L2 wire for tach cluster

[Terry]

I am putting an 88 tach cluster in my 87 non tach truck. I have gages for amp, coolant temp and oil pressure so I am hooking up the tach and fuel gage. I know that the green stripped wire in pinout # 4 is the signal wire. The black wire with the white stripe in pinout # 3 is comming off the other connector for the tach. I have been looking all over the site and can't find info for where the L2 wire goes. The cluster from the donor truck was a single tank truck and my 87 has dual tanks. It looks like I the yellow wire with the white stripe is for the fuel gage. Any other wires on 1-9 pinout need to be hooked up?

 

[SenorNoob]

I'm pretty sure that is the secondary ground for setting the tach to operate on 3 ppr vs 2 ppr. (V6 vs I4). Had to ground it on my truck to get a tach reading that made any since.

 

[Terry]

I'm pretty sure that is the secondary ground for setting the tach to operate on 3 ppr vs 2 ppr. (V6 vs I4). Had to ground it on my truck to get a tach reading that made any since.

Did you hook any of the other wires up other than the fuel gage wire?

 

[SenorNoob]

I don't know anything about the rest of the wires. Just the L2. Mine had a factory tach with just a broken wire.