I just installed an Apexi EL series tach. I got the external shift light that plugs into the back of the tach. The warning (shift) light works on the face of the tach but will not trigger the shift light. There is just always voltage on one of the two wires going to the light. If you plug it in the right way the light just stays on all the time. If you reverse the poliarity it just stays off.
There is a small resistor (i'm guessing by the shape) under the shrink tubing on one of the terminals of the LED. should i try a diffrent one of the same value?

any ideas or experiances would help. Also the needle jumps when at full throttle but is smooth just cruising. I used the blue wire on the drivers side of the fire wall. could these problems be related? TIA

 

Can anyone test the shift light leads on the back of your Apexi tach? Do you get voltage when the warning triggers? Mine is brand new and I need to see if it is defective. peace