# Mystery parasitic drain **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** electrical-wiring, jeep\ **Created:** [June 6, 2020, 10:58pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423 "2020-06-06T22:58:01Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![brantjs30](https://avatars.discourse-cdn.com/v4/letter/b/bb73d2/32.png) [@brantjs30](https://community.cartalk.com/u/brantjs30)\ **Post date:** [June 6, 2020, 10:58pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/1 "2020-06-06T22:58:01Z")
I’m at a loss. I’m trying to help a friend with a 2009 Jeep Patriot, 2.4L. The battery is draining overnight. The owner threw a new battery at it and is still having the problem, and brought it to me to help out. Here’s what I have done: Doing parasitic drain testing by disconnecting negative from battery and hooking multimeter between cable and terminal, I measure 1.8A. I’ve individually pulled all fuses in the fuse box under the hood (as far as I can tell, this is the only fuse box). No changes in current draw doing this. I disconnected alternator and starter (power cables and signal wires). No change in current draw. The battery reads 12.6V when charged and the car is off, and the alternator has the correct output when running. When she brought it to me, I did leave it overnight without doing anything and it did drain significantly below 12.6V. I can’t remember exactly what the reading was. What else can I check to try to locate the problem? I really thought it would be either a fused circuit or the starter/alternator. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [June 6, 2020, 11:01pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/2 "2020-06-06T23:01:12Z")
When you disconnected the negative cable and connected the meter, did you wait at least an hour for any computers/modules to go to sleep? Tester ---
**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\ **Post date:** [June 6, 2020, 11:55pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/3 "2020-06-06T23:55:23Z")
So if I read this correctly there is still a drain even if all the fuses are disconnected? Look at the Pos battery cable and see if there is a thin spot rubbing and shorting out to ground. ---
**Author:** ![Cougar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cougar/32/21348_2.png) [@Cougar](https://community.cartalk.com/u/Cougar)\ **Post date:** [June 7, 2020, 1:08am UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/4 "2020-06-07T01:08:33Z")
The fuses inside the panel under the hood are usually power at all times. The fuse panel in the dash (there is one) is usually powered on with the ignition switch. There should be a smaller wire tied to the battery that supplies power to the panel under the hood. Disconnect that wire from the battery and see if the current drain goes away. If there still is a current draw then you need to check the other wiring from the positive post. The starter does not need to be looked at unless there is a wire tied to the hot side of the solenoid feeding power to something. The main fuse panel might be tied to the battery there possibly. Sometimes the alternator can cause a draw when a diode inside it goes bad but it seems that isn’t happening in this case. ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [June 7, 2020, 1:08am UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/5 "2020-06-07T01:08:51Z")
There’s a fuse or fuse box you haven’t yet found. Any aftermarket alarm or remote starter? > [@Tester](#): > > did you wait at least an hour for any computers/modules to go to sleep? Sorry, but I can’t imagine any system so poorly designed to draw over an amp for an hour before going to sleep, each time the car is turned off. The EVAP system goes into action several hours after shutoff. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [June 7, 2020, 1:13am UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/6 "2020-06-07T01:13:21Z")
[https://gm-techlink.com/?p=6831](https://gm-techlink.com/?p=6831) Tester ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [June 7, 2020, 1:26am UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/7 "2020-06-07T01:26:24Z")
Nowhere does that say a steady \>1 amp for an hour or more. ---
**Author:** ![brantjs30](https://avatars.discourse-cdn.com/v4/letter/b/bb73d2/32.png) [@brantjs30](https://community.cartalk.com/u/brantjs30)\ **Post date:** [June 7, 2020, 8:21pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/8 "2020-06-07T20:21:57Z")
The car hasn’t been run in several days at this point. I believe I had it disconnected over an hour. I had it disconnected all last night and just hooked up the leads on the multimeter and it’s still got the same output. I left the leads connected and will check again later this afternoon. Doors haven’t been opened and remote hasn’t been activated since yesterday. ---
**Author:** ![brantjs30](https://avatars.discourse-cdn.com/v4/letter/b/bb73d2/32.png) [@brantjs30](https://community.cartalk.com/u/brantjs30)\ **Post date:** [June 7, 2020, 8:24pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/9 "2020-06-07T20:24:24Z")
> [@Barkydog](#): > > So if I read this correctly there is still a drain even if all the fuses are disconnected? Look at the Pos battery cable and see if there is a thin spot rubbing and shorting out to ground. I just pulled the wire loom material off the section that sleeved the positive and ground cables. There was some rubbing on the positive but no sheathing damage on the ground. I don’t think it was grounding, but I wrapped some electrical tape on the rubbed spot anyway. No change in current draw. ---
