Battery Problems

[Munilover]

Hey

So I have 2 brand new Optima Batteries and my alternator is fine. I have checked all of my fuses and I cant find a draw.
Ding dong dead after 24hrs of being parked. Starts fine after a jump, and all is good as long as I'm driving everyday. 81 CJ7 why you do me so wrong? Anyone with a suggestion.
Cheers

Oh and do I really have to buy an optima battery charger?

 

[jakeh937]

Hey



So I have 2 brand new Optima Batteries and my alternator is fine. I have checked all of my fuses and I cant find a draw.

Ding dong dead after 24hrs of being parked. Starts fine after a jump, and all is good as long as I'm driving everyday. 81 CJ7 why you do me so wrong? Anyone with a suggestion.

Cheers



Oh and do I really have to buy an optima battery charger?

The only way to find a draw is either with a amp meter or using a volt meter inline. You said you checked your fuses, how did you do so? And why do you say your alternator is fine?


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[JeffP]

Step 1... connect an amp meter between your positive battery post and cable. With everything “off” I suspect you will still see a substantial current draw.
Step 2... remove fuses, one at a time, until you see a drop on the meter. Make a note of which circuit / fuse it is.
Step 3... continue as with step 2 until the current draw is zero.
step 4... return to the circuit(s) where there is a current draw, then one by one eleminate each load on each circuit until you find the one causing trouble.
Remember some items like a clock, computer memory etc. have a very minor current draw but nothing that should drain a battery in a short period.
While you say your alternator is good... maybe the regulator is the problem... or the field remains energized with the engine off. It will still charge, but radidly drain your battery when not in use.

 

[Munilover]

The only way to find a draw is either with a amp meter or using a volt meter inline. You said you checked your fuses, how did you do so? And why do you say your alternator is fine?


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Hey.
I had the alternator tested at a shop when I replaced the batteries, they said it was good.
I left thinking all was fine. And was until I had it parked for a day and a half.
So I used a multi meter inline and got a 35milliamp draw. I then went and pulled all of my fuses individually and non of them where the problem.

 

[Munilover]

Step 1... connect an amp meter between your positive battery post and cable. With everything “off” I suspect you will still see a substantial current draw.
Step 2... remove fuses, one at a time, until you see a drop on the meter. Make a note of which circuit / fuse it is.
Step 3... continue as with step 2 until the current draw is zero.
step 4... return to the circuit(s) where there is a current draw, then one by one eleminate each load on each circuit until you find the one causing trouble.
Remember some items like a clock, computer memory etc. have a very minor current draw but nothing that should drain a battery in a short period.
While you say your alternator is good... maybe the regulator is the problem... or the field remains energized with the engine off. It will still charge, but radidly drain your battery when not in use.

Hey
Thanks. I did steps 1 through 4. But I will try it again tomorrow. I was rushed and might have missed something.

I have been reading about the regulator today so I will look into that if my second attempt at steps 1-4 don't work the second time.
Thanks for your help.

 

[jakeh937]

Hey.

I had the alternator tested at a shop when I replaced the batteries, they said it was good.

I left thinking all was fine. And was until I had it parked for a day and a half.

So I used a multi meter inline and got a 35milliamp draw. I then went and pulled all of my fuses individually and non of them where the problem.

That's exactly what I was going to say. Sort of a long shot but I was working on a machine at work which had a draw and would be dead after a day. Alternator was charging like normalZ So like you, i used the volt meter on the battery and found I had a small draw. Pulled all fuses and still had it. Used a amp clamp and started around wires and harness and traced it down to the alt. Replaced alt and draw was gone. Something internal went bad and was pulling just enough juice to kill the battery after a day. Unplug the wires to your alt and let it sit. See what your voltage is after the day and that will rule out the alt.


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[JeffP]

Hey
Thanks. I did steps 1 through 4. But I will try it again tomorrow. I was rushed and might have missed something.

I have been reading about the regulator today so I will look into that if my second attempt at steps 1-4 don't work the second time.
Thanks for your help.

I’m not sure if your Jeep’s charging circuit is fused other than a fusible link. If the problem is still there after pulling all the fuses then check the alternator. The field coil is energized when it shouldn’t be.
The idiots at the auto parts store won’t likely see that! Check it yourself!
If you can’t figure out how do do it with a meter... at least disconnect the alternator and see if the battery holds it’s charge.
Your battery should never discharge beyond 50%. Each time you allow that to happen, it’s lifespan is reduced dramatically.
Another note about parts store morons. They aren’t mechanics! Just like with fast food places... if you don’t follow the script, they can’t help you!
“I need a tire valve stem cap.”
“OK, what kind of car?”
“It doesn’t matter, there is only one size!”
“What engine do you have?”
“Are you retarded?”
“Is that two or four wheel drive?”
If your conversation was even close to that... your old battery was fine. They can’t test a drained battery! Even if they knew how... it’s their advantage to sell you one anyway! Besides, they don’t care if you waste money or if your car runs or not.

 

[Lumpy Grits]

Charge the batteries up.
Install'em and disconnect the 2 wire plug that's kinda near the back of your altenator. Reconnect after 24 hrs.
Will it start?
Shops only test alt. for amp/voltage output.
LG

 

[Munilover]

Charge the batteries up.
Install'em and disconnect the 2 wire plug that's kinda near the back of your altenator. Reconnect after 24 hrs.
Will it start?
Shops only test alt. for amp/voltage output.
LG

Thanks I will give this a try tonight.

