Dave:
>for 24hours as suggested. is it ok to just leave on one battery ( charge
will
> flow over into second I assume since they are connected in series). If
they
You can charge at 12V if you go across both batteries since they are in
series. You can charge one at a time at 6V since they are NOT in parallel.
If you are charging one battery at 6V the current will not flow into the
other battery. It must be charged separately.
> what did you think about my comment on the starter engaging/disengaging
while
> cranking? low battery could cause?
I think low battery could cause this. But if each battery is at 7V after
charging, for a 14V string total, the battery is not probably low. I think
the problem maty be the battery to ground wire or connection. Or the battery
cable to the starter connection. Or the ground strap from engine to chassis
connection.
I had a bad connection on the engine ground strap that caused the starter to
run VERY slowly. So slow that it would not always start the engine. To
isolate the cause I did this simple test. I used a good heavy gauge (#4 wire
home-made) jumper cable. I connected the cable across the factory made
connections. First from battery negative to a clean place on the chassis.
Then started to the car. Starter still slow.
Second from batt negative to engine. Then started the car, but this time it
started OK. AHAH I says to myself. I have found that there is a poor
connection from engine to ground (since ground to batt is ok).
This method works because you are paralleling the poor connection (or bad
wire), with a good wire and connection. The resistance of the poor circuit
goes from ohms to milliohms and Viola, you have the location of the problem.
You still need to discern whether the wire or the connection is bad, but 9
times in 10 it will be the connection.
But I digress. First make sure those batts can hold a charge. 7V each or 14V
across the string after the trickle charger is removed (for a couple hours)
is very good. What about under load? Put on the lights. What is bat voltage
now?
Kind regards...
Tim
>
> thanks again Tim.
>
> Dave Ciaccio
> Omaha, NE
> '74B
> '76B
>
> Tim Economu wrote:
>
> > The alternator should put out over 14.0V when the engine is over 2000
RPM.
> > If the voltage bumped to 8.5V then either a number of battery cells are
> > shorted (very unlikely to have more than one), or the alternator is bad.
Did
> > you measure from chassis ground to the plus on the second battery? If so
> > then measuring each battery would produce about 3.5-4V. Are your battery
> > connections clean? Is the connection to the chassis renewed?. I would
remove
> > all connections and clean and apply Vaseline to prevent oxidation.
> >
> > If each battery is less than 4Vafter charging, my guess is that the
> > batteries are toast. Try charging again after cleaning connections.
Charge
> > for 24 hours then retest. IF still under 12.8V total, the batteries are
in
> > for replacement. Personally, I will stick with two batteries. More lead
=
> > more starting power, even if the cold cranking amps are similar. The
cost
> > just doesn't justify the swap in my opinion.
> >
> > If batteries after cleaning and charging are > 12.8V, then start the car
and
> > rev to over 2000 RPM. The voltage should rise to between 14.0 and
14.8VDC.
> > Still OK? Then alternator is probably working. (Only way to tell for
certain
> > is to put a dead battery on the alternator with a ammeter in-circuit and
see
> > if it will charge about 60 amps --my '69 MGB spec-- ). I would take the
> > batts to a repair shop and have them put their "load tester" on the
batts.
> > This will tell you whether you need to replace them or not.
> >
> > Good luck...
> > Tim
> > '69 BGT mona
> > ----- Original Message -----
> > From: "Dave" <hearts@radiks.net>
> > To: "Larry Dickstein" <bugide@tfs.net>
> > Cc: <economu@whidbey.com>; <hjillson@argohouston.com>;
> > <paul.hunt1@virgin.net>
> > Sent: Sunday, April 09, 2000 7:03 PM
> > Subject: Re: radio sings the blues-test done
> >
> > > Hi Larry!
> > >
> > > Hope you had a great weekend. Nice weather here in Omaha and took out
the
> > '74B
> > > for about 30-40 miles with the top down. Drove great, ran great. No
sign
> > of
> > > the radio noise.
> > >
> > > regarding the test, it looks like the end for the twin 6 volt
batteries.
> > they
> > > tested at 7 volts. I put a trickle charge on them for about 6-7
hours.
> > no
> > > luck. still tested at 7 volts. I then cranked up the engine (very
slowly)
> > and
> > > because its a good starter, it fired up. the voltage bumped to about
8.5
> > volts
> > > which tells me the alternator is ok. drove for the 30-40 miles in
town
> > (not
> > > shutting it off). got home and retested. same results with engine
off - 7
> > > volts.
> > >
> > > not sure how this relates to the radio noise but it does tell me why
when
> > the
> > > headlights have seemed dim and why, when cranking, the starter seems
to
> > engage
> > > then slightly diengage while cranking...not full voltage to keep the
> > selenoid
> > > engaged ( I guess).
> > >
> > > anyway, I did check the antenna to the radio as Paul Hunt suggested.
> > seemed
> > > tight. did not check the small coil wire yet. but again, it did not
do
> > it
> > > today. I did replace the hazard light switch and fan switch but
don't
> > think
> > > thats any relationship.
> > >
> > > so now I think I'll replace the batteries. thinking of eliminating
the
> > 2-6
> > > volts and going with 1-12volt as I have read others doing. would you
> > advise
> > > this? if so, where can I find instructions for doing so? and, of
course,
> > what
> > > size would that 12 volt be?
> > >
> > > I have copied Paul Hunt, Harlan Jillson and Tim Economu on this since
they
> > > originally responded to my first message as well. any input from
any/all
> > you
> > > guys would be appreciated when you have time.
> > >
> > > have a good week!
> > >
> > > Dave Ciaccio
> > > '74B
> > > '76B
> > >
> > > Larry Dickstein wrote:
> > >
> > > > Dave wrote:
> > > >
> > > > > Was driving the '74B sunday when all of a sudden a fairly loud
whine
> > > > > came out of the radio. At the same time the "fasten seat belt"
light
> > > > > started to glow. sounded like it was trying to buzz too. I
notice
> > the
> > > > > noises got louder with higher engine revs. sounds to me like some
kind
> > > > > of voltage transfer. before I pull the radio, I thought I would
check
> > > > > out the advise of the list. I have only owned this one for 4
months
> > but
> > > > > never heard this noise. All other electrics seem fine. Any
advise is
> > > > > appreciated!
> > > > >
> > > > > Dave Ciaccio
> > > > > '74B
> > > > > '76B
> > > >
> > > > Dave-
> > > > I think the radio whine was a symptom but not the cause. My
guess
> > would
> > > > be a malfunction in the alternator/voltage regulator. It wouldn't
be
> > > > adviseable to run it in this condition long but a fast check of
voltage
> > w/
> > > > the car running should tell you the story. If the battery is up the
> > voltage
> > > > w/ the car not running should be 12+. The high normal voltage w/
the
> > car
> > > > running should not be over a high 13 or low 14. Your observation
that
> > the
> > > > noise increased w/ rpm is the key and a good observation on your
part.
> > > >
> > > > --
> > > > Larry Dickstein
> > > > Lone Jack, MO
> > > >
> > > > Pop. 420
> > >
>
|