Shane4524

Alright I have a '86 Camaro IROC-Z. For some reason the fan would wait until 240-250 degrees to turn on. I am not sure the exact temp because the gauge in the car wouldn't always work, but I ended up replacing the coolant temp sensor and now the gauge in my car works but the fan won't turn on at all...

Please give me suggestions... Like detailed explanation on how to check thermostat and stuff or maybe just putting in a toggle switch for the fan. Anything will be appreciated! Thanks!!

stahrman0612

You can do what I did. I wired my fan to come on whenever I want by a toggle switch under the dash. I tried to replace the temp sensor with a lower fan turn on, but couldn't get the old one out and damaged it. So now the only time my fan will work is when I manually turn it on. Great control, but the down side is if your mind is on something else you could forget to turn on the fan and that can mean TROUBLE!!!

SiCkRs

iTrader: (6)

That is exactly what they did to mine too but also theirs times that i forget to turn it off and the car uncharges.

henryd3

iTrader: (128)

These fan systems are notorious for malfunctioning Go look here in the electrical section and read the article that pertains to your fan system .https://www.thirdgen.org/technical-articles Also check older posts in this cooling section. You will soon see that you're not alone, lots of good solutions here. Good luck

stahrman0612

What do you mean by "uncharges" ???

RyanEricW

probably meant undercharges.

henryd3

iTrader: (128)

?

Shane4524

Can someone give me a good explanation on how to set up the toggle switch and like details on what kind of things i will need.

Also can someone tell me where the cooling fan temp sensor is located on the motor?

henryd3

iTrader: (128)

The fan switch is in the passenger side head between the#6 and#8 plug. There should be a connector attached to it with a green with white striped wire. The connector snaps over the kind of roundish end of the switch. If your fan goes on when the key is on and either you ground this wire from the connector or turn your AC switch to on, then your fan relay is good. Best to leave the relay in play for your protection. Over by the brake booster on the driver side there are two identical relays. One has leading to it a thick red wire, a thick black with red stripe wire, and two skinny wires. One is the green with white stripe wire from the fan switch and the other is brown or something like that. You want to wire a switch to tap into that green with white stripe wire and provide a ground to it. That way any time the key is on and you throw the switch the fan is on.

henryd3

iTrader: (128)

OOPS, hope I wasn't too hasty. I was assuming you have the single fan setup and not the dual. Was I correct?

Shane4524

Yes it is a one fan setup. Thanks so much!!! So this eliminates having to worry about somehow accidentally leaving the fan on?

henryd3

iTrader: (128)

Yep, it will go off when the key is off. The only slightly tricky part is deciding when you want it on. Also as long as the fan relay works, by replacing the fan switch with one that turns it on when you want it to you can either let it work normally or use your switch as a backup. Have fun

Shane4524

I am going to be very complicated now, can you reword how I am going to hook up the toggle switch one more time? Maybe be more specific please, unless that's as specific you can get, but I won't be in the car till the morning so I haven't even looked yet. But just explain again how the toggle switch will hook up? Details please! Thanks so much!!!

henryd3

iTrader: (128)

I don't know much about simple electronic stuff, like if you need a SPDT switch or what. Ask at Radio Shack or Lowes or something for a simple switch to close or complete a curcuit. Connect a wire somewhere near the relay to that green with white stripe wire
( ask for a connector to do that) and run it to the interior wherever you want to locate the switch. connect the wire to one side of switch. Connect another wire to the other side of the switch and secure it to a good solid ground . Now when you throw the switch the wire is grounded, and when you switch it the other way its not grounded. Before you do that check to see if removing the connector from the fan switch and grounding the wire with the key on turns on the fan. And if key on and AC on turns it on. Then this will work

Dartht33bagger

You could always just wire the fans to the prong on the sensor that has the ignition current. That way it will work like an old motor so whenever the car is running the fan will always be on.

NINÅ

henryd3

iTrader: (128)

Yep, Diagrams are good and not nearly so wordy and confusing. Good job NINA, you're one of those electrical genius guru types that makes TGO such an amazing source for knowledge to keep us movin on down the road.Wow

pbtrilogy

Im also having the same problem as the op.

I posted some pics of what im looking at, but not sure what they are.

The 1st pic is a relay right next to the fuel relay...is this the fan relay?

The 2nd pic (sorry for the blurryness and bad quality, but it was hard to get) is in between the # 6 and 8 plug...is this where the fan switch should be?
Right now it just looks like a bolt with nothing attached to it

-Thanks

NINÅ

Quote:

Im also having the same problem as the op.

Zepher

iTrader: (1)

You should only have a temp sensor on the TPI lower manifold and that sends the temp to the ECM which then controls the fan (drivers side fan if you have dual fans). The sensor in the pass side head is used on dual fan cars for the Secondary Fan and I believe on the earlier carbed motors like the LG4 and L69 to control the main single fan.

pbtrilogy

Is this the sensor you are talking about?

