88’ GTA new 355 engine. LS fan assembly with stock wire harness. Not started engine yet but was doing an IAC cal. I go to key on and the drivers side fan is on. I put a new fan switch (goes between cylinders 6 & 8). Is it possible the new switch is bad causing it to ground causing fan to come on?

Fan switches come in normally open and normally closed flavors. You may have the opposite of what you need.

Thanks Komet! I thought all were ground is on so let me check that.

So switch is Summit SUM-8901117 supposed to be on at 185deg/ off 175.

ok unplugged switch, fan still runs so may be something else.

@Tuned Performance thinks it may be in the a/c pressure switch setting so he’s checking the tune.

Just checked, old tune and new tune have n/o fan switch selected. I’m wondering if the tune is bad on the chip or bad chip on the adapter.

We’re still chasing this. So install just memcal and the fan does not come on. @Tuned Performance suggested reflashing start up tune so did that. Reinstalled and again fan on with key on.

Update- I installed an old chip I had from @Tuned Performance and the fan did not come on at key on. @Reddragon88gta suggests its a Bin stacking issue so hopefully we can get it sorted. I want to get my new engine fired.