Lane A and B generator failure on 2nd flight

[deene]

We had a vexing failure on the 12is that was recently completed by the Tango program. The signature was an intermittent low voltage and battery discharge warning from a possibly failing generator B. In this case, a B generator failure does not cause a lane B fail light indication

After major debug effort with excellent support from Vans and Leading Edge Airfoils, I found an intermittent pin on one of the connectors on a cable from the Rotax fuse box to the HIC module behind the instrument panel. This caused intermittent operation of the B generator regulator.

Since this was a prefabricated cable supplied with the RV12iS kit, you should carefully examine the connectors on the cables to the HIC. In our case one pin would not stay seated which cause the intermittent failure.

We replaced the pin on the wire and carefully installed it in the connector shell and all was well...

[jcboon]

Hi Deene, that is very helpful!!

Was it one of these connectors? On the AV-60009?

[deene]

Yes, also called the ?HIC? or Harness InterConnect module. Check pins by inspection on all four cable connectors.

[jcboon]

I checked all four connectors today. Every pin and wire. They were OK as far as I could see.
It is perhaps of interest that not one, but both lanes have this problem. And not on and off intermittently, but rock solid immediately after starting the engine.

The dongle that I bought worked fine with Rotax' simulator. But I cannot get it to connect with my maintenance port. No signs of life. The maintenance port (also) interfaces with the Harness Interconnect module. Maybe there is something wrong with the module. I discussed that today with Vans support and they will check with their expert(s).

[jcl777]

The wiring in my port was wrong. The two wires had to be reversed. Check with Vans, but that was my issue.

[jcboon]

Hi John, thanks! Vans also suggested to check and try reversing the two wires of the maintenance port.
I tried this morning. The wires were inserted OK. Then I reversed them. But it didn't work in either way. Not even a flicker of the steady dongle light. Afterwards I reversed them back to their original postion, like so:

[NinerBikes]

What RPM's are you supposed to run the motor at, after start up? I know at least on a 912 ULS, you need to keep the throttle at 2000 rpm, and for the gearbox, they want you to idle on warm up closer to 2500 rpm. At those RPMS, your current in amps will stay positive.

Wondering if it's different or the same for the 912 iS model, too?

[jcboon]

After starting you have to go to 2,500 for a few seconds and then slow down to 2,000. That is for the K1/K2 relay to switch power from the generator B to the main bus and generator A to the engine computers. I deleted my previous message with the log file and will post a better example of a SV log.

[jcboon]

Here is a typical example of what happens in the log files (from Dynon) 50 sec after starting the engine. The amps change from + into -. Subsequently errors appear and information disappears while the engine is still running. I am not smart enough to interpret these data, but perhaps one of you can.

[NinerBikes]

files or Jpg's not visible. If you are getting positive charge and voltage over 13.7V after starting, it's not your alternator or generator, it's something else.