Hi

So i have an 87 t2 and im trying to tire up an aftermarket thermo switch from sumit racing etc i need to tap into an ignition wire under the dash dose anyone know what wire is it?

 

You shouldn't need to have any thermoswitch wiring in the cabin. Put it in the engine bay along with the relay and fuse powering the fan. There are plenty of places to get switch power from in the engine bay, but the easiest is to plug straight into the green 6-pin diagnostic plug next to the leading coil. It's the black/yellow wire.