**Author:** ![brantjs30](https://avatars.discourse-cdn.com/v4/letter/b/bb73d2/32.png) [@brantjs30](https://community.cartalk.com/u/brantjs30)\ **Post date:** [June 7, 2020, 8:30pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/10 "2020-06-07T20:30:18Z")
> [@circuitsmith](#): > > There’s a fuse or fuse box you haven’t yet found. > Any aftermarket alarm or remote starter I don’t think so. Everything appears to be stock. The only positives (2 wires) coming off the battery go to the fuse panel under the hood and to the starter, and the only negative goes to a grounding point on the block. I haven’t seen any non-factory wiring or aftermarket equipment anywhere. ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [June 7, 2020, 8:55pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/11 "2020-06-07T20:55:40Z")
> [@circuitsmith](#): > > There’s a fuse or fuse box you haven’t yet found. According to the “Owners Manual” There is only the one under the hood. > **[770.pdf](https://msmownerassets.z13.web.core.windows.net/assets/publications/en-us/Jeep/2009/Patriot/770.pdf)** > > 12.48 MB ---
**Author:** ![tcmichnorth](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tcmichnorth/32/25126_2.png) [@tcmichnorth](https://community.cartalk.com/u/tcmichnorth)\ **Post date:** [June 7, 2020, 10:57pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/12 "2020-06-07T22:57:58Z")
With your voltmeter put red lead to positive post and Black lead anywhere else on top of battery but not on the negative battery post. If you get any reading, the top of your battery needs cleaned. A dirty battery will draw some current between posts. Take some baking soda and water and clean the top of the battery. Do not let baking soda get inside battery. ---
**Author:** ![brantjs30](https://avatars.discourse-cdn.com/v4/letter/b/bb73d2/32.png) [@brantjs30](https://community.cartalk.com/u/brantjs30)\ **Post date:** [June 8, 2020, 2:34pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/13 "2020-06-08T14:34:40Z")
> [@tcmichnorth](#): > > With your voltmeter put red lead to positive post and Black lead anywhere else on top of battery but not on the negative battery post. If you get any reading, the top of your battery needs cleaned. A dirty battery will draw some current between posts. Take some baking soda and water and clean the top of the battery. Do not let baking soda get inside battery. Hadn’t ever heard this before. In this case, it’s not the problem. I checked to be sure, but it’s a new battery and very clean. No corrosion on terminals or terminal clamps. ---
**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\ **Post date:** [June 8, 2020, 2:59pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/14 "2020-06-08T14:59:49Z")
I cannot help you with this problem but I will say that after a preliminary look regarding an electrical problem I always try to round up a factory wiring schematic and look it over to get a feel for what I’m dealing with. I hate going into things blind and in most cases a problem has been resolved without even having hands on the car. A proper manual or schematic might be a good investment at this point. Have you tried removing relays on the off chance that a set of points could be sticking? Sometimes high current relays will burn the contacts, cause them to develop very rough surfaces, and stick together. ---
**Author:** ![brantjs30](https://avatars.discourse-cdn.com/v4/letter/b/bb73d2/32.png) [@brantjs30](https://community.cartalk.com/u/brantjs30)\ **Post date:** [June 8, 2020, 11:52pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/15 "2020-06-08T23:52:27Z")
Looked at one more thing today just for the sake of checking. Last night I left the ground disconnected and positive connected. Checked the battery yesterday and then again today with no loss of voltage sitting on its own. ---
**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\ **Post date:** [June 8, 2020, 11:54pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/16 "2020-06-08T23:54:41Z")
If there is no ground there is no circuit to draw voltage, no surprise ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [June 8, 2020, 11:55pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/17 "2020-06-08T23:55:04Z")
What did you expect? The battery isn’t connected to the vehicle with either of the cables disconnected. ??? Tester ---
**Author:** ![brantjs30](https://avatars.discourse-cdn.com/v4/letter/b/bb73d2/32.png) [@brantjs30](https://community.cartalk.com/u/brantjs30)\ **Post date:** [June 9, 2020, 2:26am UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/18 "2020-06-09T02:26:43Z")
> [@Tester](#): > > What did you expect? > > The battery isn’t connected to the vehicle with either of the cables disconnected. > > ??? > > Tester Agreed. Really was also just checking to ensure battery wasn’t self-discharging, but honestly didn’t expect to have any sort of ‘aha’ moment. Kinda grasping at straws here. Should have seen current draw stop by either disconnecting the lead to the alternator and starter, or by pulling fuses. Doesn’t make sense to be bleeding current any other way. ---
**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\ **Post date:** [June 9, 2020, 2:58am UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/19 "2020-06-09T02:58:35Z")
Did you ever try pulling relays? ---
**Author:** ![brantjs30](https://avatars.discourse-cdn.com/v4/letter/b/bb73d2/32.png) [@brantjs30](https://community.cartalk.com/u/brantjs30)\ **Post date:** [June 9, 2020, 10:36pm UTC](https://community.cartalk.com/t/mystery-parasitic-drain/165423/20 "2020-06-09T22:36:16Z")
> [@ok4450](#): > > Did you ever try pulling relays? I pulled the relays in the block behind the drivers side headlight. No change in current draw. Not sure if this is the only location for relays, but couldn’t find any references to other locations. [Next page](https://community.cartalk.com/t/mystery-parasitic-drain/165423.md?page=2)