The + 12V power lead to my B40 fell out the back of the unit at some
point and made contact with ground during its subsequent tour of the
area behind the panel. The (?)-amp, 5x20mm fuse in the instrument
panel was blown, as well as the 0.25 amp fuse of the same size on the
back of the B40.

I know the purpose of the panel fuse is to protect the wires, and the
B40 fuse is to protect the instrument (I think). Can I safely use a
0.25 amp fuse in the instrument panel and maybe a 0.5 amp fuse in the
B40? (The B40 is the only item on that fuse; the radio, LX and 302
have their own.)

Btw I've checked the B40 manual and can't find any mention of fuses.
Is 0.25 amp the correct fuse?

Thanks

~ted/2NO

On Dec 8, 10:20*am, Tuno > wrote:
> The + 12V power lead to my B40 fell out the back of the unit at some
> point and made contact with ground during its subsequent tour of the
> area behind the panel. The (?)-amp, 5x20mm fuse in the instrument
> panel was blown, as well as the 0.25 amp fuse of the same size on the
> back of the B40.
>
> I know the purpose of the panel fuse is to protect the wires, and the
> B40 fuse is to protect the instrument (I think). Can I safely use a
> 0.25 amp fuse in the instrument panel and maybe a 0.5 amp fuse in the
> B40? (The B40 is the only item on that fuse; the radio, LX and 302
> have their own.)
>
> Btw I've checked the B40 manual and can't find any mention of fuses.
> Is 0.25 amp the correct fuse?
>
> Thanks
>
> ~ted/2NO

I don't see how the B40 fuse could have been blown if the power wire
was disconnected. You may have another problem. If you don''t find
an answer on the B40 fuse size call me at home (leave msg) and I'll
check mine.

Andy

On Dec 8, 9:20*am, Tuno > wrote:
> The + 12V power lead to my B40 fell out the back of the unit at some
> point and made contact with ground during its subsequent tour of the
> area behind the panel. The (?)-amp, 5x20mm fuse in the instrument
> panel was blown, as well as the 0.25 amp fuse of the same size on the
> back of the B40.
>
> I know the purpose of the panel fuse is to protect the wires, and the
> B40 fuse is to protect the instrument (I think). Can I safely use a
> 0.25 amp fuse in the instrument panel and maybe a 0.5 amp fuse in the
> B40? (The B40 is the only item on that fuse; the radio, LX and 302
> have their own.)
>
> Btw I've checked the B40 manual and can't find any mention of fuses.
> Is 0.25 amp the correct fuse?
>
> Thanks
>
> ~ted/2NO

Ted,

The fuse is 2 amp. Sometimes if +12v power touches the case of the
B40 a fuse link on the circuit board on the back of the unit is
blown. You can check this by following the circuit and using a
voltmeter.

Richard
www.craggyaero.com

I've had trouble decoding the text on these small fuses, but the one I
took out of the panel is labeled "T500L250V", which I now guess to
mean 0.5 amps, 250 volts, slow blow.