Mornin' I'm pretty sure that i'm not the first to try this, so i thought that i would ask the people who drive rotary's for an answer. I have a autometer tach model 3904 that i want to use in my car if possible. My question is does anybody have a connector termination point for the coil wire on a rotary, i couldn't find any reference to rotary installations on the mfgr. website. And the final part of the question is what do you set for the pulse per revolutions at . Or is there an adaptor required. I would appreciate any help with this problem. Thanks Leata

 

i connected my rpm msd switch to the wire on the leading coil upfront and it had a black wire connector where a wire can go. the wire itself is come outa the wire area that goes into the coils the selfs. about your final question no idea.

 

try the 4 cylinder setting.
stock tach still hooked up (if possible to compare) If that doesn't "add up" try the 6yl setting.
there is a bullet connector near the Firewall off the trailing coil(yellow/Green?) it is a single wire.that is Tach signal.

 

i used the leading coil. is this wrong? i have the switch set for 4 cylinder at 3800 and my pump turn on at what seems to be 3900-4000 rpm so 4 cylinder is off by very little

 

Leading coil is fine. The black connector at the leading coil is meant to hook up a diagnostic tach anyway.

 

I mentioned the Trailing coil,as the Stock tach runs off the trailing anyways.Besides it is less of a Run of wire,as that connector is just on the Inside corner at the Drivers firewall.

 

my wire goes to my rpm switch witch is under my hood latch, so it was closer for me the other way in that situation.

 

I was referring to canonize-ryda's RPM switch.