Electric cooling fan

my Z28 has had a engine swap..and taken old school..but it has a electric cooling fan..the cooling fan doesnt turn on at any temp..........there is a splice on one of the 2 wires and if you touch that to the battery it comes on.....the question is...what controls the fan? the computer ? a thermal-switch?..basically i want to get it working. and i know i could wire in a switch to do it manually ...but i dont want too

one other question where is the fan relay??

guys....i cant drive this until this is fixed...anything would help? what tells the relay to turn the fan on?

The temp sensor

yes i know.....is the fan controlled by the computer at all?? and where is the relay?

The fan relay is located on the firewall driver side (most of the time)
The ECM does not turn on the fan. There is a temp switch in the engine block on the right side just above the starter. Single green or green with white stripe wire. This is a ground that tells the relay to energize the fan circuit

with alot of looking i figured this out.........the pcm has a coolant sensor in the thermostat housing when that gets hot enough the pcm energises the relay which closes the circuit .. energising the fan..............i have a bad relay was my problem

I would put a a stand alone system in it and be done with it.

i thought of that...i havnt a clue where to find such a thing..
the computer knows a whole lot mroe than i thought it did....my dad put his scanner on it....and the computer knows the rpms.... coolant temp...vehicle speed tq converter status......alot of thing! i only pulled three trouble codes...im really amazed

There's a few of 'em out there, some either go to the block or to the radiator and are adjustable.