96-97 Dodge Caravan Charging problems-Alternator ?

[mene]

Originally Posted By: crazyoildude
He is not great with fixing cars he is ok but says his friend is pretty good, my thinking is if it's not the alternator it may be the ecm i told him i believe its on the drivers side but im hoping its the alternator. Im pretty sure if he even finds a good ecm it has to be programmed and he will have to take it somewhere for that anyway. He did say the wires that plug into the back looked a little corroded so who knows he is far away.


Tell him to watch this video https://www.youtube.com/watch?v=CImyX5KuGvQ and there are others similar to this about fixing that alternator, tell him to check the brushes, I really doubt is the PCM, and you can use a non reprogrammed PCM in the van as long as " his van has no factory immobilizer and the replacement neither" needless to say that the used PCM should come from a van with identical equipment and that if he has to smog the van for registration it will come up. The PCM is sandwich between the battery and the body, the battery has to come off and the fuse box loosened the 2 10mm bolts and hinged back then 3 10mm bolts hold the PCM in place, two in the top and one in the bottom, most of the time one or more rust inside the casing and shear off, Mopar sell them in a bag of 3 but if you ask they will sell you a single one, the issue then is to drive the bolts out of the PCM without damaging the case. Again I doubt is the PCM.

 

[doitmyself]

Originally Posted By: crazyoildude
He is not great with fixing cars he is ok but says his friend is pretty good, my thinking is if it's not the alternator it may be the ecm i told him i believe its on the drivers side but im hoping its the alternator. Im pretty sure if he even finds a good ecm it has to be programmed and he will have to take it somewhere for that anyway. He did say the wires that plug into the back looked a little corroded so who knows he is far away.


This thread is a good example of how us diyer's (me included) fail by making assumptions and swapping parts. My son wasted $150 on his Ranger last month on a new alternator only to learn that a field wire from the alt. to the PCM had rubbed through and broke.....Under $5 in parts to fix.

Visual inspection of wires doesn't work.

Check the battery.
Check the grounds.
Check the main charging wire and its fuse/link.
Check the alt. to pcm wires.


After this, THEN start considering the alternator or PCM. If this guy has no multimeter and general auto skills, I'm not sure how he can be helped without spending $$.

 

[doitmyself]

Here's an example of how a diyer diagnosed that his '97 Caravan PCM was bad:

http://www.dodgetalk.com/forums/showthread.php?t=229182

Best wishes on a simple repair.

 

[HerrStig]

With 140k the "lucky" fix could be new brushes, at less than 15 bucks. Check the wiring first. . I hope the alternator is not buried and hard to get to. If you can get to the back of must Denso units you can swap brushes right on the car. When alternator bearings start to fail, usually from overtightning the belt, the resulting wobble in the rotor will take its toll on the brushes.

 

[Thermo1223]

My Dad's 2000 GC had a bit of a wonky charging issue. It would sit for a bit and then proceed to pulse the lights on the next start as it started charging. It would sit maybe 2 weeks max between use. I borrowed an older Snap-On Scantool and narrowed it down to not the Alt/Battery/PCM but a bit corroded Neg. Cable and some dirty grounds.

I could force the field to full on and it would be fine but never actually go above charging spec. Technically by what I read it should have gone over 15V. but it never did. Clean the connections and it stopped pulsing and started charging normally.

So lessen learned with Chrysler products never assume it was the alternator like I almost did.

 

[HerrStig]

THe "old" pre GM SAAB 900s had the engine in "backwards" and the alternator on about a foot and a half long bracket, which was the only ground path. Many a SAAB of that vintage had an "aftermarket" ground wire added, right to the block. The one good thing about having an engine back to front was the back of the alternator was right there where it could be serviced.

 

[Vikas]

Can anybody explain the reason why the light would come on only after 1 minute of running? Can he confirm that for the first minute he is seeing around 14V coming to the battery and then suddenly drops to under 12.5?

Isn't remote diagnostic so much fun?

 

[crazyoildude]

i was thinking the same thing and he did not check for voltage at that time according to him. Im hoping its just the alternator but it sounds more like the regulator the more i think about it. I know he has other issues for years that sounds like the computer anyway. Sometimes he tries to start it and it just cranks so he turns off the key or unplugs the computer for a few seconds and it starts up so im pretty sure the ecm should be replaced. When that happens he says it throws a po340 according to someone who helped him scan it.

 

[Oldmoparguy1]

Originally Posted By: crazyoildude
This vehicle is in Florida and i am here in NJ it belongs to a friend of my sisters. He called me this morning and said his alternator light comes on after about 1 minute and his battery is not charging (He said he tested it with a volt meter) so i told him since his battery is only about 6 months old it sounds like the alternator so him and a friend took the old alternator out and took it to an auto parts store (maybe Auto Zone) and they put it on their alternator machine and said it passes all the tests and the unit looks good. I told him a few minutes ago that he should replace it anyway because the test they did was only about 30 seconds and maybe the test was not long enough.. He thinks the alternator is original with over 140,000 miles on it. Anyone agree with me or am i missing something and if so any ideas? Im not sure if it is a 96 or a 97 but it is a 3.3 according to him.


That's easy, the brushes are worn down to a nub. Common failure. The brush blocks are cheap and easy to replace. $12-$15. I've done 2 of mine and have 2 spares to do when I get around to it. The slip rings will be grooved and will need to be turned a little and polished. I did mine using a drill motor to spin the rotor and a fine file to cut the copper slip rings.

Wayne

 

[Oldmoparguy1]

Originally Posted By: crazyoildude
i was thinking the same thing and he did not check for voltage at that time according to him. Im hoping its just the alternator but it sounds more like the regulator the more i think about it. I know he has other issues for years that sounds like the computer anyway. Sometimes he tries to start it and it just cranks so he turns off the key or unplugs the computer for a few seconds and it starts up so im pretty sure the ecm should be replaced. When that happens he says it throws a po340 according to someone who helped him scan it.


There is no regulator. The ECM controls the alternator directly. You can have all sorts of odd symptoms with that generation of hardware/software. The ECM fault detection wasn't all that reliable. Mopar Alternators of that vintage were throwaways, Chrysler wouldn't provide repair parts. Sometime in the near past, China jobbers saw a market and filled it. The stuff I bought looked like OEM and fit perfectly.

Wayne

 

[Merkava_4]

I'm still waiting for a reply from you crazyoildude. You should say "No Thank You" or "Go To [censored]" or something.

 

[crazyoildude]

Im sorry i did see your post and did not mean to be rude. I would like for you to e-mail thatif the offer is still good i am always looking for something to read. By the way they called me tonight and said it was the alternator like i originally thought but i still have that pcm in the back of my mind. Auto Zone clobbered him around $140 for the alternator a part i would have paid $80.00 for through auto zone commercial with a lifetime warranty but also said it looked like the build quality was the best he had ever seen (looked brand new) so he was very happy. I will post any new information if i hear any. Merkava email that to me and thank you!

 

[Merkava_4]

You're welcome, but I still need some kind of an e-mail address to send it to whether it be your brother's, your sister's, or even your mother-in-law's. Preferably Gmail.