Jeep Wrangler Forum

Jeep Wrangler Forum (http://www.wranglerforum.com/)
-   TJ Tech Forum (http://www.wranglerforum.com/f210/)
-   -   Help with electrical. Is it Battery or Alt or ??? (http://www.wranglerforum.com/f210/help-with-electrical-is-it-battery-or-alt-or-49789.html)

ctrangie 04-28-2010 07:58 AM

Help with electrical. Is it Battery or Alt or ???
 
Hi Guys, please help. I suck at electrical.

I've got a 97 tj ( 2.5/ stick) It's had a few minor shorts or bad grounds over the years, but nothing major.

Most weeks I only drive it a total of 20 or 30 miles with quick in town trips. Over the winter the battery was low or dead a lot and I often needed to hook up the the charger to get going in the mornings. I figured the battery is getting a bit tired (3-4 years), it's cold and I don't drive it enough to give it a good charge. Always runs fine once it gets started so I didn't think it was the alt.

It has been better, but acting up a bit in the warm weather now too. Had to jump it yesterday. I left it on a charger overnight and it fired right up this morning, but then after about 3 minuted the battery gauge went from 14-15 where it always is, to to the top of the dial. 2 minutes later it went back to normal. 2 minutes after that it was back to overcharging.

Is this a sign of a bad alt or regulator? Or can it do that because the battery isn't charging and the power has no place to go?

Thanks.

Neil F. 04-28-2010 08:40 AM

Take the vehicle to Pep Boys, Autozone or other and they will check the battery and alt.

stevens243 04-28-2010 09:31 AM

That sounds like the battery. If you don't want to drive the jeep to pep boys or wherever, just take the battery.

Most places that sell batteries will check them for you. If it's bad, buy a new one and put it in there. Should solve the problem.

jerryj 04-28-2010 09:45 AM

Get it started and disconnect the battery if it dies you need a new alternator if it runs your usually ok.Sounds like the battery.Also make sure all the cables are tight on all ends.

flash19901 04-28-2010 01:36 PM

Here ya go. The battery has 6 cells. a fully charged battery should have 2.1 volts per cell. Ideally 2.2. But a fully charged battery should read 12.6 volts or more. If it reads 12.4, that's a three quarter charge. If 12.2, that's 1/2. 12.2 is 1/4. With a volt meter or a load tester, check the voltage of the battery.

If it has been recharged and is reading 12.6 or more then you can test it. If it won't charge more than 10.5 then you have a bad cell and it needs to be replaced. If you have a load tester, note the cranking amps on the battery. hook up the tester, check your charge (12.6) and then flip the switch. The needle should stay in the green or MAYBE dip into the yellow. Release after ten seconds. If the battery stays there under load and pops back into the green when the toggle switch is released then the battery is good. If it dips into the red and comes back up then the battery might be weak. If it stays down with this simple load test, replace it.

With the battery in the Jeep with the motor running it should read 13.8-14.2 volts. This means you charging system is fine. If it reads significantly less then it is something in the charging system other than the battery.

Jerry Bransford 04-28-2010 01:40 PM

Quick charges in the morning are never enough to fully charge a battery and the same thing with short trips. Before you waste any more of your time, put it on the charger all night and see how it does in the morning. If that doesn't take care of the issue, then take it into a battery dealer and have them do a load test which is the only way to know your battery's true health.

nick50471 04-28-2010 01:46 PM

Quote:

Originally Posted by ctrangie (Post 610779)
Hi Guys, please help. I suck at electrical.



I left it on a charger overnight and it fired right up this morning, but then after about 3 minuted the battery gauge went from 14-15 where it always is, to to the top of the dial. 2 minutes later it went back to normal. 2 minutes after that it was back to overcharging.

Is this a sign of a bad alt or regulator? Or can it do that because the battery isn't charging and the power has no place to go?

Thanks.


Jerry he tried that. Taking jeep to parts store to test battery is the best advice.

Jerry Bransford 04-28-2010 02:05 PM

Quote:

Originally Posted by nick50471 (Post 610987)
Jerry he tried that. Taking jeep to parts store to test battery is the best advice.

Oh crap how did I miss that, thanks. You are right, it's time to take it in to have it load tested.

Bobthegod 04-28-2010 05:21 PM

I figured the battery is getting a bit tired (3-4 years),

If you have a battery that's 3-4 years old then first check the life of the battery. Some are 24 months, some 36 months some 5 years. What does it say on the battery? That's the easiest test of all. If you have a 2 year battery and it's been 3-4 years DUHHHH you need a new battery.

flash19901 04-28-2010 06:54 PM

Not ncessarily on the life of the battery thing. I had an OE Champion that lasted 9 years. I once sold a Douglas that lasted 15. I sold a battery last month that came back later that day and was indeed a bum.

If you take the Jeep/battery to a parts store, make sure you take it to one that has a couple of racks of OLD catalogs on the counter. You know the guys have been there for a while and know the difference between a headlight and a taillight.

Jerry Bransford 04-28-2010 07:38 PM

Quote:

Originally Posted by flash19901 (Post 611297)
If you take the Jeep/battery to a parts store, make sure you take it to one that has a couple of racks of OLD catalogs on the counter. You know the guys have been there for a while and know the difference between a headlight and a taillight.

Hah how true. I stopped by my local Autozone a few months ago to see if they had a pinion nut I needed. Of 4 guys working in the store, none knew what a pinion nut was. To make it even worse, I got the same blank stares when I explained that it was the nut that went on the pinion gear shaft. No kidding, they didn't even know what a pinion gear was. Autozone, what a joke. :rofl:

flash19901 04-28-2010 07:45 PM

Did you know that 83 Camaro's and 89 Dakota's do not have wheel bearings? Apparently the Zone's vendors have finally perfected that Mag-Lev system of conveyance.

rrich 04-29-2010 12:56 AM

What else would you expect from an ex-burger king onion chopper?

Keeping a battery at low charge, especially in the cold, then recharging every so often to use it definitely shortens a battery's life.
You may have killed it by now.
Most batteries can take one discharge, but more than that they become unreliable.

But seeing the voltage jump up for a moment, then back down, can indicate a bad cable connection - clean and tighten BOTH ENDS of BOTH battery cables

If it isn't the cable connection it's inside the battery - replace.

NEVER disconnect the battery to see if the engine still runs as a test - it can kill an alternator, or worse yet - your ECM.

That old time test was valid when we had generators, not modern electronics.


All times are GMT -5. The time now is 09:52 PM.