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Wiring /Fault issue Dual P Mag

On my IO 390 wired as per P Mag instructions , all satisfactory with 12V at pin 5; however, second dual P Mag at switch to P in 5 12v initially, however once live to pin 5 voltage drops to less than 1/2V both at switched terminal and at pin 5 on the P Mag. Changed switch and removed switch still the same low voltage once connected to pin 5 .Do I ave an earth fault on the second P Mag? Voltage supplied via VPX and wired as per manual. Fault found during P Mag timing process. Wired with P Mag isolation 12V power switches and individual VPX circuits and separate kill switches. Any help or suggestions appreciated.
Thanks Mike
 
I suggest:
- Verify you have the pMag grounded per the instructions.
- Connect a temporary wire from the battery, through a 5amp breaker, then to the pMag power input. This removes the VPX as a variable. If the pMag works, then solve the VPX problem.

If no joy on these, then call Brad a eMag.

Carl
 
Question

Is there a compelling reason to wire the pMag ships power through the VPX? We deliberately did not do that so in the unlikely event of a VPX failure - we could still get the engine started and possibly get back home without the VPX.

Not saying this is a bad idea, just trying to understand the logic in your decision.
 
Wiring Dual P Mag: Answers

Removed 6 pin connector from P Mag and able to obtain 12v at pin 5 Bat. Fault reappears on reconnection of the 6 pin connector to the P Mag. Hence VPX not the issue.
Have contacted Brad at E Mag.
Re power supplies and VPX, I have a separate power bus to supply other devices
not supplied by VPX due to physical design limitations, this has a spare wired CB that can be wired to any suitably rated device as a on the ground get you home emergency
option. Use would be dependant on safety and risk mitigation.
Thanks Mike RV 14
 
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