nigelspeedy
Well Known Member
I have a weird thing happening with my RV-8. It has an IO-360 engine and a Skytech starter motor. I used Lamar solid state relays for the master and starter circuits. I have the VPX-PRO and Dynon Skyview system. The aircraft has about 140 hours since new and to date the system has worked great.
On the weekend in flight with RPM of 2500 I started to get an intermittent 'starter engaged' indication on the Dynon engine display. This is a read of voltage on the starter motor side of the starter relay. Luckily the VPX disables the start circuit above 600 RPM. It did not sound like the starter was being activated. I wired the starter annunciator as per the instructions i.e. down stream of the start relay, so it would seem that the VPX was detecting some voltage on the starter side of the relay even though the relay should have been closed/off. When I view the VPX page on the Skyview the start circuit does not show as being activated when the 'starter engaged' widget indication comes on.
I landed and shut down. On the ground with the master still on the starter engaged widget did not come on and the starter did not intermittently engage. When I tried to restart the engine it would not crank.
I looked at the starter switch wiring and when I checked with a multi meter at the starter relay the switch appeared to be operating normally. The starter relay had good voltage on the input side and when the starter switch was depressed good voltage on the output side and also at the input to the starter itself.
When the starter button was pressed the starter made a low buzz or hum but the drive was not engaging. The starter motor and solenoid were warm but about what I expected having just shut the engine down. I could not detect any brown electrical smell.
After taking the starter off and hooking it directly to a battery it ran just fine. Reinstalled and it worked fine but I am still getting the intermittent 'starter engaged' indications.
Long story but the questions are:
1. Could the VPX be inadvertently activating the start circuit above 600 RPM?
2. Could the solid state relay be intermittently activating without the starter button being pressed or the VPX activating it?
3. Could a failure mode of the starter or starter solenoid be causing the 'starter engaged' indication and subsequent issues with not cranking?
Thanks for any ideas.
Cheers
Nigel
On the weekend in flight with RPM of 2500 I started to get an intermittent 'starter engaged' indication on the Dynon engine display. This is a read of voltage on the starter motor side of the starter relay. Luckily the VPX disables the start circuit above 600 RPM. It did not sound like the starter was being activated. I wired the starter annunciator as per the instructions i.e. down stream of the start relay, so it would seem that the VPX was detecting some voltage on the starter side of the relay even though the relay should have been closed/off. When I view the VPX page on the Skyview the start circuit does not show as being activated when the 'starter engaged' widget indication comes on.
I landed and shut down. On the ground with the master still on the starter engaged widget did not come on and the starter did not intermittently engage. When I tried to restart the engine it would not crank.
I looked at the starter switch wiring and when I checked with a multi meter at the starter relay the switch appeared to be operating normally. The starter relay had good voltage on the input side and when the starter switch was depressed good voltage on the output side and also at the input to the starter itself.
When the starter button was pressed the starter made a low buzz or hum but the drive was not engaging. The starter motor and solenoid were warm but about what I expected having just shut the engine down. I could not detect any brown electrical smell.
After taking the starter off and hooking it directly to a battery it ran just fine. Reinstalled and it worked fine but I am still getting the intermittent 'starter engaged' indications.
Long story but the questions are:
1. Could the VPX be inadvertently activating the start circuit above 600 RPM?
2. Could the solid state relay be intermittently activating without the starter button being pressed or the VPX activating it?
3. Could a failure mode of the starter or starter solenoid be causing the 'starter engaged' indication and subsequent issues with not cranking?
Thanks for any ideas.
Cheers
Nigel