Hi Im Sipoon glad to be here to have some discussions with pro.
I have first gen 1989 b16a. Now my question is my thermo switch is compatible with b16a2 or other gen?

 

When you say "thermo switch", are you referring to the cooling fan switch ? If so, yours would be mounted on the back of the block under the intake manifold and close to the alternator. All "B" series engines from 1994 to 2001 are smaller in size and mounted in the thermostat housing. They also have a different plug style. If you acquired a thermostat housing from a modern "B" series engine that matches the combination of cooling lines on it as you have now, you could install that and extend the wiring from your original switch/sensor area and change the plug and it would function just like stock.

 

Yes and i think im using obd2a engine harness in my first gen b16 i saw a socket near the thermostat housing and i think they just bypass it going to the block to reach the thermo switch. Maybe i can use that socket if i change my thermo switch into modern b16a?

One more thing, coz im having a problem with my rad fan it doesn’t turn off if the engine is on operating temp. But I didn’t experience any overheating while driving the car its just running continuously even im in the idle. I tried also to turn off the engine and just key ON and the rad fan is still running. But every cold start ofc its off.

 

If you are using a more modern engine harness on an OBD-0 style B16A... yes, you would do the OPPOSITE of what I stated above. The engine harness would have a two-wire round plug (green wire and black wire) at or near the thermostat housing. You would then remove that plug and extend the wiring to the area near the back of the block low close to the alternator and convert the plug to the older style. The fan switch would be working correctly if when you start the engine cold, the radiator does NOT turn on. If you connect the two wires at the thermo switch together, the fan should come on. Otherwise, once the engine has reached the temperature where the thermo switch closes, the fan will begin to run. Unless the engine temperature falls below the threshold where the fan should turn off, it will remain running.

 

Do you think this is the modern socket of thermo switch? I just found it i think?

 

If it has a green wire and a black wire... then yes.

 

I have b16a 1989 but im having a problem with cooling system. My rad fan doesn’t turn off when my car is in the operating temp. But it is automatically turns on if its getting warmed up then after that it doesn’t turn off. I replaced the relay, tried to jump using paperclip the two wires of thermo switch it runs, no overheating issues because i tried to run in high rev but the temp gauge still the same. Do you think what is the problem?