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bbs428
11-21-2022, 08:50 AM
I think I'm right on the basic wiring of this used 912ul engine, but I have zero experience. I have read the install manual and that helped. I have tried to bring up wiring diagrams from the past (1993) with no luck

Here's what I have:

1. Of the two wire bundles coming from the port side of the internal generator, one has two feeding shielded brown wires, approx. 26" long both with sockets for the rectifier.
From the install manual - Feeding wires from the generator to rectifier-regulator on left side of ignition housing 2 flexible cables, 1.5 mm2 yellow (in shielding metal braid) length approx. 660 mm (26 in.) starting from ignition housing• with on each plug socket 6.3 x 0.8 to DIN 46247.
I'm assuming these are the regulator feed wires?

2. On the other is a smaller bundle of two wires, alongside the regulator feed wires, both white - one with red stripe, one with green stripe.
Manual states - 2 flexible cables 0.5 mm², white/yellow and blue/yellow in insulation wrap.
I'm assuming that these are the tach wires?

3. I have the older 4 plug electronic box connectors. There is an empty socket next to each connector. I'm assuming these are for ignition circuit A and B?

Comments?

31124
31125

Jerrytex
11-22-2022, 07:53 AM
The 2 small wires with the stripes are definitely tach wires. I know when I hooked up my EFIS, I had to ground one as per the manufacturer and the other was the signal to the EFIS. On my 1993 912UL, and every other 912 I have seen, the charging wires that go to the regulator are yellow. But if yours are going to the stator, than they are definitely the charging wires that go to the regulator. Wonder if the ends of the wires are discolored?

The bullet connectors on the ignition are for the ignition switches.

Sounds like you are getting close to a first engine start...... Very exciting!

*Also, double check the crimps on the two female spades on the charging wires. I had a bad crimp on one of mine and on one flight, it got super hot and melted part of the wire insulation causing the cockpit to fill up with smoke and me to ruin a perfectly good pair of underwear.

bbs428
11-22-2022, 12:48 PM
I cut the heat shrink off the end on the two feeding/charging wires and they are a nicer, deeper brown. Lol, guess it will stay a mystery for now. The gauge of wire and the style of connecter or lack of, give it away as to the feed/tach wires.

Thanks for the heads up on the crimps. I am going to change the connectors out for new, tinned marine connectors.

Logical those bullet connectors are the for the ignition.

Hal Stockman said it ran very well after all the mods and big bore conversion, also that it was in very good condition for being that old.
I should be that lucky.

I appreciate you posting Jerry! Thanks!

AvDES LLC
11-22-2022, 08:18 PM
I cut the heat shrink off the end on the two feeding/charging wires and they are a nicer, deeper brown. Lol, guess it will stay a mystery for now. The gauge of wire and the style of connecter or lack of, give it away as to the feed/tach wires.

Thanks for the heads up on the crimps. I am going to change the connectors out for new, tinned marine connectors.

Logical those bullet connectors are the for the ignition.

Hal Stockman said it ran very well after all the mods and big bore conversion, also that it was in very good condition for being that old.
I should be that lucky.

I appreciate you posting Jerry! Thanks!

I had that same issue with the wiring on the stator I received as a replacement to the one I managed to destroy. Ended up having to solder a whole new length of wire from the stator up and put new bullets on it. Really wasnt that difficult so consider doing it next time the plane is down for a bit - its nice piece of mind knowing your charging system isnt relying on blackened wires and gummy insulator.