I just recently swapped from an H23a1 and I'm reusing the wiring harness and my JDM H22a doesn't have the thermoswitch on the front water outlet that the top radiator hose connects to. I'm also using the JDM P13 ecu and was wondering does the JDM H22a use this thermoswitch, will the ECU look for it? My fans are coming on normally and I drove the car and got normal temp readings I'm just wondering if I can get buy without having this since I cracked the one from my H23a1. It's #11 in this pic...

 

thermoswitch is not ECU driven but coolant temp. that one on the front helps to avoid the head overheating when the engine is off.

 

#17 is the vital switch that you need to run the fan. Thermoswitch B on the outlet is closed above 223f on another input to the fan control module. You're fine running only the fan switch on the t-stat housing.

 

what is the part # 14 for? Is it a bleed screw?

 

^Yes it's a bleeder so that when you fill the car with coolant you can just keep on pouring until a steady stream with no bubbles come out. I figured I was fine not running that switch, the JDM motor has the outlet where you could drill and tap to add the switch but it wasn't there. I did notice the first time running the motor the fan came on after turning the car off though when it didn't even get a chance to warm up so I may eventually add it after my bank acc recovers from this swap. =p