Hi
OK so after my mix up with my engine pull and the earth/live mix up I replaced the 200amp fuse and the car is running BUT now I have a battery light on on the dash... I have triple checked and cleaned all 4 earths (earth by the battery, earth by the alternator, earth on the firewall and the earth at the back of the tappet cover on bank one), I have also cleaned and checked all of the terminals by the 200 and 150 amp fuses..
with my volt meter and the motor ruuning I am getting 14.2V at the alternator itself, this was tested with earth to the motor and the earth to the chassis leg (the normal earth), at the 200/150amp fuses I am getting 13.9V across all the terminals and at the battery I am getting 13.2V (I think.... need to double check again.
I took the alternator off and send it to local alternator/starter guys who put it on there bench and tested the alternator and it was fine even under 90amp load they also checked the brushes and couldnt find anything wrong...
Searching everyone is pointing to the regulator surely the alternator repair guys would have picked up an issue if it was that?
Any help/pointers please guys.... just want to get the car back on the road now...
battery light/alternator issue
Re: battery light/alternator issue
I wonder if you damaged something when you reversed the polarity.
What does the dash voltage gauge read? What does the Vagcom say the voltage is?
What does the dash voltage gauge read? What does the Vagcom say the voltage is?
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
Re: battery light/alternator issue
The car didnt run but yes maybe I did, dash voltage is showing just under 14V I will need to check with VCDS again but it was reading like 13 something..
Re: battery light/alternator issue
Did you plug in the 1 pin connector (might be 2 pin, can't remember) to the alternator as well as the power cable?
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
Re: battery light/alternator issue
The wiring from that connector go to the instrument cluster (via a couple of terminals). I am pretty sure that it is what the cluster is using to see if the alternator is working. Maybe check the connector is making a good contact.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
Re: battery light/alternator issue
This is what has me confused, it is a single wire connector and that connector is in the same harness that goes to the 200/150amp fuses and the only other plug that comes off that harness is the one in the picture below which sits by the 02 sensor plugs... I must be missing something small here.
Re: battery light/alternator issue
The connector I'm talking about connects directly to the alternator.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
Re: battery light/alternator issue
I suspect you have blown the ind circuit within the voltage regulator, should be a cheap fix. The alternator self excites so you get good voltage and current readings when testing.
Avus Avant, RNS-E mk2 with sds and Bluetooth, Milltek, Hotchkis, Bilstein, Forge, ITG, A.C.E, Wagner, FBMFSW, MTM.
Re: battery light/alternator issue
thanks Bilko... really really dont want to have to pull the alternator AGAIN. One last thing with the "excite" plug disconnected the voltage on the dash drops down to probably about 8 volts with the car running and with my volt meter I am seeing 1.48V at that plug so in the plug itself on the harness not the alternator side.. I found another post somewhere where the voltage measured at that plug was 9.8V where as mine is only at 1.48V
Just really dont feel like taking my front end off again to pull the alternator.
Just really dont feel like taking my front end off again to pull the alternator.
Last edited by airtite on Tue Oct 26, 2021 6:14 am, edited 1 time in total.
Re: battery light/alternator issue
still confused where that "excite" wire goes or at least exits out of the alternator/starter harness anyone?
Re: battery light/alternator issue
You don't ned to pull the front end to remove the alternator. Takes about 2 hours to change but gets messy with the oil lines you need to remove.
Avus Avant, RNS-E mk2 with sds and Bluetooth, Milltek, Hotchkis, Bilstein, Forge, ITG, A.C.E, Wagner, FBMFSW, MTM.
Re: battery light/alternator issue
I can't access my Elsawin since I upgraded to Windows 10 
Perhaps Shop or someone else can check the wiring diagram. I'm pretty sure the ind terminal is earth until engine starts / alternator charges then it has charge voltage which puts the battery light out as the earth is gone. If my theory is correct with the ind wire disconnected from the alternator and ignition on you should get battery voltage at the ind wire and the battery light should be off.
Perhaps Shop or someone else can check the wiring diagram. I'm pretty sure the ind terminal is earth until engine starts / alternator charges then it has charge voltage which puts the battery light out as the earth is gone. If my theory is correct with the ind wire disconnected from the alternator and ignition on you should get battery voltage at the ind wire and the battery light should be off.Avus Avant, RNS-E mk2 with sds and Bluetooth, Milltek, Hotchkis, Bilstein, Forge, ITG, A.C.E, Wagner, FBMFSW, MTM.
Who is online
Users browsing this forum: steve2003rs6 and 116 guests