Another ancient thread question. I found that Oreiley has these in their BWD line, just add "T" to the front, like TFS1. I have a question though, when it says this above:

Is that the range of when it might turn on, or is it on at 238 and off at 222? 238 seems hot to even start cooling. I'm trying to get calibrated on what hot is in a V8 though. My engine currently runs near/under 200 most of the time.

It means that the switch "closes" at 238* to turn on the fan and "opens" at 222* to turn off the fan. That is rather hot but GM wanted the engine that hot to help with the emissions, from what I read. 200* is not that bad. I'm running a 160* thermostat but I'm always hovering around 185* with a hypertech ThermoMaster MemCal.

I installed the TFS1 only to discover that the switch plus pigtail is so long it will hit the header. I butchered the pigtail so it is shorter and goes 90 degrees but it is sort of a hack job. I have to decide whether to go with it or buy something else...

I assume you have double fans. I did a dual fan canversion swap (had a single fan) and completely did without the switch. I did away with the switch because Im running in an extremely hot environment out in the lower section of the Mohave Desert. So when my fans turn on, they both run at the same time. Here is the link to the wiring below if you wanna forget about the switch.

http://www.metzcon.com/racing/dualfans.htm

Deleted diagram because I have a better one

Good schematic. But if you wire as the pictures shows, the fan will be on constantly, this pulling excessive draw from the battery and severely shortening the life of the fan. Granted that the fan is of brand, I'd like to make my items last. Secondly, wiring to and ignition switch source (which is more than likely a fused to the fuse box, can burn up that fuse under the dash, but MOST IMPORTANTLY, you can cause a fire if the wire gauge is not big enough.

I didn't realize the thermostat. But according to the picture, I think that type of setup involves a bulb that must be inserted into the coolant stream. Effective indeed. Good picture.

Thanks,It has worked excellent since its install last year.

I would definitely not go this route for 2 reasons. Sticking that in the core will cause a leak due to wear from the vehicles vibrations and second, a cheap fix can cost a hundred or so to buy a new radiator if a hole is made. Don't due a half doodoo job and cut corners. Just rewire correctly. If you want the fans to turn on sooner, you'll need to invest more money and have Tuned Performance burn you a chip with lower settings.

Its definitely snug without vibration as you suggest , but I will still let you know in a couple of years how its doing.

Oh. I thought those go inbetween. Heck, even better. So that is one good alternative.

When I bought the car it only came with the single fan so I added a extra larger fan as the primary and that's the only way I figured I could wire it to run at the lower temp working with the 180* thermostat and using the stock fan as back up. I'm always open minded to suggestions

Can anyone tell me what kind of connector I need to connect to this?



It looks like threads, but it's just ridges. Must be some kind of push-on connector.

^^

Alligator clip

Wondering where you got these specs from?
I had the parts guy cross refrence the FS4 and came out to be Standard TS82 but I'd like to confirm its temp rating.

Thanks

Good to know. I always had to order a Sorensen from a local parts store.

If I'm not mistaken, that's the upper and lower limits of the tstat - where it turns on and off.

Pretty sure the female side of this. I have the same switch, I tried to put a nut on it like a dodo. Now I have to get one of those bullet connectors.

I like to use the Wells SW505 temp switch-its 212 on/202 off. I've been using variable 3-speed relay harnesses with 2 temp switches for low and medium fan speed then HD relay for AC over ride. Personally, I don't use the ECM for fan operation since I prefer 2-speed OEM fans or HD single speed Mark VIII fans but either way, I have found the best combination is the SW505 for a low temp switch, the SW502 is I believe 230 on/218 off or so and that is my "medium" temp switch since I use AC usage for high speed which bypasses both switches and runs the fan on 100% speed.

Just my .02 anyway.

Are you using resistors for low and medium speeds?

I've been thinking about achieving low speed the way 4th gens do it, by having a relay switch dual fans to run in series, then give both fans full power for high speed.

Yes....I use my own resistor style harness to control the fan speeds....it works on any fan and can be used on dual fan assemblies, too. I prefer using the most powerful fans available which means going with OEM fans so that I can use the full range of cooling capabilities if need be. From my experience some aftermarket fans may work adequately but none can compare to what most automotive manufacturers have designed. Imo, the 3rd gen setups are just outdated and there are much better, modern alternatives.

