Hi,
I bought a 86 Cameron z28 Iroc which apparently the prior owner added a manual switch below the steering wheel. She/He also added a temp gauge too. The gauge in the instrument panel does not measure the temp. I would like to get it back to factory settings. It is a single fan set up. Any advice in where to start? Any advice appreciated!

 

I ran into the exact same thing with my 86' What I did on mine was find the green/yellow wire{ it ran along the pass side engine harness on top motor} it should have a female spade end. there should be a factory sending unite installed in the intake kinda behind the water pump, That will run the temp gauge. On my car the temp gauge would peg every time I started the car so I pulled the gauges apart and super glued a old gauge pointer at the highest point of the temp gauge, Now when it pegs it hits the pointer and goes back down instead of sticking.

 

Your car didn't come with an electric fan, which is why it's such a ruthless hack job.

It came with a clutch fan. I'd suggest putting that back, with a thermostatic clutch and a GOOD fan. (NOT a "flex" fan) Make sure the shroud is intact and the fan fits well in it.

To properly retrofit an electric fan, you need a relay with contacts that can carry about 50A, a temp switch, and some decent wiring skillz. The relay should be wired with one side of the coil going to switched ignition (hot in run ONLY) and the other side going to the temp switch which should be installed in the pass side head. Temp switch grounds that wire which then operates the relay. Those wires can be quite small since all they carry is the relay coil current, well under 1 amp. One contact of the relay should be wired to a HIGH POWER source of battery, with BIG FAT wire; I'd suggest, for the sake of ease, #10 wire connected to the big post on the alt, with about a 50A in-line fuse right at the post. The other contact of the relay should then go to the fan with a #10 wire. Mount the relay in a place that all the high-power wires can be as short as possible, which in your system, would be near the radiator on the pass side. The other side of the fan motor should be grounded to the engine block with a piece of #10 wire. Get rid of the toggle switch and the aftermarket temp gauge. Above all, DO NOT try to run the full fan motor current through a toggle sw without a relay; that's a great recipe for burned-up parts, melted wiring, sitting by the side of the road with an overheated engine, etc.

Without knowing what sort of fan has been hacked into your car, it's impossible to guess whether it's adequate or what; you could possibly wire it all up perfectly, and still have GARBAGE for a cooling system. No way to know.

Factory temp gauge wire is dark green; runs along the driver's side of the intake next to the valve cover, goes over the VC about at the PCV valve, and plugs into the sending unit which is in the driver's side head between the #1 & #3 spark plugs. Your car won't have the factory electric fan wiring since it didn't come with that.

 

Thanks Sof,
Very helpful information! In the picture that I have attached, is that factory temp gauge? I know is yellow but at the base there is a dark green wire too? It seems that is b/w 1-3 spark plug. Is that part of their hacking job too?

 

Yup, looks ... rather ... alternately engineered.

But yes, those are indeed the parts in question. Now, the next question will be, what else did they hack; for example, did they take out the temp gauge sending unit and put in a temp switch, and hack the wiring somewhere further upstream; or what? Enquiring minds want to know.

I have NEVER understood the attraction of hacking up cars' wiring. Total mystery to me. Just another oddity of this species I'm stuck living among for the duration of this assignment; these ... humans. Those ones that think they're the most intelligent life form on this planet.

 

I know! Where can I start the investigation?

 

So I got under my car and found the radiator fan switch, but it has a blue wire pigtail connector. As stated above, the previous owner of my car installed a manual switch to the fan. Is it possible that radiator fan switch is working at the same time with manual switch as well?

 

post a picture of it.

If the P.O used a manual switch, then the they probably just left what was there and bypassed it.

 

You are correct! I just got underneath the ca3 today. Ground the pigtail to the switch and there is no electricity. Do you think they have a rely somewhere I should check? What should the next step?

 

The radiator fan switch wire is not blue.

Sounds like you found the knock sensor, whose wire IS blue: it's in the pass side coolant drain hole, immediately above the oil pan rail, about at the front of the starter, pretty much exactly at the front-rear center point of the block.

Fan switch wire is dark green w white stripe if memory serves. Factory fan switch would be in the pass side head between #6 & #8 spark plugs... in the other head in the same hole as the temp gauge sending unit.

 

So I check it, nd e green wire pigtail is melted anddont work when I tried to ground it. there is a switch. So should I look for a relay?