The 1st pic is from the passenger side.
The second pic is my attempt at trying to get a closer pic of it.
There is a thin black wire that is connected to it that runs past the throttle body and is cut and doesnt go anywhere.

jeff_blake

iTrader: (1)

that looks more the the egr temp sensor, which is discontinued now days. assume check engine light is on at well?

87350IROC

iTrader: (2)

It is painful to get the stock systems to work at the temperature you want. I eventually got fed up and now control my dual fans with a Dakota Digital controller, PAC-2000. It works really well and allows me to set the exact turn on and turn off temperatures for each fan independently. Highly recommended.

Gunnar1

Thanks 87350IROC. I only saw your post today but it is a great idea. I may do the same.

rusty vango

really ,its best to just repair it CORRECTLY!!!!! no silly flip switches no crazy rewiring of the circuit DO IT RIGHT!!!

Blue_Thunder

iTrader: (1)

Can you post a picture of that sensor on the lower manifold? I have an 86 as well, and I am changing the thermostat and need the fan to turn on at a different temp. All summit shows is that sensor in the side of the pass side head that is not used on the 86 model.

Lucid

iTrader: (4)

If its an 86 TPI motor with the single fan, the temperature sensor located on the front of the engine (lower intake manifold) sends the temp to the ECM and the ECM grounds the Dark Green wire with a white stripe on the radiator fan relay on the passenger side of the radiator.

To change the temperature that the ECM commands it to come on, you can burn your own chips and dinker with the fan on and off temperatures.

Coolant temperature sensor (BLUE):


The temperature sensor used in 86 that goes into the passenger side by the head is for the carb cars. Instead of the ECM grounding the green wire, the fan switch grounds the green wire on the relay and energizes the fan.

The only real way to make it come on sooner is to burn a custom chip, ground the wire manually with a switch or to install an adjustable thermostat with a probe of some sort that goes into the radiator fins.

I used to run the adjustable thermostat (from Oreillys) but I had problems with the relays dying out or sticking. I learned to burn my own chips and reused the factory relay for good.

RyanEricW

You should fix the car correctly, not bypass it with a toggle switch.

Peter M

Hey folks New member here so hello to all, If its alright Id like to re open this thread. I have read a crap load of threads on this topic and this one has the most replies so maybe Ill get more from here.
I have a 95 camaro 5.7 and I am also having the same problems with my fan not turning on... I see a couple people here have said "just do it right" as I wish to do. Im not fiddling around re wiring a new switch or modifying anything to achieve the solution other than the proper solution.
I have installed a new rad (bled properly) new temp sensor, new water pump and thermostat & cap.
The fan works when AC is on and I have checked all my relays (including AC)
Does anyone know the proper fix as those above mentioned but not elaborated on?
Thanx in advance for any advice

MSRed91Camaro

iTrader: (2)

Good info

stahrman0612

I have been using the fan switch for 8 years now and love it!! Unfortunately I can't fix it correctly because my temp. coolant switch will not come out and is damaged!! I can control precisely when I want it to come on and keep my temp. where I want it. Here is a pic of the wiring and where I mounted switch.

MSRed91Camaro

iTrader: (2)

Cool can tou explain which wire is what? and I like the placement of the switch.

stahrman0612

"Cool can you explain which wire is what? and I like the placement of the switch"......thanks. The wire on the right (with blue male/female connector) that looks like it's going to the relay on the right is actually not hooked up to anything. Not sure why I did that...lol. The green wire from the white/black relay is the wire for the fan turn on. That is going to the acc. on the switch inside the car. The ground wire on the bolt of the relay is going to the ground on the switch. With this set-up, the fan will not kick on with your A/C, you will have to turn it on manually. I have a hypertech temp. coolant switch that is brand new that kicks the fan on at 185. If anyone is interested........make an offer!!!

MSRed91Camaro

iTrader: (2)

what if I dont have AC
"this is my post from another thread but stiill aplies" My car recently had a 383 installed in it and I swithed over to a carb set up, the mechanic who installed m engine set up the fan to run whenever the key is turned on. I do not know exactly what he did to do this but from what I can tell he has the fan rewired to a what I think is one hot or power wire with a fuse and what I assume is a ground wire. I do not know where these are hooked up into the interior of the car but I can follow the two wires from the fan to a fuse to the fire wall. I want to add a toggle swith so could I tap into the power wire behind the fuse an run it to a toggle switch, then run the other terminal to another ground, thus when I turn the switch on it will allow the fan to work and then when I turn it off it grounds it so it turns off. Does this sound right/ will it work....is it safe... or is there something else I should do? thanks for the help."

