Done a lot of reading but first time poster. I have a 99 with an FM2 gt2560 kit. I recently installed a MS3PNP. Install and set up was a breeze. While attempting to set up idle tune and do all the basics, my fan refuses to turn on.

I am running a mishimoto twin fan which I hardwired into the factory harness. I ran that set up for over a year with no issues. Now that I installed the MS the fan will not turn on. It says the fan is on in tuner studio but it is not (the factory relay is good I checked there first)

I tried the programmable outputs and the fan control both using PWMout2 which should control fan. (Pictures below)

Any help would be greatly appreciated. I didn't want to post a dumb question but I just can't figure out how to get the fan to come on.

Thank you

 

Did you check the relay and the fuse, or confirm you’re getting power to the fans?

 

I will check fuses when I get home but don't recall seeing a "fan" fuse on the 99.

 

I believe there's a relay in the box by the washer fluid tank. I had a similar issue that turned out to be the connector at the fan.

 

So... here was my fix (insert🤦‍♂️). I ran a port test until the fan came on. Port injector j ran the fan. Everything is happy now and fan comes on at 195f.

Thanks for the ideas, which ultimately lead me to my fix.