Jabiru 3300 tach problem ..

[Snodgrass78]

Jabiru 3300 tach question:

 The Dynon D180 installation manual informs me that the Jabiru 3300 tach is connected with "EMS  :-/pin #32, green  and white wire, to one of the white alternator output wires through a 1-amp fast-blow fuse."

  O.K, that's how it was wired. I assumed that it meant to establish a firm (soldered, etc.) connection to that white alternator output wire rather than being wrapped around it as a pickup, so that was done. The problem is that the 1-amp fuse consistently blows when the master switch is on!

 Any suggestions?

 -- Ol' Frank

 

[dynonsupport]

The fuse is there to prevent any faults inside the EMS from taking out your whole alternator. If the fuse is blowing, the EMS side of the fuse must look like "ground." This is either because it's wired wrong, it's shorted somewhere, or because the EMS is broken.

First thing to try is probably disconnecting the harness from the EMS to see if it blows. If it does, then it's not the EMS. If it doesn't, then make 100% sure it goes to pin 32 (use an ohmmeter, not just the color of the wire). If it does go to pin 32 for sure, and only pin 32 (no shorts to other wires nearby) then the EMS is broken somehow.