I'm installing headers and I found these sensors with nothing attached. I do have wires that appear would have connected to them but the plastic is brittle and they seem to be missing a connector.....I know the plug for my 02 sensor in the middle pic but that other wire has me clueless...any ideas?

 

1st look like temp gauge sender ( for dash )
3rd appears to be is a fan switch
The green wire hanging in the breeze would be for fan switch ;

 

thanks...this might explain why my temp gauge redlines every now and then

 

after further investigation it appears the sensor in the third pic is the knock sensor and the green wire is for the temperature sender

 

checked again......third pic IS the fan switch....my bad. Green wire is for the temp sender between cylinders 1 & 3

 

Is the wire green with white stripe? If it is, it is the fan switch wire. If it a stock l03 you need it for the electric fan.

 

yes it has the white stripe....from my searches I learned this switch is allegedly solely responsible for turning on the fan if the ECM or coolant emp sensor fails

 

If that is not connected, you fan will not come on unless the previous made some mods to by pass the switch. Your engine will over heat if you are stuck in traffic, or driving under 35 mph. I'd replace the temp switch, or just reconnect it in short order.

 

wait.... theres knocking sensor... around driver bottom side... then theres gage temp between cilinder 1 and 3... but theres another one? this might explain why i need to leave my AC on all the time lol... i thought the coolent temp sensor sent data to the ECu and that activated the FAN

 

the green wire in the pic was is on the driver's side, for the sender. And I agree 007.....from what I've been reading here that switch is like a backup if the ecm doesn't turn the fan on. Mine crumbled when I removed the manifold so I installed a new one with a new connector

 

The ECM has nothing to do with the fan on your car. Will only go on with fan switch or by turning on AC

 

ohhh... so wheres the fan switch?

 

See where the temp sender for the gauge is between #1&#3 plugs? ( Pic #1 )Imagine turning the head around and putting on the pass side. Now the hole is between plugs #6&#8. That's wqhere the fan switch goes. Should have a green with white stripe wire going to it

 

awww reachind down there sucks... smog crap all over the place =[

 

passenger side above the knock sensor

it's in essence a relay. When the coolant hits a certain temp it closes and power goes to the fan.

The drivers side is for the temp gauge.

I suggest a Hayden adjustable fan controller. They are cheap at amazon and easy to install

 

jb, did you trace the green /w white stripe wire to the relay on the firewall? If you look on the drivers side firewall, there is a relay that turns the fan on when the engine gets hot.