Would this work or would the above method used by stahram0612 work?

stahrman0612

Not having A/C won't effect anything. I was just letting you know if you do have it, you'd have to turn fan on manually. Sounds like he wired it straight off the fan to a switched power source in the fuse box. Just find that fuse, and put a switch on it. Or delete what he did, and wire it up like I did. Either way will work.

ronnied60

so is it one wire from the fan to the sensor and the other wire to grond

stahrman0612

The fan sensor wire going to a on/off switch.....that's it. (I know .....this thread is old...lol.)

JamesG1986

Hello I just bought my first car, it's a 1986 camaro 305 with a 4 barrel carb on it. It a base model, nothing special. It overheats and the cooling fan won't come on I don't want to jerry rig it in any way, I just want to change the sensor that could possibly be bad. I changed the fan blower relay by the brake booster and I also changed a sensor on the passenger head near the oil dipstick it is connected to a green wire and it still won't come on, the fan works if I turn the A/C on, I let it heat up to about 220 then I kick it on but it won't come on automatically if I jump out the A/C fan relay it will kick on. I see another sensor on the drivers side head I'm not sure what it's for or what it does, I'm stuck and don't know what else to changed. Please help me I'm open to any suggestions. Thank you.

RamIt

The drivers head sensor is for the gauge.
If you jump the wire to ground on the passenger side fan switch and the fan doesn't come on, you have a break in the wire some where in the harness. You could route a new wire from the sensor to the relay.
The fan switch may be set to come on after 220* if the fan operates when the wire is grounded out.
The switch may not switch till 238* on your application.

JamesG1986

Ok I just pulled the wire off the sensor on the passenger side head near the oil dipstick,I then took a copper wire jammed it in to the connector and touched the copper wire to the fender, I turned the key on and nothing happened, what does this mean, I just changed that sensor and I also changed a relay by the brake booster and my fan still doesn't kick on, I have to turn the A/C on to get to kick on, I just want to get this fan running correctly by itself, please help me I'm open to any response and I don't want to jerry rig anything

gbizier

Just wanted to post this to help others out in the future. I'd also like to ad a preemptive thanks for the great info in the thread. It really helped point me in the right direction.

My scenario was fan worked with AC (relay/wiring/motor check good), but got nothing when shorting the sensor connector to GND.

I ended up having a direct short from the sensor connector wire (green) to ground. This is easily tested by checking continuity to GND. More than likely the wire either got pinched or melted.

Solution:I cut the shorted section of wire out between the relay and sensor connector and soldered a new piece of 20-gauge wire in place. This was a correct enough fix for me without having to dig into the harness. Just be sure to leave enough wire to couple with and use shrink. I also suggest silicone insulted wire.

With the short to GND, you would think that the fan would continuously run (similar to test condition). That was not the case. After replacing the shorted section of wire, it worked (fan kicked on @ ~220) and tested properly (I was able to get the fan to spin with key on and shorting the sensor connector to GND).

rushtk

what is the temp of the engine for the dual fans to come on? We just replaced sensor and relay, let motor get to 220 and no fans. Going to do a hardwire to fans and see if they kick on. Anyone know where to buy new fans?

rushtk

fans are good and when you hook a hot wire to them they come on. Fuses are good even the one by the battery. All fan relays are replaced, fan switch on motor passenger side is new also. Will check for ground next. may have to run new wire to it all, want my stock system to work.

mantaguy

iTrader: (5)

235* for the primary fan to engage, no info on the secondary.

LiveIt!

I know this thread is old as **** but I just want to say a HUGE thank you for this thread and especially the posts by @NINÅ and Stahrman!! My car has been overheating this week, Monday I drove to school and WAY overheated, Tuesday I drove with the fans hooked straight to the battery (PO hackjob but worked), Tomorrow im so happy I can drive safer with the fans bypassed ON way safer

For any future third genners- on my 1988 Camaro for example, the relay you want is the roundish one by the square relays by the driver side fender. It has 4 wires, black/red, green/white, brown/white and red. You just need to Ground the green/white wire and your fan will turn on and off via key you can splice right in or I just ran a wire into the pushpin connector and ran it to the ground bolt to the right

Again many thanks!!!!!

rushtk

could you show pics?

LiveIt!

Sure can! Like I said I just have a wire running from the green/white and then an alligator clippy clipping it to ground, ik it's a hackjob but at least I didn't hack my wiring harness

allenrep2000

I found a bad wire coming off of a terminal block located next to the battery. It goes into an inline fuse, about 3 inches of wire to the inline fuse. I just cut it out and replaced it. It supplies power from the battery to the fan

allenrep2000

The brown wire from the terminal block to the white inline fuse supplies power for the cooling fan. I found it completely disintegrated

LiveIt!

nice work