Re: Alternator Voltage & Amperage (load) Testing

Steve wrote:
> 
> Daniel Stern Lighting wrote:
> 
> > On Tue, 2 Dec 2003, LanceM wrote:
> >
> >
> >>Last night noticed that my 91 Saab 900 at idle, with nothing on except
> >>for hazard lights, the fuel pump pitch noise was going up and down in
> >>perfect synch w/hazard lights on/off.
> >
> >
> > Bad grounds.
> >
> > DS
> >
> 
> Or bad primary power feed from somewhere upstream of the
> distribution/fuse center but downstream of the
> alternator/battery/regulator. Either one would cause the same problems
> despite a perfectly good alternator and a perfectly solid and stable
> battery voltage.

I agree with Steve, but restating, you  say you are seeing a voltage drop at
the fuel pump caused by the flashers.  I'd say this means you have a connection
or component (small wires) somewhere in the wiring that has a relatively high
resistance and it is in a common circuit with the flashers and fuel pump (when
both are on, the current increases as does the voltage drop across this other
resistance).  If you cannot measure a voltage drop at the battery with the
flashers flashing, then I wouldn't suspect the alternator.  I wouldn't worry
about it too much, but check all connections that are common to the fuel pump
and flashers...