Weird voltage issues (84 4kq)

[John B]

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.  

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

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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