Let's start this baby..... or not

[LettersFromFlyoverCountry]

As I work my way through PAP on the 12iS, some weirdness happening on PAP G4-2, enabling the starter circuit.



Red warning light comes on on spar pin removal. Cool.

Starter circuit is apparently disabled while red warning light is on. Also cool.

Pushing red light does not override starter circuit. Not cool. Not cool at all.

Putting the wing pin back in with red light off also does not result in an engaged -- or even a "let's just move in together" -- result.

Obviously a problem with the starter circuit.

Curiously, I get a red X over the oil pressure indicator on the G3X with Lane B on. That strikes me as new. It has me wondering if these are two different issues or connected in some way?

Seems to me, the next logical step is to complete SL-0072 (I already had the part on order) and retry.

Status: Cowling off. Air probe at filter disconnected. Spark plugs removed.

 

[Bob Y]

A friend had the same issue of the starter solenoid not picking up. Turned out to be a bad ignition module. This occurred during his build process so brand new. I installed mine in his aircraft to confirm it. Maybe you have a local friendly 12 owner that would be willing to do the same?

Can’t help you with the oil-pressure issue, as Lane B does power oil pressure and temperature indicators.

 

[LettersFromFlyoverCountry]

A friend had the same issue of the starter solenoid not picking up. Turned out to be a bad ignition module. This occurred during his build process so brand new. I installed mine in his aircraft to confirm it. Maybe you have a local friendly 12 owner that would be willing to do the same?

Can’t help you with the oil-pressure issue, as Lane B does power oil pressure and temperature indicators.

I think Sl72 will be the problem

The 12 owner I flew with today (SLSA) says he often gets the red X until engine start

 

[rcarsey]

I recently (accidentally and unbeknownst to me until the cowl was completely back on) unseated the oil pressure sensor's connector while replacing coolant hoses. When your Lane A & B switches are on, and you have all engine sensors showing EXCEPT for the oil pressure.. idk, I'd just check the connector -- its right by the starter on the copilot side of the engine. The wire goes into the Rotax wiring harness and back to the ECU.. so theres little wiring issues that it could possibly be...

 

[LettersFromFlyoverCountry]

I recently (accidentally and unbeknownst to me until the cowl was completely back on) unseated the oil pressure sensor's connector while replacing coolant hoses. When your Lane A & B switches are on, and you have all engine sensors showing EXCEPT for the oil pressure.. idk, I'd just check the connector -- its right by the starter on the copilot side of the engine. The wire goes into the Rotax wiring harness and back to the ECU.. so theres little wiring issues that it could possibly be...

Everything appears to be in order

 

[jrtens]

Definitely complete SL00072 before buying any more parts.

 

[LettersFromFlyoverCountry]

Judging by this response I got on Rotax-Owner.com, this is going to be a bigger problem than I imagined.

Bob,

I think the lack of responses is do to many of us being unfamiliar with the specific electrical components used in the Vans RV12iS. This is likely an aircraft wiring problem rather than a problem with the Rotax system. Since the Rotax 912iS does not use ignition modules, I assume you are talking about the Vans ignition control module which controls the timing of the application of start power. Also, I believe the Vans HIC modules are simply a wiring interface between the HIC connectors and the aircraft wiring. That said…

I don’t think this is a problem with the Vans ignition control module. This module can interrupt the start power circuit, which would also interrupt power to the starter relay. But that would also shut down the fuel pumps and ECU lanes, which does not appear to be happening.

The starter relay control power originates at fuse 18 in the Rotax fuse box. It then leaves the fusebox as a red wire via pin 5 of the X1 connector. From there is goes through the wiring harness to pin 12 of the HIC-B connector. This does not go through the ECU, it’s a simple fused power circuit so would not be affected by a lane fault. From the HIC connector the power would likely route via the aircraft wiring to the start switch and through any Vans specific safety devices like the wing pin switches, and then back to pin 4 of the HIC-B connector, where it becomes a white wire in the harness and routes to the starter relay. The white wire at the starter relay coil is the 12V+. The black wire at the starter relay coil is the ground (12V -).

The first thing to do is see if power is getting to the starter relay coil when you are attempting to crank the engine. I would disconnect the power wire from the starter relay to the starter for safety, then engage the starter switch and see if there is 12 volts across the black and white wires at the starter relay coil. If not, you need to trace the circuit back and see where the start relay control power is interrupted.

 

[Tony Kirk]

Judging by this response I got on Rotax-Owner.com, this is going to be a bigger problem than I imagined.

