CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

2003 Jeep Liberty battery light, and separate issue wouldn't turn over

I went to the store a couple weeks ago and when I came back out my 2003 Jeep Liberty would not start. Would not even turn over. Just as if the battery were completely dead, but no clicking sound or clattering sound. All lights and accessories worked. I just got a brand new battery about a month ago. Tried jump starting it just in case, even tho accessories worked, but that did not work. I had to leave it sit in a parking lot for 3 days before I could take it to a mechanic. Tried starting it every single day and still had power for lights, etc. But no power, would not turn over. Towed it to the mechanic and tried starting it when I got there. Same thing. Mechanic called me later that afternoon and when he tried it it started right off no problem whatsoever. He said there was nothing to check because there were no warning lights on and no problem. Have not had any starting problems with it since then.
However, a week or two later my battery light came on. Everything seems to be working fine and when I shut the Jeep off and turned it back on, the battery light went off and stayed off. And it had been off for about a week since.
Yesterday I was driving and the battery light came back on again. Within about 5 minutes the check engine light came on. When I shut the Jeep off and turned it back on again the battery light was off. But check engine light was still on. I decided to drive back home, because I was on my way to South Dakota from Wisconsin and did not want to get stranded. Within about two miles of driving the battery light came back on. Check engine light was still on at this time.
I took it to a friend who checked it with a computer, I did not shut the engine off when I got there so warning lights stayed on. Code was P1491, so my friend replaced the FAN RELAY.
I drove 600 miles today and everything was fine. 15 miles before I got to my destination the battery light came on again. When I parked it and started it back up again the battery light went off and has not come back on yet. It might be coincidence, but the battery light came on with a warning ding sound at the same moment I turned on the fog lights. Like I said this might be total coincidence. Nothing is dimming and all power seems okay. Cannot figure out what’s going on. Any thoughts??

The battery light indicates a charging system failure. Have the alternator tested, preferably when the warning light is on as there could be an intermittent failure.

As @Nevada_545 said, the battery light illuminates when the alternator is not charging the battery. Alternators can start to do this sort of thing when they begin to die. What usually occurs is that the brushes inside the alternator wear down and make intermittent contact with the rotor inside the unit…when this happens the output of the unit goes from normal to zero and back and forth like this until one day it just fails completely. This is what causes the charge light to turn on and then off again.

I’m not sure how involved you want to get with this, if you had a multi-meter you could witness the output of the alt when it is working and then also when the charge light is illuminated etc… You could also buy a rebuild kit for this alternator and rebuild it yourself. Its not difficult at all really depending upon the failure mode…and yours is more than likely the brushes being worn down, inside the alternator… OR you can skip all that fun stuff (I personally find it enjoyable) and just install a new unit…or have one installed.

A new alternator should fix you right up…pretty easy.

1 Like

Thank you for the ideas. My boyfriend thought of the alternator, but when the code indicated replacing that fan, we thought that was that. He and a buddy checked the voltage before and after and it was doing the correct volts after replacement. Sorry for the not-so-techno terminology on my part.
When I first had the issue with it not turning over, we thought alternator as well. When it started at the mechanics place, he told me he could not test the alternator because everything was working and testing wouldn’t show him anything. Was he just misinformed??

He could test the alternator but it would have likely tested good at the time, you had the vehicle towed to the shop for a starter problem.

Now that the charging system warning light is on have the alternator tested.

I presume when you say it won’t “turn over”, you mean what mechanics call a “no-crank”; i.e. you aren’t hearing that rrrr rrr rrr sound like you normally do with the key in “start”. That combined with the alternator warning light coming on and off and diagnostic code for the fan when there’s no problem with the fan makes me think you have a loose connection in the main power circuitry somewhere. The computer is probably getting confused b/c its voltage input is varying too much, or is borderline, at times barely enough to keep it running. On a 2003 excellent chance the problem is the connection from the battery negative to the chassis ground, or from the engine ground to the chassis ground. Corroded, rusty connection points are a common cause of that. You might have battery cable problems too. They can corrode inside the insulation so they look ok, but in fact the copper inside is in the process of disintegrating. You could try wiggling the battery cables with the engine idling, see if that has any effect on the warning lights. Cracked or otherwise defective high current fuses, another possibility.

A good diy’er test for battery/alternator performance is easy to do, requires only an inexpensive DVM, and is something you can use to evaluate your progress. Before the first start of the day the battery should measure about 12.6 volts. Immediately after starting the engine, 13.5 to 15.5 volts.