We flat tow our 2014 Jeep Wrangler and have for years. The last two times we towed, we couldn't start the Jeep without a jump. After the first time I took it to the Jeep dealer and had the battery, alternator, etc. checked and everything was fine. After the first jump, we had no problems at all until we just towed again today and now we have the same issue. The only thing that I an say is different is that one tail light is out when we tow, it is on in normal operation, just out when towing. We have changed nothing else, except to add a battery disconnect after the last time (5 days ago) We towed from FL to NC with multiple stops, no issues, then it happened and now it did it again.We use a M & G braking system, have had it for years and it works off the airbrakes, so no power going there. So we only have the wiring harness beyond that.Any ideas? I don't even know where to start on this one!

What position are you leaving the ignition key in? Any chance you've left it in the ACC or RUN position? You don't need the key at all for the Wrangler as it does not have a steering wheel lock.

The normal position we always have. We do have a steering wheel lock on ours. That's the odd thing, we haven't done anything differently. We have had the same rig and same systems since 2014. I am wondering if there is some sort of short that is draining the battery. I just don't know!

According to Roadmaster Roadmaster You should be disconnecting the battery.Did someone install a relay to do this and it has failed or the control circuit has failed?

Is it a tail light or turn signal - brake light that is out? I would clean the plug where you plug into the Jeep, sounds like your turn signal and charge wire have poor connections.

We installed the battery disconnect after the first dead battery and then today, it's dead again.It is all lights that are out on the passenger side of the Jeep, the RV lights are fine and they work fine when we aren't hooked up.Would having a poor connection in the plug cause the battery to drain? I'll give it a shot, but I can see that it might be the cause of the light not working, but not sure about draining the battery.......that's my quandary!

Jeep battery dead after towing | Good Sam Community

Sam_Spade
Explorer
Jun 06, 2017
Potcakes wrote:

So, a short somewhere could cause the battery to drain in 5 or 6 hours, even if we have the battery disconnected (the negative side)? Is that correct?

No. Absolutely, positively NO.
Potcakes
Explorer
Jun 06, 2017
I will check for a fuse, I"m not sure about that.

We have the battery disconnect to on the negative, but since it only happens when we are towing and it happened before and after the disconnect being put on, I suspect it must be in the wiring harness. I think I have the old harness from a previous MH and Jeep, so I may try to see if that will work and cause the same problem. If it does, then I think the problem must be in the motorhome part.......of course this plan only works if the old harness fits!

So, a short somewhere could cause the battery to drain in 5 or 6 hours, even if we have the battery disconnected (the negative side)? Is that correct?
Tom_Barb
Explorer
Jun 06, 2017
What wiring harness do you have?

some how the battery is finding a ground, or the opposite, to complete the circuit.

We remove the ( - ) and isolate it with an old plastic cap.
enblethen
Nomad
Jun 06, 2017
Does the MH have separate fuses for the trailer connector?
Yes, a loose wire in a connector could be causing fault. Normally this should blow a fuse as light outages indicate.
Potcakes
Explorer
Jun 06, 2017
We installed the battery disconnect after the first dead battery and then today, it's dead again.

It is all lights that are out on the passenger side of the Jeep, the RV lights are fine and they work fine when we aren't hooked up.

Would having a poor connection in the plug cause the battery to drain? I'll give it a shot, but I can see that it might be the cause of the light not working, but not sure about draining the battery.......that's my quandary!
corvettekent
Explorer
Jun 06, 2017
Is it a tail light or turn signal - brake light that is out? I would clean the plug where you plug into the Jeep, sounds like your turn signal and charge wire have poor connections.
enblethen
Nomad
Jun 06, 2017
According to Roadmaster Roadmaster You should be disconnecting the battery.
Did someone install a relay to do this and it has failed or the control circuit has failed?
Potcakes
Explorer
Jun 06, 2017
The normal position we always have. We do have a steering wheel lock on ours. That's the odd thing, we haven't done anything differently. We have had the same rig and same systems since 2014. I am wondering if there is some sort of short that is draining the battery. I just don't know!
sch911
Explorer
Jun 05, 2017
What position are you leaving the ignition key in? Any chance you've left it in the ACC or RUN position? You don't need the key at all for the Wrangler as it does not have a steering wheel lock.

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Jeep battery dead after towing

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