Cooling fans have stopped working
 

Ok Team,
I don't do this often...but I'm stuck and looking for some help. I'm going to put this out in bullet format to make it easier to read.

* Cooling Fans aren't being turned on by the Megasquirt anymore.
* They were working, then I had to pull the motor to fix my weak crank

* They turn on when I short TFA to GND on the connector
* They go off when I pull the relay or the fuse.
* The ECU s getting the temp signal from the cooling system
* The stock gauge is working, but I noticed today that it was moving when I give the car gas.

I have racked my brain about this one for the last hour or so to no avail....so someone tell me what I left unplugged :)

you didn't do anything to your tune?

Does the MS indicate that it's trying to turn the fan on? This would be indicated by a green icon at the bottom of the TunerStudio dash.

How is the MS wired to the fan(s)? Specifically which wires connect between the MS and the vehicle in this regard?

Also, it might be a good idea to re-connect the ground strap that you left off when you re-installed the engine.

Changed nothing in the tune other than the settings to allow me to recheck the ignition timing.

The ECU Is the MSPNP so it is using the factory fan wires which has been working for 2 years now.

The ECU Thinks it's turning on the fans

I have checked, double checked, rechecked the grounds. Even went as far as to add a second ground strap from the Chasis to the engine all with no joy.

Interesting side note. If I pull the main relay the fans turn on.

yeah that's a normal thing because the way it sends power to relays or something.

if GND and TFA works, and the MS things it's turning on fans, either the wiring to the MS is served or the circuit controlling the fans in the MS is burnt out.

I pulled the connector from the ECU and shorted the fan wires to ground and the fan came on. So the circuit from the ECU to the fans is functional. The ECU is getting the CLT temp from the sensor on the back of the head and it is reading correctly. It was working before...kind of at a loss right now.