Voltage Issue, 17911 Voltage Signal

I have searched.

Had the intermittent battery charge light come on, and following a good write-up on here, changed the pulley. It seems that issue is gone for now.

I erased all of the engine codes and got the below (17911 Voltage...)Now when measuring the voltage across the battery terminals, it measures 12.3-12.4VDC, at idle and at 3000 RPM.

Per the search threads, the wires from the alternator seem to measure 0 resistance from the alternator to the connector pins under the battery. Tested per a thread suggestion. The voltage regulator was removed and the brushes stick out only about 6-8mm from the brush holder and were not smooth in operation. They were cleaned with contact cleaner and are smooth, but are still only 6-8mm long. Could this be my problem?

On the two pin connector, should there be voltage between the pins, or voltage pin to ground? Or should this not be tested in this manner?

The car is new to me and I do not yet have the Bentley for this MK4,it is on order.

The Autoscan:

VCDS
Windows Based VAG/VAS Emulator Running on Windows 7 x64
VCDS Version: Release 15.7.4(x64) Data version: 20160216
www.Ross-Tech.com
Dealer/Shop Name:
Workshop Code: 000 00000 000000
Self-Diagnosis Log
Saturday,23,July,2016,14:49:52:23395
VIN: 3VWSP69M42M011724 License Plate: ASDFGFGHHJ
Mileage: 569930km-354138mi Repair Order:
Chassis Type: 9M (9M - VW Jetta IV (1998 > 2014))
Scan: 01 02 03 08 09 15 16 17 19 22 29 35 36 37 39 46 47 55 56 57
75 76
VIN: 3VWSP69M42M011724 Mileage: 569930km-354138miles
-------------------------------------------------------------------------------
Address 01: Engine Labels: 038-906-012-AGR.lbl
Part No: 038 906 012 FD
Component: 1,9l R4 EDC G000SG 4102
Coding: 00002
Shop #: WSC 00066
VCID: 57B774EAB55607866F-4B00
3VWSP69M42M011724 VWZ7Z0A3842382
1 Fault Found:
17911 - Load Signal from Alternator Term. DF
P1503 - 35-00 - Implausible Signal
Readiness: 0 0 1 1 1
-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 1C0-907-37x-ABS.lbl
Part No: 1C0 907 379 C
Component: ABS FRONT MK60 0103
Coding: 0004097
Shop #: WSC 00066 000 00000
VCID: 2A51FD1E86A44A6E00-513C
1 Fault Found:
00668 - Supply Voltage Terminal 30
008 - Implausible Signal - Intermittent
-------------------------------------------------------------------------------
Address 15: Airbags Labels: 6Q0-909-605-VW5.lbl
Part No: 6Q0 909 605 F
Component: 04 AIRBAG VW6 0202 0004
Coding: 12340
Shop #: WSC 00066
VCID: 3A71CD5E2604FAEE70-5102
1 Fault Found:
00532 - Supply Voltage B+
07-10 - Signal too Low - Intermittent
-------------------------------------------------------------------------------
VCDS
Self-Diagnosis Log
Saturday,23,July,2016,14:49:52:23395
Page 2
VIN: 3VWSP69M42M011724 License Plate: ASDFGFGHHJ
Address 16: Steering wheel Labels: 1J0-907-487-A.lbl
Part No: 1J0 907 487 B
Component: Lenkradelektronik 0002
Coding: 00008
Shop #: WSC 00066
VCID: 3065EF76F07830BECE-51D0
No fault code found.
-------------------------------------------------------------------------------
Address 17: Instruments Labels: 1J0-920-xx5-17.lbl
Part No: 1J0 920 906 L
Component: KOMBI+WEGFAHRSP VDO V58
Coding: 07232
Shop #: WSC 58350
VCID: 3163EA72FB7239B6C1-5102
3VWSP69M42M011724 VWZ7Z0A3842382
No fault code found.
-------------------------------------------------------------------------------
Address 19: CAN Gateway Labels: 6N0-909-901-19.lbl
Part No: 6N0 909 901
Component: Gateway K<->CAN 0001
Coding: 00006
Shop #: WSC 00066
VCID: 70E52F7630F870BE8E-5102
No fault code found.
-------------------------------------------------------------------------------
VCDS
Self-Diagnosis Log
Saturday,23,July,2016,14:49:52:23395
Page 3
VIN: 3VWSP69M42M011724 License Plate: ASDFGFGHHJ
Address 46: Central Conv. Labels: 1C0-959-799.lbl
Part No: 1C0 959 799 C
Component: 1H Komfortgerát HLO 0003
Coding: 00258
Shop #: WSC 00066
VCID: 3777D46A1516E7868F-4B00
Subsystem 1 - Part No: 1C1959801A
Component: 1H Tõrsteuer.FS KLO 0002
Subsystem 2 - Part No: 1C1959802A
Component: 1H Tõrsteuer.BF KLO 0002
Subsystem 3 - Part No: 1C0959811A
Component: 1H Tõrsteuer.HL KLO 0002
Subsystem 4 - Part No: 1C0959812A
Component: 1H Tõrsteuer.HR KLO 0002
No fault code found.
-------------------------------------------------------------------------------
Address 56: Radio Labels: 1J0-035-18x-56.lbl
Part No: 1JM 035 157 A
Component: Radio DE2 0005
Coding: 02043
Shop #: WSC 00226
VCID: 3E79C14E3A2CD6CE4C-51B2
1 Fault Found:
00856 - Radio Antenna
36-00 - Open Circuit
End-------------------------(Elapsed Time: 05:07)--------------------------

Sounds like you need a new alternator, not sure what's near you but I have an auto electrician not to far away with a machine they can stick the alternator on to test, rules out everything else.

Thanks for the input, it looks like I will be removing the alternator.

Update: Both wires to the connector on the back of the alternator have ~12VDC. That appears to rule out continuity issues IMO.

Did you change the regulator ?
That 12V is battery voltage supplied to start the charging

Changed the alternator and resolved the problem. Advanced auto tried to test it and it would not test. Also, I could not find a regulator locally, and needed the Jetta on the road. Now running at 13.99-14.00 steady.