B737 APU 3-speed Switch

[itflewin,itllflyout]

Hello all,
Can anyone please provide a run-down on a APU 3-speed Switch please? I once had to 'technically percuss' one (adjacent to DFDR on a Classic), and I remember it fixing 3 individual defects we had at the time, a few of which I remember were indication problems in the Fdeck. It was some years ago so I very much appreciate your assistance. Many thanks and regards
IFI

[itflewin,itllflyout]

ASFKAP,
Very kind of you, have noted same with thanks. Now youve jogged my memory Im also wondering if the 'APU Gen off Bus' annunciator has part of its signal origins there also. I seem to remember an APU speed of 98% ? criteria for this light on the Elect Sytems panel on P5.

Anyway, I remain grateful for you taking the time to reply. Yours in fading memories. IFI

[itflewin,itllflyout]

Thank you mate, all the best for the New Year
IFI