Hello, been working on this 89 Iroc for the last few years and finally got it running. Have a plug on the Passenger side of the engine that I can't find a place to put it. There is two plugs there as pictured with one going to the knock sensor(it will be relocated to the drivers side due to header). It's the other one that is in question. Looks to not been hooked up to anything for a while from the looks of it. Any ID on this would be appreciated. Thanks

 

Fan switch. They're the same type connector, one is black, the other is white. At the moment I can't remember which is which.

 

Obviously, one of your connectors is broken. You can get a replacement pigtail at most any auto parts store.

One is the HD coolant fan switch (should be a dark green/white wire).

The other is the knock sensor (should be a blue wire).

Please confirm the wire color with your model year service manual or other trusted reference.

 

Thanks for the info. Local parts store has a pigtail in stock. I am assuming these don't turn the fans on until about 230. Would like them to come on sooner. Does the sensor ground at that temp? Could an aftermarket fan switch do the same thing? Any factory sensor work sooner? Thanks

 

There are lots of aftermarket fan switches with different turn on temps. Do a search on this board for fan switches
OOPS, sorry I was forgetting where this is. Search on the cooling board instead
Like this for example
https://www.thirdgen.org/forums/sear...archid=9178088