Hello.
My son just picked up an 87 IROC-Z 305 from someone who picked it up at an Auction.
Yup! Problem after problem!
My question is,
After installing/replacing a radiator fan, it (the fan) wont turn on.
The car just gets hotter till I shut it off.
The other fan was not working either.
I have noticed a sensor sticking out of the radiator directly below the radiator cap. It's about 1/3 to 1/2 way down the radiator.
Is this the sensor that tells the fan when to turn on/off?
The sensor also has nothing plugged into it.
I have searched all over that side of the car with no luck finding a hanging wire thats wanting to be plugged in.
If one of you could direct me to where this wire may originate from, I'd appreciate it much.
Or maybe I'm way off and it's somewhere else?
Any suggestions would be greatly appreciated.
Thanks, Ray

 

a sensor IN the radiator...not for the fan.

 

I just finished reading a few past posts.
Looks like I need to look between cylinders 6 & 8, next to the dip stick.

 

Try thses threads:
https://www.thirdgen.org/forums/cool...an-switch.html
and:
https://www.thirdgen.org/forums/cool...ing-issue.html

If it doesn't have what your looking for, just do a search using "key words" and keep it simple!

 

Thanks Paul.

 

when i had a problem with my fans i just completly rewired the entire fan systems and now i have no problem at all i just ran the wire through the precut holes in my firewall but now i turn my fans on manually

 

theres also a kit you can get. You will need to change the thermostat. It has a sensor you put between the fins and it automatically turns them on once it reaches 180 and turns off when it gets below that. Look on Summit Racing and its a universal thing lil pricey but something to look into.

 

that 's a good idea but i like the manuel fans if i turn them on when i start i'v never seen my temp get above 180 unless in stop and go traffic

 

Yeah, but the problem with manuel fan switches is that if you forget to turn them off you end up killing your battery!!!! And if you have a old battery in your car you COULD end up draining it in 15 mins! That's my

 

tap into the wire that is connected to the fitting on the passenger side, located in the cylinder head.
ground that wire.
if the fans come on, thats your problem.
very common.

 

i'v left them on before killed them in my HS parkin lot left me lookin like an idiot having to get a jump from a FORD that was a plz shoot me moment

 

please explain.

 

quick tip: the coolant temp sensor in the cylinder head does NOT turn on your fans. it only works the temp guage in your car. the coolant temp sensor in you intake manifold DOES turn on your fan.

alright now i had an issue that was a bitch to figure out lol. ok when i baught my camaro, it had a toggle switch hooked up to the fan. so it can be turned on manually. okay so i drove it around like that for almost a year and finally decided that i need to figure out WHY its hooked up to a toggle. first thing i did was hooked the fan back up to its originaly wires comming from the ecm. let it run until it got to about 220 on my GUAGE. nothing, the fans never kicked on. so i started doing an *** load of diagnosing wires, relays, coolant temp sensor. i replaced the coolant temp sensor in the intake manifold (the one that turns on the fans) and restarted it,,,,still no fans!! so i busted out the scanner at work. watched the temp on the SCANNER, when the scanner said it reached 228* the fans turned ON. (i was excited lol) then looked at my guage and it read 260* (the red line). yeah...thats about 30* off lol

so guess what, the sensor in the cylinder head (that only works the guage) was bad!! this whole time its been hooked up to a toggle and there was nothing wrong with it. when i thought it was over heating, it never was haha

so the answer to your problem is, get a scanner and see if its actually reading the same temp as your gauge does. if it does, then swap out the coolant temp sensor in your intake manifold. that will save you a headache in diagnosing lol

 

i dont know what the sensor in the head does but i can tell you if you ground that wire that in that sensor, your fans WILL come on.
i had an overheating issue when i bought the car, and had never messed with them before.
my dad told me to ground the wire and see if the "sensor" is bad. i dont know what it does, but i know what the wire will do if you ground it.
so if his fans come on, at least he knows the motors are good.
could have hooked 12v to them by now to check them, but might have not thought of that either.
wiring, fuse, relay or sensor. doubt its both motors at once.

 

gonna sound stupid but try turning the heater controls on don't question just try let me know if it works

 

Sorry, but you got this ALL WRONG!

Do not confuse the engine coolant sensor with the sending unit used for the temperature gauge. The engine coolant sensor uses a two-wire connector (usually a black and yellow wire). The sensor is a thermistor (a resistor which varies the value of its voltage output in accordance with temperature changes), as the coolant temperature increases the sensor resistance decreases. A failure in the coolant sensor circuit should either set Code 14 or 15.

1. Cool Fan Switch- is found on Passenger side Head, between plugs 6 and 8. Stock is set to turn Primary fan(passenger side) On at 225* and off at 200*.

2. Engine Coolant Temperature Sensor- is found on the Thermostat housing or on the Intake Manifold. It sends the coolant temperature to the ECM, and is used to turn on secondary fan(A/C fan) when needed. ECM will turn On secondary fan at 238*.

3. Sending Unit- is found on driver side Head, between plugs 1 and 2. Its used for the temperature gauge readings.

Hey cIaRmOaCrZo, I'm not trying to be an A$$hole. But your using a car that's got some really messed up wiring to help others, and its got you running around and guessing too!

 

hmm, that kind of stumps me. i dont see how thats possible. but if you said it does indeed do that, then i cant argue and say your wrong.

 

haha, you dont sound stupid. thats actually a quick test to see if it works. because the when u turn the ac on, the fan should come on. that is one of the three ways the fans can come on period.

 

What you did here was manualy ground the cool fan switch, which manualy turn on the fan.

 

sry, guess i was just ignorant of that sensor lol. i always thought there was two.

 

Short Story: My A/C did not have freon in the system. So even with the A/C turned on, the fans did not come on. But at the proper engine temp they did.

 

well its assuming you have suva or freon in it. of course if the pressure in the line, the compressor wont kick on, there for not complete the circuit for the fans to come on.

 

YES, correct....and it WAS R-12 back in 87.

 

lol. its 2009 right now.

 

I installed a kit like this when i did my 2.8 to 5.7 swap and installed like a 165 thermostat (or something like that) so i went down to local autozone and they carry a kit that i wired to a switch and it has an adjustable relay so u can have the electric fan turn on when ur thermostat opens....It's only like $40. Just a thought!

 

Lets recap here...

RodBuster stopped posting nigh onto 4 weeks ago,
so I wonder if he solved the original problem?

Subsequently, off we go, including the predictable entries
pro/con about manual switches. Obviously, the fan/control
system must be one of the weaker aspects of our third-gens,
since repair questions occur as frequently as politicians lying.

What would it take to put together some wiring diagrams &
component locations, sticky it, and then inquiries can be
answered "See above." The storage savings alone should be
enough to justify some faster servers.

 

OH Boy!!!!! Back in 87, R-12 was the refrigerant of choice! It was the org. R-12 that (LET OUT) out back in 2002. So my fan would not turn on when I seleted A/C On. No freon > No pressure > No Fan....and yes, you are correct, it did not complete the circuit.

***Side Note*** Refilled with the R-13a crap. Fan comes on again, A/C is holding up and blowing cool. Not Ice Cold like R-12 use too! Damn, those were the days.........

 

Update:
I tried like heck to not take the Z to the mechanic but finally caved in.
Turns out one of the fan wires in the bundle that runs across the passenger wheel well had to be replaced.
The Camaro had been running cool for a few weeks now.

Thanks for all the tips, Ray

 

oh

 

how much?

 

$130.00