Auto mechanics, I need some troubleshooting help.

[flightsimmer]

I have a 2002 Dodge, Grand Caravan 3.3 Ci, and recently it has started to quit charging once in a while.


I pulled and had the alternator tested 3 times and it tested good.


The battery is 2- 2-1/2 years old but test very good.


You can start it up and drive just fine, then suddenly the battery light will come on. If you turn it off and then restart it, it will sometimes start charging again.


I'm hoping it is not the ECM because I cannot afford it at present.


Is there anything else that might cause this problem?


Thanks.

 

[printcraft]

Check and clean/scrape your battery connections.

 

[Bigtanker]

Alternaters do funny things before the completely quit. I had one on a Nissian the did the same as you. I hooked up a volt meter to it and while driving down the road, it would quit charging. After a few miles, it would start again. My guess it the alt is on the way out but there are a few other things to check. Make sure the belt is in decent shape. The belt tensioner could be weak causing the belt to slip.

I really doubt it's the ECM. They don't have anything to do with the charging system other than to monitor it.

 

[Fargo]

The exciter wire might have a loose connection.

 

[churchmouse]

I have had an alternator failure that acted this way under a heavy load before it failed.

Are you running a the A/C full tilt when this happens. That is a solid load on the charging system.

 

[Salty]

If that is the original alternator I would guess that the brushes are just about worn out.

 

[eldirector]

Those have an external voltage regulator. Check all the connections between it an the alternator, and then it and the main fuse panel. Pretty cheap to replace, and easy.

 

[Arm America]

I second the belt tensioner.

 

[x10]

BTW on Some chrysler models all the way back to at least 98 the ECM does control the charge on the Alternator.

All the stuff talked about is possibilities considering it's a 02 bunches of stuff can be happening

 

[SMiller]

Check all contacts and ground cables, star with the free and easy stuff.

 

[awames76]

most newer alternators are ecm controlled aka externally regulated, an 2001 dodge Dakota is externally reg. on it it would stop charging, if u took the plug on the back and move it kinda hard it would start charging. the alt was on its way out with 140,000 miles. on my 2001 gmc sierra it lasted 295,000 miles before it quit.

have them check the alt while its on the van. had a buddy have a starter go out on his truck . he took it off and it tested good but it was still bad.

 

[churchmouse]

Get a good D/C volt meter.
Start the truck. Turn on the AC to Max and High fan. Headlites as well.
Check the voltage at the battery posts.
It should be a steady 13.5 + under a load.

 

[Cameramonkey]

Have you changed the alternator fluid recently?

 

[churchmouse]

Have you changed the alternator fluid recently?

Only the bearing fluid not the pulley fluid.

 

[bacon#1]

Remove said battery, clean posts, install in anything other than a dodge........

 

[Leo]

If that is the original alternator I would guess that the brushes are just about worn out.

+1 If it is not charging, and a good rap with a hammer makes it charge for a few moments, brushes are a safe bet.

My memory is fading, but I think the 2002 still had external regulators. Three conductor cord running to it on the drivers side inner fender. Past the mid 80's they were sealed throw away regulators, but cheap.

 

[BiscuitsandGravy]

Start with cheaper part (reg) then work your way up (alt). Test it under full load while hot for failures.

 

[churchmouse]

Start with cheaper part (reg) then work your way up (alt). Test it under full load while hot for failures.

Post #12

 

[GodFearinGunTotin]

I have a 2002 Dodge, Grand Caravan 3.3 Ci, and recently it has started to quit charging once in a while.


I pulled and had the alternator tested 3 times and it tested good.


The battery is 2- 2-1/2 years old but test very good.


You can start it up and drive just fine, then suddenly the battery light will come on. If you turn it off and then restart it, it will sometimes start charging again.


I'm hoping it is not the ECM because I cannot afford it at present.


Is there anything else that might cause this problem?


Thanks.

I don't have an answer but does it do it with no load or little load on it? Teeing off CM's post, does your light come on if you leave the lights, AC, HVAC fan, etc. off? Does it only do it if the AC's on? See where I'm going? Still though, if you turn all that stuff on and you don't have 13-14VDC at your battery, it's telling you you've got an alternator problem of some sort.

Also, have you googled this issue for your particular vehicle? Chances are, especially if this is a common problem for your car, someone's already posted about it and what they did to fix it---and probably with a handy YouTube video.

 

[halfmileharry]

Testing is a good thing but you'll need to simulate a full load on the alternator to see if it has a short, bad diodes, or regulator. I'm guessing Diodes but I can guess 'til the cows come home without having hands on.
Oh, the testers are only as good as those people using them. I gave up on AutoZone, O'Reilly, etc.
There is a girl at the O'reillys on Madison Ave just south of Southport rd I'll trust with any test equipment. She's good. Not many around with her skill set.