HELP - On the road - battery light popped on, 11.7v running

AHAMAYfrank

Ordered03, Owned04, Now07
I see this is an old thread but I have a similar charging issue on my 2007 2500. I searched Charging and ended up here.

The red charge system warning came on heading home from work one day as well as the air conditioning blowing warm, the radio turning off, and illuminating just about every light on the dash at one time or another. I got home but couldn't put the windows up until turned off the truck.

At the battery my system shows 12.4 volts off and slightly less running, at the battery and at the output terminal on the alternator. I didn't check at the alternator until I replaced it with a new one. I can't find anyone in the area that can bench check the alternator. (broken machines, missing cabling, unable to mount this style alternator).

If I check voltage at the small wire IN to the alternator I get battery voltage until the van starts and then I get 9 volts DC. After turning off the truck it remains at 9V until the high pitch tone stops and then it goes back up to battery voltage. The high pitch sound is the one I have been wondering about since 2007 when my van was new.

Does the fact that I appear to have no output at my new alternator imply that my Y chord is not the issue (but probably should be replaced any way?) Any insight is appreciated.

Frank S.
 

autostaretx

Erratic Member
It's quite possible that your "small wire" is not a classical DF (dynamo field) driver, but a computer-messaging LINbus.
(newer NCV3s certainly are)

Therefore simple voltmeter testing is almost completely useless. (it does show messages are being sent, but not what they're saying)

--dick
p.s. the "rising to 12v when off" is a supporting clue.. that would be the effect of "pull-up" resistors typical on such a bus

p.p.s. the "9v when running" is merely the time-averaging of the zeros and ones being passed as messages.
 
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smiller

2008 View J (2007 NCV3 3500)
As above, the small wire is a LIN data line so the voltage there will be meaningless. As you know the Y cable would always be suspect in a case like this but isn't the issue if you are not seeing the proper voltage at the alternator output. You are measuring right at the output terminal on the alternator, right?

The whining sound you hear for a minute or so after the ignition is turned off is an EGR valve cleaning routine, and is normal.
 

AHAMAYfrank

Ordered03, Owned04, Now07
Thanks for the replies.

Yes I was checking voltage at the output terminal on the alternator. Battery voltage not running and a little less than that when running.

I am reluctant to take my truck to the Mercedes dealer, about an hour away, to read codes. My only experience there was not a good one. "After reading the diagnostic codes for $165, the recommendation was to Replace all Glow Plugs $868, Replace Glow Plug Output Module $601.88, and Program Glow Plug Output Module $229.99 for $1699.87 total. I ordered a GP Output Module from AutoZone for $229.99 that comes with a lifetime warranty." After a few start / stop cycles my glow plug and check engine light stayed off. I got the Autozone part tip from a thread I started here. :thumbup:

I took the truck to Autozone now and the only light on the dash is the red charging failure screen. No check engine light or glow plug light. They were able to get Error Codes P0670 through P0676 related to the glow plug module control circuit and all 6 cylinder glow plug circuits. Each of those was there twice (13 total). In addition they got U0423 Invalid Data Received From Instrument Panel Control Module just once, so actually 14 total.

After driving into town and back I still have just the battery charging system red screen with no other failure indicators.

Thanks, Frank
 

showkey

Well-known member
With the battery in a low state of charge and the alternator light on...........you will get a literally dozens of codes appearing. Every system on a Sprinter is sensitive to low voltage and will throw codes. Anything short of 13.8-14.2 Volts with the engine running can create false codes.

Concentrate on the fixing the charging system. As you seem to already know the alternator and the Y cable and wiring are the common suspects.
 

bcislander

'07 Mercedes-badged Dodge
snip....
Does the fact that I appear to have no output at my new alternator imply that my Y chord is not the issue (but probably should be replaced any way?) Any insight is appreciated.

Frank S.
The Y-Cable and ground strap connections are well-documented charging system failure points in early NCV3s.

Before wasting any more time 'scratching your head', just replace the Y-cable with the latest version and check that the ground cable is in good condition and the attachment points are clean.

Report back after changing the Y-cable, etc,
 

AHAMAYfrank

Ordered03, Owned04, Now07
Well it appears I am the latest victim of the early Y chord blues. I replaced the cable with the latest greatest today and now within a few seconds after startup, I have voltage climb to above static battery voltage at the battery and at the alternator output terminal.

Thanks to all that participated in this discussion. :bow: It seems that what I would consider "normal" charging system checks, do not apply here. :thinking:

Glad to be on the road again.

Frank S.
 

AHAMAYfrank

Ordered03, Owned04, Now07
Well it appears that my euphoria was short lived. :thinking:

I don't drive my sprinter much when the sun is shining, so I really only have less than a couple hundred miles in the last few weeks. My first trip was ok, round trip to work is about 50 miles. After sitting a while my next trip, to work of 25 miles was good, but upon start up leaving work the glow plug and check engine light stayed on and then a short time later the red battery charging system message appeared in big bright letters.

I again checked the voltage across the battery when I got home and I have about 14 volts or so. Wondering again about my battery conditions possible contribution I applied 2 amps unregulated charge for a couple days. Today's ride was uneventful with the charge light and check engine light on with the glow plug light going off within a few minutes of start up.

Tomorrow I with again check voltage across the battery with all the electrical goodies running to see if I might be missing something.

Frank
 

lrcasella

Member
Y-Cable failure on the older Dodge Badged V-6 (2007 - 2008) Sprinters, especially on motorhomes because of the extra current draw to coach batteries, are very common. However, they never turn on the Alternator light since that is sensed at the alternator terminals. In your case, it seems the high current draw from the cable caused the failure of the alternator. The other point, you said he put in a 220 amp alternator? I haven't seen too many 2500 vans with the 220 amp alternator - usually the 180. They are an option that year, usually on 3500 cutaways for Motorhomes. My understanding is you can not upgrade the size of the alternator. So if you have another new 220, and original was 180, be prepared for more issues. Datacard, as mentioned on another post, has the size of the original alternator.
 

AHAMAYfrank

Ordered03, Owned04, Now07
I have unbolted my grounds and first wire bushed and then used contact cleaner before reassembly. I will confirm that the replacement alternator I installed is the same as originally installed in Germany. I know I did not buy a 220 amp as they were only available new and I got a refurbished one.

Interesting that I now have 14V output at the battery and at the alternator connection when with the old y-chord I did not.

Frank
 

bcislander

'07 Mercedes-badged Dodge
I have unbolted my grounds and first wire bushed and then used contact cleaner before reassembly. I will confirm that the replacement alternator I installed is the same as originally installed in Germany. I know I did not buy a 220 amp as they were only available new and I got a refurbished one.

Interesting that I now have 14V output at the battery and at the alternator connection when with the old y-chord I did not.

Frank
14V at the battery after replacing the Y-Cable and cleaning the ground connections is not 'interesting', but what you should expect with a working alternator.

In fact, I would not be surprised if your 'old' alternator was still OK, and your charging problems caused solely by the Y-Cable and/or ground connections.
 

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