Re: "Pulsing" voltage

[cordeiro@adi.com (Alan Cordeiro)]

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Having just replaced the ground strap from the alternator to the engine
on my 82 4000 diesel, I noticed that the voltage meter in the car seems
to pulsate between 13 and 14 volts, with the pulsing increasing in speed
as the RPMs increase.  The meter reads a steady 14 volts at idle.  I have
charged the battery to full, replaced the ground and the hot lead to the
battery, but I suspect the voltage regulator is the problem.

Does anyone know of a cure?

Thanks in advance!

-- 
Joe
bossoj@rpi.edu


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1. The problem appeared after you replaced the ground strap.
  
2. The alternator performance seems to have a mechanical
   vibration type effect superimposed on it.

Possible cause:

    You have a bad ground strap, and the ground through
    the alternator mounting bolts and brackets is kind
    of intermittant. 

==> Add another ground from the alternator DIRECTLY to the
CHASSIS, see if that makes any difference. Make sure you 
really clean the metal surfaces where the ground makes contact,
since 90 to 120 amps may be flowing through this connection.

If this makes a difference, clean the places where the
first ground strap bolts onto metal surfaces. You may want 
to also clean up the places where the engine grounds to the
chassis.

Then again, it could be the voltage regulator, or the
positive voltage contact ( inside the alternator ) to
the regulator is intermittant. Is this the original, or
has it been replaced recently.  

Alan Cordeiro