 

[Munilover]

I’m not sure if your Jeep’s charging circuit is fused other than a fusible link. If the problem is still there after pulling all the fuses then check the alternator. The field coil is energized when it shouldn’t be.
The idiots at the auto parts store won’t likely see that! Check it yourself!
If you can’t figure out how do do it with a meter... at least disconnect the alternator and see if the battery holds it’s charge.
Your battery should never discharge beyond 50%. Each time you allow that to happen, it’s lifespan is reduced dramatically.
Another note about parts store morons. They aren’t mechanics! Just like with fast food places... if you don’t follow the script, they can’t help you!
“I need a tire valve stem cap.”
“OK, what kind of car?”
“It doesn’t matter, there is only one size!”
“What engine do you have?”
“Are you retarded?”
“Is that two or four wheel drive?”
If your conversation was even close to that... your old battery was fine. They can’t test a drained battery! Even if they knew how... it’s their advantage to sell you one anyway! Besides, they don’t care if you waste money or if your car runs or not.[/QUOTE

Should I grab the Optima battery charger, or is that a scam? I haven't charged the new batteries yet so I want to do it without decreasing their lifespan.

 

[JeffP]

I’m not sure if your Jeep’s charging circuit is fused other than a fusible link. If the problem is still there after pulling all the fuses then check the alternator. The field coil is energized when it shouldn’t be.
The idiots at the auto parts store won’t likely see that! Check it yourself!
If you can’t figure out how do do it with a meter... at least disconnect the alternator and see if the battery holds it’s charge.
Your battery should never discharge beyond 50%. Each time you allow that to happen, it’s lifespan is reduced dramatically.
Another note about parts store morons. They aren’t mechanics! Just like with fast food places... if you don’t follow the script, they can’t help you!
“I need a tire valve stem cap.”
“OK, what kind of car?”
“It doesn’t matter, there is only one size!”
“What engine do you have?”
“Are you retarded?”
“Is that two or four wheel drive?”
If your conversation was even close to that... your old battery was fine. They can’t test a drained battery! Even if they knew how... it’s their advantage to sell you one anyway! Besides, they don’t care if you waste money or if your car runs or not.[/QUOTE

Should I grab the Optima battery charger, or is that a scam? I haven't charged the new batteries yet so I want to do it without decreasing their lifespan.

While I use Optima batteries in all my Jeeps I haven’t tried the Optima charger myself... yet. I have heard great things about it, like reviving non-Optima batteries but nothing bad.
I have two heavy duty shop starter/chargers and several of the smaller 10 amp kind. So I don’t really need another. However “if” I did, I’d likely invest in the Optima charger as well.
I have quite a few classic cars. Obviously they don’t get driven often. Each is on a trickle charger “Battery Tender”. I’ve had extremely good luck with those. Even the Cheap Harbor Freight ones seem to work OK.
Bottom line... if you need a charger, get it.

 

[Munilover]

While I use Optima batteries in all my Jeeps I haven’t tried the Optima charger myself... yet. I have heard great things about it, like reviving non-Optima batteries but nothing bad.
I have two heavy duty shop starter/chargers and several of the smaller 10 amp kind. So I don’t really need another. However “if” I did, I’d likely invest in the Optima charger as well.
I have quite a few classic cars. Obviously they don’t get driven often. Each is on a trickle charger “Battery Tender”. I’ve had extremely good luck with those. Even the Cheap Harbor Freight ones seem to work OK.
Bottom line... if you need a charger, get it.

Great. Thanks . I will pick one up.

 

[JeffP]

Thanks I will give this a try tonight.

Depending on which style alternator you have, Ford or GM, you may need to disconnect the large, single wire as well.
The GM type has a large single wire going to the starter solenoid/ battery + and a small, two prong connector that goes to the ignition switch / idiot light. This type is “self exciting” so the field can theoretically be energized even if the key is off or the two prong connector is disconnected. Note the alternator will still charge if the two prong connector is disconnected after it exceeds 1,000-1,500 rpm once per operating cycle. The “idiot light” will be disabled if the two prong connector is unplugged.
On the Ford type, there are screw terminals for each connection. Since you can’t see how they are marked with the alternator mounted, just remove them all. Wait and periodically check battery voltage.... I suspect it will remain steady for the 24 hr test period.
Hope that clears up any confusion you may have. Bottom line don’t trust the morons at the parts stores! If lucky, 1 out of 20 knows what he’s doing.

 

[mtnwhlr]

And if you disconnect the big wire from the alt be careful because it will be hot.

 

[kingav43]

I know I am late for this but we had the same problem we took it to a dealer and found out it was just the https://www.fs1inc.com/jeep-ecu-ecm-pcm.html Jeep PCM that was dying and it was between paying 2k for it or just get it somewhere cheaper and we had to go with Flagship over carcomputerexchange due to the lifetime warranty offer and so far my baby is running smoooth!

 

[kingav43]

https://mintt.com/jeep-pcm/ Jeep PCM from mintt are much more cheaper than flagship one PCM and much more faster with shipping