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battery light on?

5347 Views 7 Replies 5 Participants Last post by  ohcdoug
I have a 1998 grand caravan, 3.3L motor, 1 week old new battery. just drove 8 hours straight no issues at all, all highway at 100k , sweet smooth drive until getting to hotel and the dash battery/charging system light goes on.
I checked battery connections, serpentine belt isn't new but still seems to have sufficient tension . Alt case has a small crack in the housing but no breakage. If I was home I would change out the alt but am on vacation for the next week...Can Tire is open 9 am tomorrow ...not the best place but what I have...trouble codes in PCM I will have them check and I have looked for a lose ground from the alt to the van, I have checked battery terminals and they appear tight and clean. I do not want to destroy the new battery driving to the next city so any ideas would be most helpful before can tire gets to look at it, they always do better if I give them a bit of direction.
So I need a bit of help soonest please!!

Thanks , Doug
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To properly diagnose you'll need the charging system checked. As far as visually checking the connections, you'll need to do more than that - remove the connections, clean and tighten. Connections can "look" fine, but there could be enough resistance to cause problems. Off hand though I would suspect a failing alternator. Don't know that I would trust the codes at this point. If the battery has discharged due to a faulty alternator the low voltage can cause all kinds of weird off-the-wall codes.
If the alternator housing is cracked, chances are that the internals are damaged.
You want at least 13 volts across the battery terminals at idle. The battery light is turned on by the PCM and a fault code is stored. The voltage regulator is also part of the PCM.
You may be able to retrieve the code yourself (see video). A P1682 would be a charging (alt field voltage) issue and needs immediate attention, but like a P0516 could be a battery temperature sensor fault would not adversely affect charging and the vehicle could still be driven.
I have found batt temp sensors left unplugged or damaged after a battery change if it is part of the batt tray. 2006-09-01_143757_1.gif
The minivan's plastic ambient/battery sensor may be under and behind the front bumper where it is easily bumped. 2009-07-15_022904_812c068a.gif
See if any 'P' code shows up during the instrument cluster test. Write it down.
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thanks for the replies guys!
I am myself of the opinion that its the alternator as well . I had no idea that there is a temp sensor for the battery, there was nothing in the tray but the tray when I replaced the battery myself 2 weeks ago. all the battery connections are tight and clean as new, but I will crawl under in the parking lot before I trek to ctc. This vacation I brought no tools at all . of course right?!

Strange how 8 hours of driving gives no lights at all, 2 stops for gas and lunch and coffee, only when we gor to the hotel at 10 minutes after ctc closes....painful.

Did get 33.89 mpg at least on the first tankful, something good at least.

you all have been very helpful, my thanks, I will post what it turns out to be.


Bob Lincoln said:
If the alternator housing is cracked, chances are that the internals are damaged.
cracks are very very small, in the "fan" part of the housing, not good to see but don't appear to affect the integrity of the housing.
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So I just crawled under the van in the hotel parking lot...I have no temp sensor under the front bumper, wiring pigtail yes but no sensor. I have no wires at all going underneath the battery mounting plate so no sensor there either.I looked hard at the alternator and said a few choice words to it and then started the van...let it run for 5 minutes and NOT BATTERY/CHARGE LIGHT CAME ON!
Still planning to get the charge system checked as soon as ctc opens but maybe not buying a new alternator now ...hoping anyway. And I will have them check trouble codes.
again thanks for the help, wish me luck!

A few years ago my wife had a similar situation with our 02 GC on her way back from Kentucky to NJ. In West Virginia the battery light came on. She pulled into a local garage and they found the radiator cap had come loose allowing coolant to spill onto the serpentine belt causing it to slip. They washed the belt, refilled the radiator, reinstalled the cap and all has been fine since then. They didn't want to charge her but she gave them some money for being so helpful.
So...the battery light comes on again after the van is loaded and we are ready to leave for 8 hours or driving to the next destination. I was going to ctc anyway for a test and now need likely a new alternator. The store opens at 9am and I am first in line, they have 2 that fit in stock and I take the largest amperage one as thats what looks like is on the van already. Only $260.00... for the part not labor as its a sunday tech are working at all...only service writers ???( what the utility of that is I will prevent myself from saying !!!)
I have a socket set and some experience doing this, they quoted me minimum $140 and an hour and a half ,at least he said...I got it done in 2 hours, only having to buy a 15mm combination wrench ( actually on sale yet!) and a long flatblade screwdriver, less than $12.00 in total.
The alternator casing upon taking it out is not only cracked a bit on one side , the underside( unseeable of course ) is cracked extensively, leading me to believe that the piece likely was rubbing internally, as it makes a grinding noise when I spin it in hand. I guess after 345,000 kilometers it just wore out.

Anyway, got it done and drove 8 hours with no issues at all in storms ( full lights, wipers and blower ) , and bought a new serpentine belt, as you know what happens when you "touch" something and its old ( likely +100,000 k on the belt), you will need to replace it soon,..which I can as I now have a long 15mm combo wrench that will stay with the van, that fits the belt tensioner bolt to allow belt removal. I do like to be prepared if I can.

Kudos to the Regina, Sask. CTC parts guy named Victor, great humour and great attitude and he even came out to make sure I was having no install issues and let me try as many wrenches as I needed with only having to pay for the long 15mm one.If you have to replace an alternator in your caravan ina parking lot do it there lol!

Thanks to all who read this and cared enough to reply!

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