Aftermarket tach problems

[Tofudude]

i got me a sunpro super tach 2 and i wired it up just like the diagram and the tach won't even move...but when i do a test straight to the battery the tach works perfectly...somthing i'm donig wrong?

[yotaneck13]

on the back of your tach does it have a bunch af switches to set it for 4 cy or 6 cyl i have the gatornationals version of yours.  also what motor are you putting it on?

[Tofudude]

i have it set to 4 cyl and its a 22r.

[tineye]

Double check your grounds, and make sure the hot wire is 12v switched. Your problem is probably very simple, just double check your work.

[toy4xfun]

aftermarket tachs do not like toyota ignitions, call sun and they should have a resistor or something so it will work.

[Tofudude]

it was a power problem but the thing i can't figure out is that a hot 12v wire for my light wouldn't work but i used a fuse tap on the cigarette lighter and it works all of a sudden...same ground too. Its got me baffled but i got it. thanks yall