A

asw20c

Well Known Member
My airworthiness inspection is schedule for a week from now so I'm trying to get all the last minute details resolved (magnetometer calibration, ADAHRS calibration, fuel sender calibration, etc.) I've been successful in getting rid of almost every red X on the GDU at this point, but the one thing I haven't resolved is my RPM indication which reads 0. All other sensors are working fine (EGT, CHT, Fuel Pressure, Manifold Pressure, Oil Pressure, Oil Temp, etc.). I have 2 PMags, a G3X Touch and Vertical Power system. Per the EMag manual I ran a wire from the #6 pin on my right magneto connector (the tach signal pin) to the number 8 pin on the J243 connector on the GEA24. I believe the PMag outputs two pulses per revolution but it can be configured for 1. I have tried both settings on my G3X (single pulse, and 2-pulses per revolution for an electronic magneto) but neither seem to make a difference. It still reads 0.
Anyone have a similar problem? Your solution? Ideas?
 
asw20c said:
My airworthiness inspection is schedule for a week from now so I'm trying to get all the last minute details resolved (magnetometer calibration, ADAHRS calibration, fuel sender calibration, etc.) I've been successful in getting rid of almost every red X on the GDU at this point, but the one thing I haven't resolved is my RPM indication which reads 0. All other sensors are working fine (EGT, CHT, Fuel Pressure, Manifold Pressure, Oil Pressure, Oil Temp, etc.). I have 2 PMags, a G3X Touch and Vertical Power system. Per the EMag manual I ran a wire from the #6 pin on my right magneto connector (the tach signal pin) to the number 8 pin on the J243 connector on the GEA24. I believe the PMag outputs two pulses per revolution but it can be configured for 1. I have tried both settings on my G3X (single pulse, and 2-pulses per revolution for an electronic magneto) but neither seem to make a difference. It still reads 0.
Anyone have a similar problem? Your solution? Ideas?
Click to expand...
This may not be your problem depending on your wiring, but I initially did not have an rpm indication from my p-mag, which is wired like yours. It turned out the wire to the p-mag was a shielded wire with a very small inner shielded wire inside. I had neglected to remove the insulation from the inner shielded wire. Once I removed the inner wire insulation revealing the tiny inner wire, I was able to get the rpm indication. Good luck.
 
Funny, I’ve seen this a number of times where someone used a shielded wire thinking it was a standard wire, always a WTF moment !
 
MED said:
This may not be your problem depending on your wiring, but I initially did not have an rpm indication from my p-mag, which is wired like yours. It turned out the wire to the p-mag was a shielded wire with a very small inner shielded wire inside. I had neglected to remove the insulation from the inner shielded wire. Once I removed the inner wire insulation revealing the tiny inner wire, I was able to get the rpm indication. Good luck.
Click to expand...
I can't say that I know whether it is shielded or not. It was a wire provided by SteinAir in their wiring harness that came with my panel-build. They knew my setup, i.e. PMags, and it was indicated as a tach wire on their wiring diagram, so I would think they would know what type of insulation is appropriate, but I don't want to assume anything.
 
asw20c said:
I can't say that I know whether it is shielded or not. It was a wire provided by SteinAir in their wiring harness that came with my panel-build. They knew my setup, i.e. PMags, and it was indicated as a tach wire on their wiring diagram, so I would think they would know what type of insulation is appropriate, but I don't want to assume anything.
Click to expand...
This is a shielded wire, and will show that on your diagram as well. Check to make sure you cut the shield back and that the connection is on the center conductor. If you have any questions on this give me a call on Monday or you can message me directly.
 
  • Like
Reactions: MED
Experienced exactly the same thing on my 14A build. Same setup from the same vendor. I couldn't find the problem so I switched the output to the second P-Mag and now have RPM. After reading these posts, I don't think Stein's involvement is relevant. I expect when I look again, I'll find that I prepped one wire inadequately and the other correctly.
 
bobrath said:
Experienced exactly the same thing on my 14A build. Same setup from the same vendor. I couldn't find the problem so I switched the output to the second P-Mag and now have RPM. After reading these posts, I don't think Stein's involvement is relevant. I expect when I look again, I'll find that I prepped one wire inadequately and the other correctly.
Click to expand...
Sounds like we need to come up with a new way to help communicate that these wires are shielded. Maybe we need to strip the shield back at the end of the wire to expose the inner conductor?
 
FlyingSquirrel said:
Sounds like we need to come up with a new way to help communicate that these wires are shielded. Maybe we need to strip the shield back at the end of the wire to expose the inner conductor?
Click to expand...
Thanks Joshua. I'll try stripping back the insulation tomorrow and see how it goes. I'm glad you are on the forum to provide this kind of feedback.
 
asw20c said:
My airworthiness inspection is schedule for a week from now so I'm trying to get all the last minute details resolved (magnetometer calibration, ADAHRS calibration, fuel sender calibration, etc.) I've been successful in getting rid of almost every red X on the GDU at this point, but the one thing I haven't resolved is my RPM indication which reads 0. All other sensors are working fine (EGT, CHT, Fuel Pressure, Manifold Pressure, Oil Pressure, Oil Temp, etc.). I have 2 PMags, a G3X Touch and Vertical Power system. Per the EMag manual I ran a wire from the #6 pin on my right magneto connector (the tach signal pin) to the number 8 pin on the J243 connector on the GEA24. I believe the PMag outputs two pulses per revolution but it can be configured for 1. I have tried both settings on my G3X (single pulse, and 2-pulses per revolution for an electronic magneto) but neither seem to make a difference. It still reads 0.
Anyone have a similar problem? Your solution? Ideas?
Click to expand...
Update: Indeed, the tach signal wire was shielded. Today I peeled back the shielding and stripped the center conductor insulation to get at the wire inside. I connected that back up to pin 6 of the PMag connector and now it works just fine. So yeah, for non-wiring experts like me, perhaps SteinAir could add a note about making sure to make the connection on the center conductor and not the shielding like I did. In hindsight it appears self evident, but with my old eyes I didn't notice that the shiny stuff at the end of the wire was shielding and not the conductor.
 
You must log in or register to reply here.