Battery light on

[REF]

Did the original alternator have a separate plug in stator wire that clips in? What about the new one?

[Scalf77]

I got these from the manuals that @ScrapIron posted about a while ago "Free Basic Shop Manuals"

[IMG][/IMG]

Diesel, Single Generator

The diesel single generator system consists of the generator mounted on the top right of the engine. A 110-amp generator with a 2.79:1 pulley ratio is standard. An extra heavy-duty option is available which includes a 140-amp generator with a 2.79:1 pulley ratio. The generators are similar in appearance and use the same connectors, making them interchangeable. Identification between the different generators can be carried out by referring to the generator engineering number and the parts catalog.

In the diesel single generator system, with the key in the ON position, voltage is supplied through the charging system warning indicator (in the Instrument Cluster (IC)) through the I circuit to the voltage regulator. The regulator grounds this circuit and the charging system warning indicator is illuminated. When the engine is started, the regulator removes the ground on this circuit and the charging system warning indicator turns off.



You should have the power cable and connector for the two other wires go to Connector 1104A

[IMG][/IMG]

There are plenty of pin point test listed in the manual, but I would check to make sure the I circuit return Pin 1 was not shorted out to ground. I would also make sure that Pin 3 reads the is the return voltage from battery or power distribution.

[N147JK]

Do you have a spare alternator or the original alternator you can swap in temporarily? Step 1, I'd do that and see if the light stays out, seeing as that's the only thing you changed.

[kbeefy]

Since it only comes on after running I would not suspect a short. Also, the test I posted previously checking for the light illuminated with the alternator unplugged rules out or confirms a short.


In the description @Scalf77 posted above, there doesn't seem to be mention of an over-voltage situation, which is what the mentioned fault code is.


It might be possible that the ECU is monitoring a voltage that is different than the voltage you are seeing at the batteries. Your Alternator could also be getting a voltage reading elsewhere and adjusting it's charge output based on that.


Have you tried checking charge voltage at the post on the alternator while it's running to see what it ramps up to before and while setting the charge indicator and throwing the over-voltage code?


Also, have you tried disconnecting your house batteries and retesting?

[kbeefy]

I just reread this thread.... have you checked battery charge voltage, or is everything based on OBDII voltage? I often see my OBDII voltage different than what I measure at the battery.



There is also OBDII voltage and DTC connector voltage that can sometimes be different.

[kbeefy]

FWIW, I don't have to log back in to this forum each day, or ever.
I am posting from a desktop running windows, that might have something to do with it.

[Pntyrmvr]

I'll second the difference between PCM and alternator voltage. Different vehicle but the battery gets 0.7 volts more than the PCM reports.

[Otterboy]

Please keep in mind that “swapping out alternators” in this van is not a simple proposition. 5 hours shop time each time due to all the work required removing and returning stuff to complete the swap. That’s roughly $1k each time. The first and second new DC Power alternator triggered the light only after engine startup and idling for a minute or two. I will be returning to the shop Tuesday and will again call DC Power. The alternator is charging batteries and I’ve been reassured that no damage is being caused by driving with the light on.

[Otterboy]

Ps I am charging the house batteries and have a trickle charger on engine batteries. I want to see if having all 4 batteries fully charged makes any difference on the light. The shop contends that the problem lies in the feedback loop regarding voltage the pcm expects and what is reported.

[Otterboy]

Follow up. After conversations with DC Power and the shop, it appears the alternators shipped had the wrong voltage regulator for my van because mine is a pcm controlled voltage regulator unlike earlier models. Here is what DC Power had to say:

“After talking to the tech, he confirmed my suspicion. The van is potentially using a PCM controlled unit which would require an entirely different regulator. I'm hoping this would be the fix for this, as the catalog and part numbers for your alternator do not call for the PCM controlled regulator. Hoping it's just an incorrect catalog and this resolves the issue. The regulator will arrive tomorrow. “

My vin is 1ftse34p79da89266. Can anyone here enlighten me as to what to believe?

Shop advised I return to stock alternator which did a poor job of charging my 4 batteries but eliminate the battery light.