"Morgans" wrote in message
...

"Morgans" wrote

It could be that it is not putting out enough voltage/amps while it is
under load.

To further expound on that point, you need to know what the power draw is
demanded by the unit. Take a thin piece of cardboard, and put a wire on
one side to contact the positive battery contact, and run it to an
amp/ohm/volt meter, then back to the contact of the GPS unit, to be able
to read the amps (or milliamps) actually drawn from the batteries.

Of course, the output of the ships power adapter must be equal to or
greater than the draw of the GPS. I really think you will find your
problem, there.
--
Jim in NC

Interestingly, someone sent me a private e-mail indicating that he had the
same problem with his Lowrance Airmap 100. He resolved the problem by
trading up to a newer unit. ;-)

Reading through the Airmap's manual, it is supposed to switch to the ship's
power if the voltage from the ship exceeds the voltage of the 4 AA's, which
is roughly 6 or 6.5V. There shouldn't be a problem with the power from the
airplane. Its voltage is ~14, and the circuit is fused for 10A and wired
for 15-20A. I've checked the voltage it on several occasions.

My guess is that there is a problem with the internal switch on the Airmap,
and that I can't solve it on my end.

I guess I'll just have to keep feeding the thing AA's.

KB