Battery draining

[Minderbinder3]

Been chasing a battery drain for a while now. I believe it has always been there since I got the Jeep this past March. After 2 days the battery does not have enough voltage to start the Jeep.

Over the past week or so I been watching it closely and it drains about .10 volts every hour.

I have slowly taken the “accessories” off the battery connection, including winch, light bar, and radio and monitored the drain hoping that I could eliminate something easy. Only the main cables are still connected to battery and it still drains at same rate.

Battery is about a year old and tests good when I charge it.

Any ideas?

 

[WestCoastDan]

Not sure this will really help, since you say the only thing connected are the main cables, but...

How I always start the process of chasing a parasitic drain is to turn off every switch in the vehicle, close all doors, etc. and get your DVM.
Then go to your fuse box and remove a single fuse.
W/ the DVM, check for voltage across the contacts for that circuit (measure in the fuse box, not across the actual fuse).
If you see voltage across the contacts in the box, then that circuit is drawing current. If you don't measure voltage, then there is no current draw on that circuit.
Replace the fuse and move to another. In a perfect world, you will not measure any voltage between the contacts.
Do this across each fuse and it will tell you where to start looking for the root cause.

 

[Minderbinder3]

Not sure this will really help, since you say the only thing connected are the main cables, but...

How I always start the process of chasing a parasitic drain is to turn off every switch in the vehicle, close all doors, etc. and get your DVM.
Then go to your fuse box and remove a single fuse.
W/ the DVM, check for voltage across the contacts for that circuit (measure in the fuse box, not across the actual fuse).
If you see voltage across the contacts in the box, then that circuit is drawing current. If you don't measure voltage, then there is no current draw on that circuit.
Replace the fuse and move to another. In a perfect world, you will not measure any voltage between the contacts.
Do this across each fuse and it will tell you where to start looking for the root cause.

Sounds like a plan but will have to happen in a couple of days.

Thanks

 

[Minderbinder3]

Read through a couple of similar threads and went to check the under hood light to make sure it is not the culprit. Mine doesn’t have one but then I noticed this wire mounted to the under side of the hood like a ground.

Anybody know what it is for?

 

[TJ Jim]

Grounds the hood. Reduces electrical interference in the radio. Static electricity builds up as air passes over the hood.

 

[Rickyd]

Like dan said.check each circuit until you find the big draw. I would start by measuring the amp draw at the battery though. Then isolate circuits until that draw is back under the allowable limit(there is always a normal draw for the pcm,etc). Fix offending circuit

 

[Minderbinder3]

What exactly do you mean by the amp draw at the battery?

 

[Rickyd]

What exactly do you mean by the amp draw at the battery?

i have amp clamp multimeters to put around the cable. Set to dc amps it measures the amperage draw of the whole system.the factory has a spec for maximum draw.

They are very handy for things like checking your alternators actual output, what a starter draws,or anything you want to check without disconnecting or can't disconnect.

You could play with voltage but it is shooting in the dark when compared to being able to measure the quantities of electricity in each circuit. Looks like harbor freight and others have cheap versions

 

[B1Toad]

If you have a meter that can measure DC amps and milliamps follow this procedure. Milliamps would be best but start with amps just in case the load exceeds 1 amp, then switch to milliamps on the meter (unless the load shows up over 1 amp which is a lot) A clamp on meter will work too but may not be as accurate, and we are talking pretty small amounts of current so accuracy is important.

https://innova-electronics.helpscou...use-a-multimeter-to-test-for-a-parasitic-draw

 

[03coloradowrangler]

Unless I have missed it, have you completely disconnected the battery isolating itself from everything on the vehicle and checked its status? like pull it from the jeep and set it on the work bench / floor and check its charge level periodically.

Thought something was parasitically discharging my trucks battery.. after months of f'ing with everything I found out the battery was simply just self discharging on its own.

 

[Jerry Bransford]

I'd charge the battery overnight with a bench top charger then take it to a battery shop and have them do a 'load test.' Properly conducted a load test is only way know the battery's true health and condition.

Make sure they hold the load on the battery the full 15 seconds required for an accurate load test result. If the electrical load is removed from from the battery too soon the test can give an erroneous 'good' indication for a battery that is actually bad or marginal.

 

[B1Toad]

I'd charge the battery overnight with a bench top charger then take it to a battery shop and have them do a 'load test.' Properly conducted a load test is only way know the battery's true health and condition.

Make sure they hold the load on the battery the full 15 seconds required for an accurate load test result. If the electrical load is removed from from the battery too soon the test can give an erroneous 'good' indication for a battery that is actually bad or marginal.

The issue I have with that is as lot of places use the little 130 amp hand held load tester which I don't believe is enough for a starting battery which needs to be load tested at 1/2 it's CCA. The Harbor Freight 500 amp carbon pile load tester works good but you won't find any parts stores using anything close to it. I bought one years ago when they were $35 and it's my go to. Just a couple weeks ago my neighbor was having issues with a 800 CCA FLA and the 130 amp OTC said her battery was good but the HF 500 failed it miserably long before the 15 seconds was up.

