Weird voltage issues (84 4kq)

[Huw Powell]

On 3/1/2011 11:11 PM, John B wrote:
>
> Hey everyone,
>
> It's a grounding issue. Today I added a 10awg ground from the back of the alternator housing to the block and all issues have been solved (thanks for the tip John!). I plan on replacing the existing battery ground strap with a cable, and re-grounding off some of the sub systems. The battery ground itself looks pretty shabby at best, and I noticed where it connects to the transmission bolt it has a few frayed wires from the rope so everything is getting a once over. Im assuming with the lower volts I was getting from the last alternator the bad ground wasn't as noticeable.

Clean the alternator mounting brackets and you'll have a good ground 
with no extra cable. But if it works, it works...

> Question, is the transmission bolt the best spot to ground the battery to? I have a 6' cable to play with...

Yes, but don't forget to ground the chassis/body as well, either to the 
battery or to the engine/tranny.

> Johnny
>
>> Date: Tue, 1 Mar 2011 18:29:47 -0500
>> Subject: Re: Weird voltage issues (84 4kq)
>> From: speedracer.mark at gmail.com
>> To: audi at humanspeakers.com
>> CC: john at westcoastgarage.net; auditony at gmail.com; pre95 at live.com; quattro at audifans.com
>>
>> Did anyone else notice the non-utilized "B" fitting?  "B" on an alternator
>> or "B+" is for a direct battery connection to +12V.  Any "B-" connections
>> for battery ground would be clearly identified with the "-" or
>> "minus" symbol or lettering.  B+ is sometimes only stamped "B" from my
>> memory.
>>
>> It sounds like the incorrect alternator or incorrect installation.  Anyway,
>> a proper voltage and ammeter (load) testing would be the next step if it is
>> the correct P/N, to test both the part itself as well as the installtion.
>>
>> I've had brand new alternators not work correctly and one high-quality reman
>> failed catastrophically (locked up) after a few thousand miles on
>> my Escalade, taking out the new serpentine belt in the process.
>>
>> Mark Rosenkrantz
>>
>> 2011/3/1 Huw Powell<audi at humanspeakers.com>
>>
>>> That's where I was going - combination of a soft engine mount (lets
>>> engine move substantially under load) and a bad connection or rubbing
>>> wire that is only a problem when the engine moves.
>>>
>>> The alt ground is via its case to the engine block.
>>>
>>> The "exciter" is the small wire you mentioned.
>>>
>>> Make sure the battery ground wire is cleanly and securely connected to
>>> the battery tray and the engine block/transmission bolt.
>>>
>>> Have you run a voltmeter in the cabin yet, or are the headlights your
>>> stand-in?  Could just be a problem in the lighting circuit(s)...
>>>
>>> On 3/1/2011 1:00 PM, Andrée-Anne Bourgeois wrote:
>>>> Also, check that passenger side engine mount. If dead, then engine will
>>> rock
>>>> a lot under acceleration.
>>>>
>>>> Louis-Alain
>>>>
>>>> -----Message d'origine-----
>>>>
>>>>
>>>> John, in addition to what has been mentioned:
>>>>
>>>> It almost sounds like a wire is rubbing somewhere when you floor it. I'd
>>> be
>>>> checking the wiring around the engine. Try moving the wiring around while
>>>> the car is at idle and see if you can duplicate the problem. The full
>>>> throttle thing is what has me leaning toward this conclusion. Oh, and if
>>> it
>>>> started occuring when the alt was changed, look at the wires connecting
>>> to
>>>> the alt, and in that immediate area.
>>>>
>>>> Tony
>>>>
>>>>
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>>>>
>>>
>>> --
>>> Huw Powell
>>>
>>> http://www.humanspeakers.com/audi
>>>
>>> http://www.humanthoughts.org/
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-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/