To start off I have a 90 crx dx with a b18a1 swap. I noticed my fan is not turning on which explains the overheating sometimes. My question is, what exactly tells the fan to turn on? When I search b18a1 fan switch I get multiple answers/ things to buy.

from what I have read I have located 2 "switches" on the car. One is next to the oil filter on the back of the block (has 2 prongs sticking out with a rubber boot covering it and where the 2 wires connect). The other is on the passenger side under the distributer which from googling is the same one that on some b18s is on the thermo stat itself.

my wiring is a mess and I am having a hard time following where they each lead to. I am going to jump the fan to see if that is an easy fix but it's pretty new so I want to have other options if it works.

Thank you ahead of time and I hope this doesn't turn into the threads that pop up in the search with different answers.

 

Pull the plug off the thermostat switch, and jump the wires. If the fan comes on with the key on, the switch is faulty. If the fan still does not work after jumping the wires, check your relay wiring.

 

that's the problem I'm running into. I don't have a plug on the thermostat. Just the 2 in my original post. If I use the paperclip trick on the one by the distributer nothing happens. If I do the paperclip trick on the one behind the block then the relay clicks but no fan.

I have read too many different answers when I search so I just want to know if the one on the back of the block is what my main focus should be on. I just want to make sure that the one near the distributer has nothing to do with the fan and I'm getting somewhere with the clicking relay.

sorry if this is confusing, I hate wiring so I'm doing my best to explain.

 

Use a multimeter to see if the relay is powering the fan. Also check if the fan motor is grounded.

The switch should be on the block for a b18a1.

 

that is the correct plug. and since it is turning the relay on, the fan motor is likely dead or disconnected from the relay.

 

Thank you all. All the videos showed the other switch and when I Google it both switches pop up for me to buy labeled as the fan switch. Hopefully I can get this figured out this week now that I know what path to follow. Thank you again.

 

Have you direct wired the fan from the battery to rule that out before you start chasing a phantom?

 

not yet, I will when I get a chance after work this week. I would rather know other options if it doesn't work or if something goes wrong in the future.

since the relay clicks I'm hoping it is just the fan motor or the wiring between the two.

 

Did you get this fixed?

 

not yet, work has been keeping me busy as hell. The weather dropped a lot so I got time lol hopefully I get a chance this weekend since this is my daily and only have a small amount of time during the work week.