Need some help....Have ‘89 Iroc,350 TPI, with dual cooling fans. Trying to find the coolant fan switch between cylinder 6 & 8. Applied 12v to broken wire that obviously came off the switch and secondary fan motor works fine, but can not find the broken switch location for the life of me. This is what I find, looks like a plug or the fan switch broken off?

That’s a pipe plug!

Thats a plug. If the switch were broke off, you'd still have the hex body used to crank the thing in. Remove plug, screw in switch.

Thanks guys, will figure out the size of this stupid plug and get the switch!

Some are 3/8 so you can use a 3/8 extension and ratchet.

https://www.thirdgen.org/forums/cool...ches-part.html
Sw555 is a good choice

Sounds good thank you. Tried getting the 3/8 in there and couldn’t do it, seemed a bit too big. Going to pick up a 5/16 tomorrow.

Looks like someone has replaced the heads, and didn't bother to remove the plug so they could put the switch in.

The other head has the temp gauge sending unit in that same hole. Before electric fans, the driver's side head always had the sending unit, and the pass side one got plugged.