Hey everyone!
I have a 2007 Jeep Liberty with a newish (1 year old) battery and original alternator.
Whenever I don't run my vehicle for 2 to 3 days, it won't start as the battery is dead. For context, the electronics are very basic in this vehicle - power windows, after market single din stereo, Anker sound sync module to add Bluetooth and that is it. No subs, no heated seats, no additional lights etc.
I am able to boost my vehicle and get it going and once I charge the battery, it works fine until I don't run it for a few days again.
This has been going on for probably 5 years and I have replaced the battery 3 separate times thinking that was the issue but I am no longer convinced.
Also for as long as I can remember (I bought the vehicle in 2011 with 36,000 km on it), the headlights would dim every time I rolled up my windows, if that matters.
I did the multi-meter testing from ChrisFix's video on my alternator and it all seemed to check out fine according to these tests.
What should I do next to figure out the issue? Does it sound like a parasitic drain or a bad alternator?
If it has a parasitic draw it would usually drain overnight. Try starting it the next morning see if died out overnight then I would proceed with a parasitic draw test. In the meantime I would check your battery terminals for tightness or corroded terminals I will even go as far as peeling some of the insulation off to see if you have corrosion. Then check your ground cables at body for tightness or corrosion. It could be that loose or corroded wires are causing insufficient current flow for the alternator to charge your battery.
Also, its an automatic and has approx. 200k km on it.
Try searching Scotty's Youtube channel whenever you have a problem. He's got a video for almost everything.
How to Fix Battery Drain in Your Car (Parasitic Draw Test)
https://www.youtube.com/watch?v=B__DqK90IIc
There are several YouTube videos covering Parasitic Draw, but check out this one:
https://www.youtube.com/watch?v=lRcj1fQcWwU
I'll try what you recommended Th3kr1s, thank you!
So I did what recommended and did not find any issues.
I then proceeded onto the parasitic draw test from Scotty that mountainmanjoe recommended and I found the following:
- The drain right now is hovering between 200 and 250mV
- When I pulled the fuse for my cigar lighter, it reduced this drain from 100 to 150 mV
- When I pulled the fuse for my ignition switch (square fuse under the hood), it reduced the drain about 30mV
- It looks like the regular drain for my vehicle if I don't have the cigar lighter fuse in, is about 80mV (which seems high considering the vehicle does not run any fancy electronics).
Would that 100 to 150mV difference from the cigar lighter cause my battery to drain within a 2 day period so much that I cannot start my Jeep?
Would the best course be to change out the cigar lighter?
Thanks!
@flag
You mean milliamps (mA), not millivolts (mV) right?
250mA is a bit high, but still shouldn't drain the battery in a few days. So something else is coming on when you're not there. Gremlins.
Is there anything plugged into cigar socket like phone charger? That fuse also powers the OBD port (make sure it's clean and not corroded), and possibly other accessories you might have (USB ports?)
@mountainmanjoe
I believe its millivolts as Scotty indicated in his video (I am using a resistor hooked onto clamps, hooked onto the battery). The setting on my multimeter is for volts and I used the "m" setting in that section, so I assume its mV.
There is a phone charger that is plugged into that socket which powers my Anker SoundSync bluetooth module (there is always power to the cigar lighter). If I unplug it while I am testing, the mV draw only decreases slightly (5 - 10 mV).
I'll check the OBD port as well, no other accessories hooked up to it as far as I am aware.
Doing some searches on the Jeep forums it looks like other people have similar issues with trailer lights being wired into this fuse so I will need to check that as well.
@flag
I see. That was the voltage across the resistor. So now you use ohms law (V=IR) to calculate the current. How many ohms is your resistor?
I would try disconnecting the bluetooth thing and see if your battery still gets drained.
@mountainmanjoe
It is a 1 ohm 10 watt resistor.
I'll definitely give it a go but I had this issue before having the bluetooth module and considering the minimal change in mV when I unplug it, I don't think that is it.
I cannot recall exactly when I started having this issue but a few years back, there was a recall on these Jeep's and they added a hitch to help support the back end. I believe either the dealer or a friend of mine installed the lights for a trailer as we were fishing lots then & if the trailer lights are hooked into the lighter fuse at all, this may be my issue based on some quick Google magic.
I am going to try a few things over the next few weeks to see if I can narrow it down further.
@flag
Gotcha . With a 1ohm resistor 1V = 1A , so in fact it is a 250mA drain.
You might be on to something with the added wiring. Pull the cig fuse and see if battery still goes flat.
@mountainmanjoe
Will do, I just need to find some days where I will have my vehicle parked.
Also spoke with my friend and he re-calls hooking up the trailer lights so I will pull the fuse to see if I have battery drain and if not, then will begin to investigate the wiring.
Thanks for the help!