We have a Cirrus SR20 in our group. A months ago, the Alt-2 warning light started to come up intermittently in flight. Then from a weeks ago or so the ALT-2 light stays on irrespectable of the engine RPM.
When the ALT selector button is switched to ALT-2, there is no indication of charge on the AMP indicator infact the needle stays on zero.
Any suggestions please?
Well, it sounds to me like a pretty straightforward case of Alt 2 failure, unless I’m missing something. It failed intermittently I guess, but now sounds like it’s dead.
I actually don’t remember whether the SR20 has the same shear coupling issue that the SR22 #2 alternators have - a plastic coupling which connects the engine accessory drive to the alternator can shear, which is one way alt 2 can die (again this may be SR22 only). You could also check the field wire for security - on SR20 ALT1s this has been a problem historically but not so much on the Alt2, since Alt2 is behind the engine and protected to a certain degree from the ram air in flight.
Otherwise, you may just have to pull alt 2 and send it for IRAN (inspection & repair as necessary).
when I had a 20 i had the same problem. after much time and $$ it wound up being the MCU.
Sad to inform you, my SR-20 had a similar eventual diagnosis.
As did mine. Twice. Once right after delivery (end of 2006) and again this past November. Good times.
I’ve just starting seeing warning indication on the MFD and when checking Eng page I notice a amp discharge of -7. This happen two different times with cruise power set.
Any suggestions?
Thanks everyone specially “Steve Lin”.
The aircraft was taken to a maintenance organisation. The initial suggestion was that the “coupling” between the alternator and the small gearbox is sheared. So had to order the parts to Cirrus US. I will let everyone know if this is the only cause of problem.
Thanks again