Aftermarket Tachometer?

Hey guys just entered these forums, mainly because i've been tring to install an aftermarket tach in my 92 Nissan Sentra XE (2 door no factory tach.) The link to the tach I bought is listed below. Ok Ive got all of the wires hooked up but the tach signal. Ive tried the green/yellow strip wire on the ignition coil but it didnt work. But I may have to try it again because im not sure if my connections were good. But any advice would be deeply appreciated. Oh yeah the tach does light up so that must be a sign that it works.



http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=005&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=150109080930&rd=1