Bob,

I think the lack of responses is do to many of us being unfamiliar with the specific electrical components used in the Vans RV12iS. This is likely an aircraft wiring problem rather than a problem with the Rotax system. Since the Rotax 912iS does not use ignition modules, I assume you are talking about the Vans ignition control module which controls the timing of the application of start power. Also, I believe the Vans HIC modules are simply a wiring interface between the HIC connectors and the aircraft wiring. That said…

I don’t think this is a problem with the Vans ignition control module. This module can interrupt the start power circuit, which would also interrupt power to the starter relay. But that would also shut down the fuel pumps and ECU lanes, which does not appear to be happening.

The starter relay control power originates at fuse 18 in the Rotax fuse box. It then leaves the fusebox as a red wire via pin 5 of the X1 connector. From there is goes through the wiring harness to pin 12 of the HIC-B connector. This does not go through the ECU, it’s a simple fused power circuit so would not be affected by a lane fault. From the HIC connector the power would likely route via the aircraft wiring to the start switch and through any Vans specific safety devices like the wing pin switches, and then back to pin 4 of the HIC-B connector, where it becomes a white wire in the harness and routes to the starter relay. The white wire at the starter relay coil is the 12V+. The black wire at the starter relay coil is the ground (12V -).

The first thing to do is see if power is getting to the starter relay coil when you are attempting to crank the engine. I would disconnect the power wire from the starter relay to the starter for safety, then engage the starter switch and see if there is 12 volts across the black and white wires at the starter relay coil. If not, you need to trace the circuit back and see where the start relay control power is interrupted.

So, to debug Van's part of this circuit using the WH-00136-1 schematic you can see the Rotax HIC connector B, pin 12 comes out of the AV-60009-2 HIC Module on the Van's harness 25-pin connector, pin 12 (wire K7009) and goes to the Ignition Module 25-pin connector, pin 12.

Inside the AV-60007 Ignition Module it goes through the key switch then the DPDT Spar Pin relay (or the Spar Pin Override button) and back out of the Ignition Module on pin 20 of the 25-pin connector (wire K7011), where it goes back to the HIC Module 25-pin connector, pin 13, and out of the HIC module on Rotax HIC connector B pin 4, as stated above.

So the test Van's Harness simply ohm out the HIC 25-pin connector, pin 12 to the Ignition Module 25-pin connector, pin 12 (wire K7009) and HIC pin 13 to Ignition pin 20 (wire K7011) for continuity. If it fails this test one of the pins is probably mis-pinned in the connector, and you can use the fancy little pin removal tool to move the pin to the proper location.

You can use the beep tone function of the continuity tester and touch all the pins in the connector to locate the mis-pinned wire. And since all the wires are marked you can open the backshell and identify the wires.

SL-00072 has no impact on the Start circuit, if the fuel pumps run then the Rotax ECU has power, therefore the start circuit would also be powered if fuse 18 INSIDE the Rotax fusebox is okay.

And remember, you can bypass the "Start Button Bypass" feature if it times out by activating the "Backup Battery Switch" next to the fuel pump switches.

 

[Brantel]

@Tony Kirk what on earth is Vans gonna do when you get tired of supporting the RV12 wiring?
Although I am not there yet, thank you! Thank you! Thank you for your support post retirement!

 

[N8DAV8R]

@Tony Kirk what on earth is Vans gonna do when you get tired of supporting the RV12 wiring?
Although I am not there yet, thank you! Thank you! Thank you! for your support post retirement!

Since finishing my airplane I have been thinking about things like adding my GPS175, reading various support threads here & FB, and doing my best to understand wiring diagrams (not intuitive to me but I can usually make sense of things) from Van's and other vendors. One impression I have is that there is a good bit of non-standard or proprietary design and engineering involved in the RV-12. I'm not making a value judgment whether that is good or bad, it just seems to be true. The comments above from the more general Rotax community are just one example.

Getting back to your point, I know that the competition from the SLSA side of the house for parts and attention has been a bone of contention. As frustrating as that may be for builders, it's probably in all of our best interests that the SLSA continues to be grow and have success. We need Van's to have a strong incentive to continue support, especially for the handful of custom electronics components that are integral to the way most of these planes are being built.

 

[LettersFromFlyoverCountry]

So, to debug Van's part of this circuit using the WH-00136-1 schematic you can see the Rotax HIC connector B, pin 12 comes out of the AV-60009-2 HIC Module on the Van's harness 25-pin connector, pin 12 (wire K7009) and goes to the Ignition Module 25-pin connector, pin 12.

Inside the AV-60007 Ignition Module it goes through the key switch then the DPDT Spar Pin relay (or the Spar Pin Override button) and back out of the Ignition Module on pin 20 of the 25-pin connector (wire K7011), where it goes back to the HIC Module 25-pin connector, pin 13, and out of the HIC module on Rotax HIC connector B pin 4, as stated above.

