Thread: Just finished a motor swap and fans wont turn off.

I just got done putting a 98 sr20 into my 96 200sx se-r. I am using a know working ECU and a good coolant temp sensor but my fans are turning on when the motors turned on. The motor is also ideling high. What else beside an ECU and CTS could cause the fans to turn on?

try another cts just to make sure.
i used to unhook the plug it when i would overheat.

CEL on?

Migt actually be a faulty cts.

Ill change it to another one i have laying around. Ill report back in a few minutes.

Also i changed the ECU out with another know working one and it still has the same symptoms

i just changed the CTS and I am still having the same symptoms.

Its a 3piece harness make sure the 2 main harness is plugged by the tranny. Check if the harness is pulled from the plug connections.

This happens to me with my b13 I just got running. Car running- Fans running, even with a different working ecu. My CTS is brand new oem as well.

Sounds weird but on my old B13 I had the two connectors coming off the alternator harness that look alike reversed. They are the same plug that plug into the connectors by the relay box on the passenger side of the engine bay. My B13 acted all funny with them reversed. Switched them around and the car ran fine, lol. Worth a shot.

I thought the temp sensors need to match for the sensor and year of the ecu?

I fixed the issue. On the main connector that connects the engine harness to the chassi harness. One of the prongs was not making a connection inside the connector.

The car still idles rough. Will jump between 1500 and 1100rpm. I cant get the idle lower then that either.

The car also feels very very slow.