Parasitic battery drain

InOmaha

InOmaha

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Last week the Jeep wouldn't start twice. I put the charger on for 5-10 mins and it would start up.

I did a battery parasitic load check and got zero amps. I cleaned of some filthy corroded terminals covered in grease and tightened them down. The battery is 5 months old. The Jeep started fine all week.

But today, I opened the door for something and my radio turned on when I closed the door and stayed on. The dome lights went off so I opened the door and the radio stopped. I turned off the radio.

Door switch? Failing radio. Bad circuit? Ghost? Has anyone else had this happen?
 
It did it again this morning. Has anyone ever had a random battery drain issue?
 
Have you tested the alternator? Does it have an aftermarket stereo or alarm?
 
I haven't tested the alternator yet.

It's got the original radio. I put it on the charger for 5 mins and it started right up.
 
There's a procedure for testing the alternator in the FSM, I would check it out.

Also, I believe the voltage regulator is built into the PCM. To me these symptoms sound like a bad battery or bad battery terminals however.
 
It's a new battery and I cleaned the terminals and reseated them. They were caked with old dielectric grease, dirt, and corrosion.

Could it have something to do with the rear gate? It seems to happen days after I load something in the back.

I'll have the alternator tested and then maybe change the battery cables and check ground.
 
I'd change the terminals regardless. They need to be changed every so often anyways.

I'm not sure what it would have to do with the tailgate though. I can't recall, is there a light switch on the tailgate?
 
Just the 3rd brake light. It's just odd that it seems to happen the after open it.

Terminals are easy, so I'll get tha alternator checked and change those.

Here are the connections after scrubbing. You can see what the looked like before in the areas I didn't reach with the wire wheel.

I'll buy new connectors and clean the wire connections up when I put them on.

2019-10-06 10.47.34.jpg
 
Mine was the radio.
Pull the IOD fuse. Set the multimeter to amps. plug the meter into the 2 terminals.
Draw should be next to nothing. If draw is above .010 (from memory) you have narrowed the problem. Mine register .3 amps, 300 milli-amps.

If the draw isn't on the IOD then disconnect the big wire that runs from the battery to the fuse box.
connect an amp meter between the cable and terminal. Start pulling fuses until the draw goes low.

If the draw isn't in the fuse box you can test the alternator for a bad diode in the same way. Separate the battery fat wire from the alternator, connect the ampmeter between the cable and terminal.
 
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xackley said:
Mine was the radio.
Pull the IOD fuse. Set the multimeter to amps. plug the meter into the 2 terminals.
Draw should be next to nothing. If draw is above .010 (from memory) you have narrowed the problem. Mine register .3 amps, 300 milli-amps.

If the draw isn't on the IOD then disconnect the big wire that runs from the battery to the fuse box.
connect an amp meter between the cable and terminal. Start pulling fuses until the draw goes low.

If the draw isn't in the fuse box you can test the alternator for a bad diode in the same way. Separate the battery fat wire from the alternator, connect the ampmeter between the cable and terminal.
Click to expand...
You can also use a test light in place of the ammeter, it will light up with a parasitic load.
 
I'm going to stop thinking outloud on the thread. My guess is the alternator or bad wire/connections. It went to charging zero. I bet the battery isn't getting charged enough and gets gets weaker as the week goes on. It dies every 5 to 7 days. I'll get the alternator checked tomorrow.
 
I charged the battery overnight and left for work a little bit later this morning so I could leave the headlights off. I made sure everything electronic was off; lights, radio, cabin fan, etc.

The Jeep ran much better then it did at the end of last week, so I'm definitely leaning towards alternator. I'll get it checked over lunch today and if it's failing I'll look at a 136 amp rather than 117 amp. That way I'll have extra power for anything I may add in the future.
 
InOmaha said:
I charged the battery overnight and left for work a little bit later this morning so I could leave the headlights off. I made sure everything electronic was off; lights, radio, cabin fan, etc.

The Jeep ran much better then it did at the end of last week, so I'm definitely leaning towards alternator. I'll get it checked over lunch today and if it's failing I'll look at a 136 amp rather than 117 amp. That way I'll have extra power for anything I may add in the future.
Click to expand...
A bad alternator cannot make the radio stay on. That is a fairly large issue that shouldn't be ignored. If it was my Jeep I'd be fairly certain a new alternator would not fix the problem. I'd be looking at the radio or ignition switch.

Edit: and I wouldn't consider remembering to turn off the radio a fix, it's a good idea but not a fix
 
I'll get the alternator checked. If it's fine, I'll pull the radio fuse and sing to myself on my 6 mile commute. If my issue goes away after pulling the radio fuse, I'll track that circuit down looking for issues.

I'll work my way down the list. Today's alternator check will be the second step after I checked for a parasitic draw.
 
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It's a failing voltage regulator on the alternator. Which probably explains why it feels so random. Sometimes it's charging somewhat and sometimes not charging. I'll buy a new one and put it in tonight.

Or maybe order something like this off Amazon since the remanufactured alternators at the generic parts stores don't get the best reviews. I'll check the dealer pricing too, but I bet that's really high.

https://www.amazon.com/dp/B007Y853DA/?tag=wranglerorg-20
 
Last edited:
This is from the 2006 Factory Service Manual. Page 8F-31

VOLTAGE REGULATOR
DESCRIPTION The Electronic Voltage Regulator (EVR) is not a separate component. It is actually a voltage regulating circuit located within the Powertrain Control Module (PCM). The EVR is not serviced separately. If replacement is necessary, the PCM must be replaced.


https://wranglertjforum.com/threads...ice-manuals-fsm-technical-documentation.4618/
 
Interesting. Maybe the kid testing it just assumed it was that when the machine spit back it was the alternator. They tested the battery, starter, and alternator. So how would a regular person test it? I don't want to toss money at parts.

The dealer I called said $280 for a remanufactured alternator and the parts guy said they've been discontinued so I couldn't get one from them anyway.
 
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