So the test Van's Harness simply ohm out the HIC 25-pin connector, pin 12 to the Ignition Module 25-pin connector, pin 12 (wire K7009) and HIC pin 13 to Ignition pin 20 (wire K7011) for continuity. If it fails this test one of the pins is probably mis-pinned in the connector, and you can use the fancy little pin removal tool to move the pin to the proper location.

You can use the beep tone function of the continuity tester and touch all the pins in the connector to locate the mis-pinned wire. And since all the wires are marked you can open the backshell and identify the wires.

SL-00072 has no impact on the Start circuit, if the fuel pumps run then the Rotax ECU has power, therefore the start circuit would also be powered if fuse 18 INSIDE the Rotax fusebox is okay.

And remember, you can bypass the "Start Button Bypass" feature if it times out by activating the "Backup Battery Switch" next to the fuel pump switches.

Everything above checks out. Not sure if the fuses have lights and I can't find my needle nose pliers to pull it but assuming it's good, I assume I'm looking at the starter solenoid as the next possible culprit .

Also the circuit does not energize via the backup,which is perhaps a further indication my woes are downstream.

 

[MMiller]

Bob,
The Rotax power BUS likely has power since your Garmin display is showing engine data. The wiring diagrams can be confusing to follow. It’s an actually a straight forward series circuit to get power from the BUS to the starter relay coil. Here is a simplified sketch, apologies for the handwriting.

 

[LettersFromFlyoverCountry]

Bob,
The Rotax power BUS likely has power since your Garmin display is showing engine data. The wiring diagrams can be confusing to follow. It’s an actually a straight forward series circuit to get power from the BUS to the starter relay coil. Here is a simplified sketch, apologies for the handwriting.

Unless SteinAir put the wrong label on the wire, I cut and put heatshrink on the correct wire at the relay

(Update to correct: I believe this is Rotax labelling)

 

[Tony Kirk]

Unless SteinAir put the wrong label on the wire, I cut and put heatshrink on the correct wire at the relay

The black wires, one that you clip and one that attach to the solenoid are part of the Rotax Harness.

Have you tested for voltage at the "Conn Starter Rel Sw" terminal (that attaches to the spade terminal of the relay) with the system powered up, lanes both on, both fuel pumps OFF, (and spar pin light extinguished) and the ignition key switch engaged? It should be ~12v with the key engaged and zero with the key off. Be careful that the prop arc is clear.

 

[LettersFromFlyoverCountry]

The black wires, one that you clip and one that attach to the solenoid are part of the Rotax Harness.

Have you tested for voltage at the "Conn Starter Rel Sw" terminal (that attaches to the spade terminal of the relay) with the system powered up, lanes both on, both fuel pumps OFF, (and spar pin light extinguished) and the ignition key switch engaged? It should be ~12v with the key engaged and zero with the key off. Be careful that the prop arc is clear.

That's my next step. Pete Howell is coming over to help tomorrow. He's better with multimeters than I am. We may be calling you with our findings.

 

[LettersFromFlyoverCountry]

Resolution:
It had become obvious to me some time ago that this was a builder error and fortunately, there isn't that much builder involvement in the circuit so before RV Hall of Famer Pete Howell arrived to help me, I went back over each of those areas: Battery to master and master to starter, making sure all the wires were correct. Builders assemble connector X1 so I took that apart to confirm that all the proper wires were on the proper slots.
I has already checked out the HIC connector and it was good.

In the process of looking at the instructions that the folks in this thread had given me, I realized that I had previously interchanged HIC and HIC-B. In looking at the instructions - 46iS-10, there it was: "broke wire in #12 pin, repaired 9/20/20". Pin 12? Pretty critical. What are the odds that this isn't the source of the problem. I immediately removed HIC-B and tugged on 12 and out it came. From using a VP-50 in the RV-7A I built, knew Marc Ausman had written a great set of instructions on opening this type of connector. Pete searched for it on his phone and found the solution quickly: insert a thin screw driver into one of the two pinch points (the slots in the middle top and bottom) and pry. Out it came, allowing Pete to figure how that pin is oriented and what it takes to lock it after it's inserted. We snapped the connector into the locked position, Pete gave a tug on the wire. Yahtzee.

We put everything back together, I got in and turned the key. Nothing.

Fortunately, I knew right away that I hadn't reconnected the HIC connector. Did that and turned the key.

The propeller spun.

Removed the wing spar locking connection, turned the key, no spin. Pressed the override switch and turned the key (not sure why you'd do this in real life) and it spun.

It's a good feeling to solve a problem. It's a better feeling to be reminded of the very good friends I have on Planet RV and online.

I hope I can pay it all back someday .