e. overnight, then the FIRST THING you do is to unhook battery from the vehicle, and THEN test its voltage, WRITE IT DOWN

Now wait an hour and re-test battery voltage, if its LOWER then battery is self draining, internal short in a cell, this is the most common battery failure, usually happens after 4 years and up, but can happen to BRAND NEW battery, manufacturing defect
So do this test FIRST, always

To test for a vehicle issue, a system/light in a vehicle that is draining the battery when key is off
Simple test is same as above
After driving vehicle, unhook 1 battery cable, doesn't matter which one, then let it sit overnight, or a few days, hook cable back up
If you can start engine then battery is OK, vehicle is draining battery
If you can't start engine battery is bad, self draining

To test vehicle drain you disconnect 1 battery cable, either one
KEY OFF
Set your Volt Meter to AMPS
Connect 1 Volt meter lead to open battery terminal
Connect other lead to removed battery cable
This is what he was referring to by "series" wiring, (battery cable----------volt/amp meter-------------battery)

Meter will show you how many AMPS are being used by the vehicle with key off
The YEAR of the Ranger matters, some have keyless entry(fobs), these have to be "listening"(on) all the time , same for Alarm systems, they must be ON when key is OFF, or whats the point of having an alarm, lol

0.07amps or 70milliamps is the most you should see
If you see more then you need to pull out 1 fuse at a time, in engine bay fuse box first, to see what fuse causes AMP draw to drop