Piper J3
Well Known Member
I just finishing an uneventful 1.2 hour flight and had a high voltage alarm on the D-180 at 5 miles from final destination. I viewed the EMS screen and saw 14 volts on battery in red arc. I kept manually shutting off the alarm and then landed. All electrical systems were working. High voltage alarm subsided when power was reduced for landing. After landing I reset elevator trim position as I taxied in like normal. Engine shut off was normal followed by the powering down the Master Switch.
I thought the John Deere VR failed now at 245TT. Original Ducati VR failed at 104TT hours but mode of failure then was low voltage and not high voltage.
I have a spare JD VR so I installed by mounting it on the shelf in original location. VR wired correctly and all wiring under cowl looks good.
I turned on the Master Switch and nothing happens. No relay click - nothing.
I detected a strong whiff of electrical smell and quickly disconnected the negative battery terminal. I removed the instrument bay cowling and the smell appears to have emanated from the fuse block/switch cluster. All fuses are good as checked with ohmmeter. I have shined a bright light at the back side of the fuse block and looked down between the circuit boards and don’t see any damaged components. Various capacitors look OK. If I power the D-180 with its backup battery it shows battery voltage at zero with main battery connected. I measure actual battery voltage at 12.9 with a VOM.
I think my next step is to remove the D-180 EFIS and then remove the fuse block/switch cluster for a detailed visual examination. My plane is an early SN so it has the fuse block/switch cluster on the left side.
If anyone has any thoughts I’d appreciate some insight.
Thanks in advance…
I thought the John Deere VR failed now at 245TT. Original Ducati VR failed at 104TT hours but mode of failure then was low voltage and not high voltage.
I have a spare JD VR so I installed by mounting it on the shelf in original location. VR wired correctly and all wiring under cowl looks good.
I turned on the Master Switch and nothing happens. No relay click - nothing.
I detected a strong whiff of electrical smell and quickly disconnected the negative battery terminal. I removed the instrument bay cowling and the smell appears to have emanated from the fuse block/switch cluster. All fuses are good as checked with ohmmeter. I have shined a bright light at the back side of the fuse block and looked down between the circuit boards and don’t see any damaged components. Various capacitors look OK. If I power the D-180 with its backup battery it shows battery voltage at zero with main battery connected. I measure actual battery voltage at 12.9 with a VOM.
I think my next step is to remove the D-180 EFIS and then remove the fuse block/switch cluster for a detailed visual examination. My plane is an early SN so it has the fuse block/switch cluster on the left side.
If anyone has any thoughts I’d appreciate some insight.
Thanks in advance…