So I bought this two wire temp sensor and pigtail in an effort to rewire my fans back to the factory setup. The pervious owner had it wired as an in dash switch with no fuse or relay! So I bough what I though was the right part, it's part number su102 from autozone. I installed it but cannot for the life of me figure out what wires connect to it. I was able to rewire the fans back to the original relays that we're just laying their and I traced the wires up along the passenger fender and can't find any loose wires that look like they were for the temp sensor. I'm really stumped in this one and any help is appreciated. Thanks!

 

Most of the single wire systems connect to a sending unit/sensor/switch that gounds the wire when the temp reaches the pre-set range, 230F on a stock set-up. That sensor/switch is located in the passenger side head, and has one wire going to it.

There were a few thirdgens that had a two wire sending unit screwed into the front of the intake manifold in the water jacket. My 86 TPI car has that configuration. On the two wire set-ups the sensor connects the two wires completing the circuit which comes from and returns to the computer. Completion of the circuit acitvates the fan, or fans.

It sounds like you have a car with a single wire system, and someone has sold you the two wire sensor/temp switch. You can connect the one wire on your car to one side of the sensor/switch. Connect the other terminal on the sensor/switch to chassis ground, and it should work fine. All you are doing is completing the ground circuit back to the fan relay.

If it were my car, I would install an aftermarket sensor/switch that activates the fan at 195F. It will have the single wire connector, and work the same way as your original sensor/temp switch, only it will activate at a cooler tempature and if your cooling system is working well, your car will run cooler.

 

The fan switch wire is located in the engine wiring harnese. You won't find it on the fender. I believe that it is green with a white stripe. The solid green wire on the driver's side is the one that attaches to the guage sending unit in the driver's side head that works the temp guage on the dash. The two circuits have nothing to do with each other.

If the PO took the wire that goes to the sensor/switch and wired it to a dash switch, it would be a simple process. The manual switch would provide a ground to the wire, and this will activate the fans. Of course, there is no guessing what kind of arrangement he may have rigged up.

 

Those colors sound about right. The wire should come out of the harness that runs along the intake side of the pass valve cover. It ordinarily drapes over the VC. Should be a round Weatherpak style w a single pin.

Sounds like you have the wrong part; IIRC the right one is some # more like SW500.

 

Thanks so much for the replies! I tried to chase down the green/white wire but I ended up buying a whole new adjustable fan switch system from summit for 40 bucks. It fits in between the radiator to get te temputature. I gutted my old fan system wires, relays, ect. I also got a little carried away and tried to gut my a/c wires too and delete my Evap canister. Ow my fuel pump won't prime. The car still starts but It takes a few seconds and its throwing a code. Does anyone know what wire primes the pump? It would most likey be by the passengers side valve cover because that's where I was messing around the most.

 

A1 on a 1227165 ecm controls the fuel pump relay for the 2 second prime.

 

 

The I cant see the picture for some reason but I'll trace the a1 Pin and see where it takes me. If I disconnected the Evap canister wires would that stop the pump from priming? I might just plug it back in and see why happens. I only took it off because I want to do a custom cold air intake eventually where the Evap canister sits. I've just been obsessed with cleaning the engine bay lately and it keeps getting me in trouble. Lol

 

The evap purge solenoid has nothing to do with the ecm controlling the fuel pump relay. Maybe you can see this schematic. The ecm when powered on send voltage out A1 to D of the fuel pump relay. This is a dark green/white stripe wire. The prime is a 2 second prime.

 

Wow that diagram is worth it's weight in gold! Thank you so much. I found the wire yesterday when you told me it was the a1 pin. And I deffinatly cut it so I wired it back up and it worked! Thanks again so much and I'm totally saving that diagram. Lol, and my adjustable fan controller came in today so I'll wire it up and post my results with it.

 

I read a post of yours a while back were you bought a memcal. You can reprogram it very easily and set your own on and off temps. I like to set the camaro to turn on at 200f and off at 185f.

 

Yea I bought one but I don't have the programming tools yet but it's on the list of upgrades. I've been lookin into this computer actually. It seems pretty user friendly and from what I understand their is no chip burning required! http://www.dynamicefi.com/EBL_SFI6_Flash.php