I know it doesn't make sense but when I took my motor out 4 years ago I can't say I remember seeing a wire & connector going to the PS cylinder head fan switch. My car orginally had a single setup and I've also went to a dual fan setup. NOTE: My 2 fan setup is done with a 2nd fan controller and was working fine before I pulled the motor 4 years ago. SO now to the present. I'm in process of hooking everthing back up and peeling off the blue taped labels I put on everthing while connecting to sensors & etc. I CANNOT find a connector to connect to the PS fan switch on the cylinder head. Is it possible I don't remember the connector because my 91 350 Z28 didn't have it????

 

So I guess your '91 350 TPI only came with one fan because it's a 1LE car with the AC delete? Otherwise, the TPIs should've come with dual fans.

So with one fan, it: 1) was operated soley by the fan switch in the head, like the LO3 cars; 2) was operated by the ECM like the main fan of the dual set-up; OR 3) was operated by the ECM like the main fan of the dual set-up and used the fan switch used as a 'back-up' should anything fail in the ECM program.

And given that the switch itself IS in place(you just can't find the wire), my guesses would be choices 1 or 3 above. Because if the switch wasn't to be used at all, I doubt it would've been installed, and a plug would've been installed instead.

So by deduction, if one of those choices is correct, then there would definitely be(or have been at one time) a wire somewhere in your engine bay that goes to that fan switch.

I was gonna respond to this yesterday. But since my response might not provide a definite, correct answer, I thought I'd wait to see if some of the experts had something to say. But since no one's responded yet... there ya go. I hope it at least provides a starting point.

 

LAFireboyd, thanks for the input man. Any response is better than no response in my mind. I was a bit embarassed honestly to post this. This is the 3rd third gen I've built, this one being the most extensive project and I was soooooo good about labeling all wires / connectors, taking pictures (over 200 pics) and then wahlaa....I literally cannot find the fan switch connector. I'm not one to cut any wires either. I may reroute once in awhile but I don't cut. I've gone ahead and looked for a solution and seemed to have found one. Jet has some parts on summit (and other sources) that has switch, connector / pigtail and all necessary hardware to run. I'm going to research my wiring schematics again and see how simple it is to make a new lead / harness to make it work. FWIW, my car as a 1LE did only come with a single fan (as I'm told all 350 automatics did). I switched to a dual fan (secondary fan being controlled by a raditor temp fan switch) because my ATI Procharger crankshaft pulley interfered with the single fan location.

 

My connector was burnt up by a header, I just used a single pin weather pack. It's not right but it works, is cheap and autozone has it. Then just run a wire to the fan relay... assuming you have one for the secondary fan.

 

yes its most likely burned, manifolds can do it too