Voltage Regulator Failures

[peter anson]

At some point a few years ago Jabiru changed from a parallel winding to series winding of the stators. The result is a bit higher voltage per RPM than earlier models. You may have the older version.

David A.

The manual specifies 40VAC at 3000 rpm for the series wound alternator compared with 30VAC for the parallel windings but I couldn't find any information on when they changed to the different windings. Well. OK, I didn't look. 18 volts still sounds way too low for no load at 2500rpm. If you still doubt you need to do a short full throttle run; safe enough if you tie the tail down. 30 or 40 volts might sound very high but the voltage drops considerably under load.

Peter

[gyroron]

After carefully inspecting my wires coming out of the regulator and where they go to, then finally looking at the wiring diagrams in the jabiru engine manual, I am 99 percent sure I have the wire that is supposed to go to the ground on the battery, installed on the positive post of the battery. I will make 100 percent sure next time I am at the airport and report back

[gyroron]

Yep, was at the airport yesterday. Sure enough, the wire coming out of the regulator that should be going to " Earth " was routed to the positive post on the battery.

I replaced the battery a few weeks ago and I am pretty sure I reconnected all the wires back to where they were when I took them lose from the old battery. So either myself, or the previous owner put that wire on the wrong post.

It would be easy to do... All 3 wires coming out of the airplane side of the regulator plug, they are all yellow wires. One going to fuse box, one goes to + on battery and one should go to ground.

Put the ground one from the positive to negative post, rolled plane out and tied it down and ran it up. Was seeing up to a little over 14 volts at 2500 and higher rpms. And tach was smooth and steady unlike before, and seemed to be no noise in the radio either. Fingers crossed this is now fixed.