I have a 1999 Miata with a DIYPNP, FM turbo kit, and a square top installed. I have had the DIYPNP installed for about 6 months and the IAC valve was working just fine until i installed the square top and turbo about a month ago. Since then I have not been able to get my AC idle up to work at all (it was fine before). I measured the iac connector and I am not seeing 12v or a switched ground. There are 2 unused plugs from when I installed the turbo and manifold but one of them is from the old O2 sensor and I believe that the other is from the VICS solenoid. Any help is appreciated. Thanks

 

Did you forget to bolt back up a ground wire?

 

I believe that the IAC valve is supposed to run off of a 12v positive source and a switched ground so I don't think that is the issue. But I am pretty sure there was only the one ground wire that connects to the bracket that holds the 2 halves together and I put that one back on.