I repaired one of these last month ( friend who lives on a barge ! )

Inside at the front is a printed circuit board with a large relay underneath
it, yes ? towards one corner ( same side as the start/boost switch towards
rear of pcb ) there is a small 10uF 25v electrolytic capacitor which will be
dried up and open circuit. This causes the relay to quickly pulse on/off
instead of coming on until the battery reaches a high enough voltage. Also
the green 12v bulb on the front panel which is lit all the time a battery is
connected had gone ( spare xmas tree bulb fitted fine ).

--
Pete Cross


wb wrote:
On Tue, 15 Feb 2005 01:40:12 -0000, "Paul King"
wrote:

wb wrote:
My battery charger seems to be faulty - cutting out as soon as it
is
plugged in, with a flash coming regularly every couple of seconds
(from a fuse-like bulb located on top of the coil (cover off)).
It's a good enough charger when it's working, with boost/fast
start as
well as trickle; it also has an automatic cut-out to prevent
over-charging. With the cover off, there does not seem to be any
obvious short.
Any ideas?

Long distance diagnosis of this sort is impossible without greater
information ... What make/model is the charger? When was the last
time you
used it and "knew" it to work? Why do you have the top off and what
leads
you to think its faulty? Is not the battery screwed perhaps, leading
to the
charger shutting down due to overcurrent?


It's a "GUNSON's Rapid Start Heavy Duty Starting Charger suitable
for
all 12v Lead/Acid batteries
Start: 47A RMS 30A DC @ 9v (10-15 secs)
Boost: 26A RMS 17A DC @ 12v (10 minutes)
Fast: 15A RMS 10A DC @ 12v (continuous)

Recommended minimum battery capacity: 30Ah.
Full overload protection,
Reverse polarity protection.
Thermal cut-out protection."

I last used it at Christmas to quick start my car battery; it worked
fine. My son put it on an old (12v) battery he had been using for an
electric fence for his chickens (does not need full 12 volts). He
noted it flashing a making a pulsing clicking sound. I then tried it
on a working forklift battery with the same result.
I took the top off to check for any obvious shorting or dampness. I
have never noticed it flashing prior to this. Needless to say, I
can't find the instructions anywhere.

post the circuit diagram for us, get ready with the multimeter, and
we'll see if we can take you through it.

NT