 

[Jerry Bransford]

@B1Toad that's why I included 'properly conducted' in front of load test. Any improperly conducted test will produce invalid results.

 

[TNHEADDUCK]

An old school way of doing a draw test is to unhook your negative battery cable and put a test light between the ground cable and the ground post on the battery, the test light should be lit up some. It helps if you can position the light so you can see it or have a helper, start pulling fuses until you see a noticeable difference in the brightness of the test light. This will identify the circuit of the fuse and its componets to make it easer to trace down. I used this method in the 70s and early 80s before I could afford a analog volt meter ,digital meters didn't come around until the late 80s best i can remember.

 

[Vtx531]

Get a DC clamp meter and check if there is amp draw. I wouldn't waste time taking battery to be tested - usually they don't even know how to work the machine properly (plus they are designed as a sales tool to sell batteries, not a real diagnostic).

You could have a bad battery that was caused by amp draw, then if you get a new battery you will kill that one too.

 

[Jerry Bransford]

Get a DC clamp meter and check if there is amp draw.

Those are usually too insensitive to find and accurately report low amperage draws, those are usually only accurate with higher amperage flows. If it's much below 2 amps most clamp meters will not be a good choice. For low draws that are still enough to eventually drain the battery I'd use a VOM meter with the ability to accurately read lower amperage draws needs to be inserted in series with the battery and its connector.

 

[Dr. Internet]

I researched and decided to buy a certain battery. I went to the store and told the guy what I wanted and he got it and we installed it. He then decided to test it with some kind of Flash Gordon equipment on a little stand. He rolled it out, connected it to the battery posts, hit a couple of switches and told me that it said my battery was no good. Well, said I, I'm glad I just bought this brand new battery from you, so you can replace it. Wait a minute, he says, that can't be right. He hits a couple of more switches and then announces that my alternator is bad (note - Jeep not running). I started laughing so hard I almost hurt myself. I just closed the hood and went home. Battery (and alternator) have worked fine for the last six years.

Vtx531!!!!

 

[Minderbinder3]

Finally got a chance to get around to working on this issue. Disconnected battery cables and fully charged battery. I let it sit for a couple of days afterwards and it held the charge well and only lost about .2 volts in 3 days.

Then I did the above mentioned test by pulling each fuse and testing for constant current. I found that the horn fuse and IOD fuse both have constant power. The horn fuse has full battery voltage going through it (12.79) and the IOD fuse has 10.98 going through it. Pulled both out and Jeep starts and runs but quickly realized that IOD fuse controls the dash gauges and interior dome light.

This Jeep was wrecked in its early life and the airbags deployed and not replaced. It has an after market horn button on dash with wiring bypass because if you connect the horn up like it should be it blows constantly. I believe the clock spring is bad.

I don’t need the horn fuse installed but can I do about the battery drain from the IOD?

 

[Rickyd]

Finally got a chance to get around to working on this issue. Disconnected battery cables and fully charged battery. I let it sit for a couple of days afterwards and it held the charge well and only lost about .2 volts in 3 days.

Then I did the above mentioned test by pulling each fuse and testing for constant current. I found that the horn fuse and IOD fuse both have constant power. The horn fuse has full battery voltage going through it (12.79) and the IOD fuse has 10.98 going through it. Pulled both out and Jeep starts and runs but quickly realized that IOD fuse controls the dash gauges and interior dome light.

This Jeep was wrecked in its early life and the airbags deployed and not replaced. It has an after market horn button on dash with wiring bypass because if you connect the horn up like it should be it blows constantly. I believe the clock spring is bad.

I don’t need the horn fuse installed but can I do about the battery drain from the IOD?

View attachment 486623

Did you do as dan suggested when checking voltage? Do you know if those circuits are normally supposed to draw power? How much do they draw? Its a modern vehicle.it is supposed to constantly draw power on certain circuits

 

[Vtx531]

Finally got a chance to get around to working on this issue. Disconnected battery cables and fully charged battery. I let it sit for a couple of days afterwards and it held the charge well and only lost about .2 volts in 3 days.

Then I did the above mentioned test by pulling each fuse and testing for constant current. I found that the horn fuse and IOD fuse both have constant power. The horn fuse has full battery voltage going through it (12.79) and the IOD fuse has 10.98 going through it. Pulled both out and Jeep starts and runs but quickly realized that IOD fuse controls the dash gauges and interior dome light.

This Jeep was wrecked in its early life and the airbags deployed and not replaced. It has an after market horn button on dash with wiring bypass because if you connect the horn up like it should be it blows constantly. I believe the clock spring is bad.

I don’t need the horn fuse installed but can I do about the battery drain from the IOD?

View attachment 486623

Voltage doesn't mean there is a draw. 10xx. volts is curious though. Something not right there but I don't see where you measured any amperage. Obviously there are certain ciruits that are supposed t9 be constant hot (show voltage) when the key is off.