August 13, 2006

For some reason, I’ve never had my fuel pump warning light come on while we’ve been running the plane, so I decided I needed to troubleshoot the item today while epoxy was setting up on the wingtips.

I double checked my wiring, and sure enough there was the problem. I wired it so that all the wires leading to the light were gorunds! Well, as we all know, bulbs need some positive electricity flow to work, so I set about fixing the issue. Looks like I’d mistakenly thought the FADEC harness was supplying power when in fact it was pulling low. Duh! I fixed that little error and set about running the engine to confirm the fuel pump light worked as expected. Unfortunately, this took a while as I had also taken all the ignition leads of the plane last night to measure the lengths I needed to order to make the harness work neatly. I put all the leads back on and pushed the plane out for an engine start.

The fuel lamp came on as expected, at idle because the FADEC was turning on the boost pump as the engine driven pump wasn’t supplying quite enough pressure. As I brought the RPM up the boost pump (and the lamp) turned off as the engine pump was now able to supply the pressure the FADEC was demanding. Perfect!

It seems now that I have all the FADEC stuff wrapped up except the ignition harness. I’ll order those tomorrow, so we should be good to get that out of the way in the next week or two.