Need Some Help

[SDEWY5]

Hi all, didnt know where exactly this post belonged so here it is in forced induction..

my dilemma, had a 5" Splitfire tacho in my car, so today im installing the Autometer Cobalt tacho the same way as any old tacho, Constant power, ground, signal wire and illumination wire all good so i thought til i turned it on. No illumination, if i turn on the illumination the tacho goes to display the shift point and shift light comes on. revs arent accurate to my true RPM (though i expected this as it came off a 4 cyl wrx) but also doesnt have any switch to select 4 6 or 8 cylinder as your regular aftermarket tacho does. i dont know why the hell its behaving so strange.

The back of the tacho has the following wires, And how they (so i think) correspond.

Black - Ground

Red - Constant power

White - Illumination

Green - Signal wire.

Also there were some tiny wires coming from the back which were 2 blue and 2 red (very small not sure what they are for but on the car they came off they werent connected and everything worked fine).

Im stumped if any1 knows what ive screwed up lemme know...

Cheers!

[SDEWY5]

Cheers for the help lol...got it sorted

[STATUS]

yeah those 3 small wires are the tacho calibration wires, 4, 6 or 8cyl.