I have been running both fans, but now I have a bigger radiator and want to put one of them onto the temp switch that came with the fans. So, I have this sensor that is supposed to screw into the block or manifold somewhere, but the ports are either too small or too large.

I am wondering if I can splice into the wire that runs to the gauge temp sensor, or if that is some totally different type of sensor? I have the feeling that the relay is what turns on/off the fans, not the sensor. That it (the sensor) only supplies some level of resistance... how close am I?

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

the temp sensor is a variable resistor so to speak. the fan switch is an on/off switch. they are completely different. you cannot use the sensor to control the fan.

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85 IROC 350 11:1keith blacks,.555lift erson roller cam,1.5 crane roller rockers,edelbrock intake,holley 4150 750dbl pumper, nitrous oxide,full length heddman headers,true dual exhaust, 11"stall converter, 700R4, 3.73 locker

 

The fan switch goes in the passenger side cylinder head, between #6 & #8 cylinders.

I need a square drive socket to get the plug out of there on my heads, what does anyone else use?

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Working on:
'84 Z28 LG4 305 with 200,000 original miles!
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350 (ZZ430)
using primarily GMPP parts.
Short block sitting on a stand. (Man, those Fast-Burn heads sitting on it look good!)

Starting to look like the Kicker poster child!

ASE Certified Master Tech

 

JHP,

A 12-point socket will fit the square fairly well if you get the correct size. Since I have a set of 8-point sockets, it's not an issue, but a 12-point 7/16" fits a 3/8" square pretty snugly.

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Later,
Vader
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"What a Day..."
Adobe Acrobat Reader

 

The temp sensor is two wire: one is a constant voltage and the other is a variable ground - variable on temp of course. The switch is only one wire: once the coolant reaches a certain temp it switches off (or on not sure which). You can use variable temp sensors to control the fan (like hayden, derale, etc) though.

 

The fan switch will have one wire.It is a ground wire.When the coolent reaches the right temp it grounds this switch.When this wire is grounded it activates the relay.
I have spliced a wire into this fan switch wire.It goes to a toggle switch.The wire coming off of the toggle is grounded.When I want/need the fan I just throw the switch.When I don't need the fan it is switched off.But this way the fan will run as it should.
Most anytime you have a sensor screwed directly into the block and only see one wire you can be sure it is a ground.Take a dummy light temp sensor for example.It has one wire.this wire is a ground. The positive side of your temp light has power when the key is on.If the temp raises to high this switch will be grounded.And completes the circuit for the light.Thus causing the dummy light to light.
For example, take a thermometer that has a hand,not the fluid type.You can see a metel strip that is coiled.As the coil gets hot it stretches.Causing the hand to move.Inside the switchs they have a small metel strip that as it gets warm it moves until it can't move anymore.When it can't move anymore is when it is grounded against the inside of the switch.

You guys will have to forgive me for this...I'm bored out of my freaking skull and need to get ready for work.
See ya!


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Since my dragon pic won't work I'll have to live with this...
Kevin S
89 RS w/2.9
modded some but not heavily