Ok so im swapping a ls/vtec into my crx si. And
the fan switch exists on the back of that since its a obd0 block
but then the head has a fan switch as well which is right next
to the thermostat.

So so I use the one on the block or rether on the head for the obd1.

Oh and yeah I am running a obd1 ecu. But the obd0 sensor should work
fine as well right?

 

you can use either one your harness probably is wired for the one in the back by the oil filter though. the other one isnt on the head its on the thermo housing. either one will turn the fan on regarless of obd.

 

ok, and do you by any chance know what colors are the wires for that?

or does anybody have a better chart with which color goes to which plug?

 

when i did my lsvtec my fan switch seemed to not work after that. So i just made a manual switch inside my car.