Can you describe your setup in more detail? It's too late for me for now, but I went into this naively and am just firing off OEM fans from 75 amps relays. I started with my EBL ECM turning on both fans whenever it wanted, but the current draw and initial surge was a problem. I've reverted to the ECM controlling one fan and a coolant switch controlling the other, with the coolant switch being higher temp so it only comes on if things are getting very hot. Currently no provision to turn on both fans with A/C, but the A/C isn't working right now anyway. With both fans at 100% and the headlights on, I can't maintain full voltage at idle (even with 150 amp alternator), so I'm hesitant to make that be normal operation.

Basically, I use a resistor to run the fan(s) at about 6V on low off the LOW temp switch which triggers a relay. Then, the "medium" temp switch triggers a second relay which directs power through a resistor that allows about 9V to the fan(s) and IF high speed is desired, I use a jumper wire between the two relays or just tie in the AC clutch coil-either way it will bypass both relays and trigger a stand alone 70-amp relay for full 100% fan speed with no resistance. Since each progressive speed is stepped up as needed starting with low speed, there's no more inrush spiking currents.

Thanks. I looked briefly at resistors to try and solve inrush, but the fans pull huge current so the resistor would need to absorb huge power. What size and wattage resistor did you pick? Do you have a link or anything to the parts?

formula1le, what relay(s) do you use?

The relays are Tyco 5-pin 40 and 50 amp rated. The 50 amp relays have built in diodes, the 40 amp relays have 100V resistors internally. The resistors are basically various diameters of wound stainless wire....the ones I use work perfect for the Motorcraft fans.

I have a stock 84 camaro z28 5.0 ho with stock fan with a 180 thermostat replaced the electric fan switch with one from autozone, and my car still over heats, my fans seem to not be working properly they wont turn on unless i spin the electric fan then it will stay on the. Turn back off after a while, what do you suggest i do??

If they start when you give them a boost, sounds like the motors have an issue. I'm no expert but you probably need to replace the fans (or motors if they can be had separately). You could run +12 directly to the fan connectors and see if things are any different. If not, you know the fans are done.

Here's a reputable company that has exhalent fan systems .=

http://painlessperformance.com/


I thought I would post the three adjustable fan controller diagrams I have as final drafts.
I've learned a lot over the last year and have changed to circuits that I believe are now a huge improvement and best yet are safe.
(By the way that first diagram is what came with the controller kit. Do not pay any attention to it in yours.)

This is the controller used in all three = You may need to enter the part number into the sites search bar = # 733653

http://www.autozone.com/autozone/par...67187_69565_0_

The first one is the simplest, using the circuit controlled by the switch in the head and using the single stock fan or one similar to it.



Second one is a completely independent circuit from any stock wiring.
It is for a single basic fan that can be run on a rating of a 30 or 40 amp relay.



Third one is also completely independent and for a single high amp fan.
A 130 amp alternator may be necessary for the fan.


There is a simple method of setting the fan on temp.

I just recieved my relay set from Formula1LE and it's fantastic. I'm not sure where I'm going to mount the resistor piece yet, but the rest of it appears very well made.

I'm not really understanding this system. My factory service manual shows (for my VIN 8) that the fan is controlled by the ECM. I have two fans. At least one of them is controlled by a switch on the side of the block. In my manual, it's only for VIN H cars that this system is listed. I haven't even traced my wires for the other fan to see how it is controlled.

I bought the FS111 (right) to replace my stock cooling fan switch. But it does not match with my stock (left) cooling fan switch.

Am I missing something? Is this the wrong part? I have a 1992 Camaro RS 305 TBI.

Thanks

You are showing us a knock sensor on the left, that isn’t your fan switch.. They have a similar connector but are completely different. The fan switch will be in the cylinder head; that knock sensor came from right above the oil pan in the engine block..

I have a V6 RS 1992 and I got the same problem. Fan turns on only with AC. How did you solve the problem?
I unplug the sensor on my intake manifold and fan in on all the time, service soon light is on, but my temp is working too!
What is going on?

On the V6 cars, the fan is actuated by the ECM based on the temperature sensor (I believe the one that you are showing on the intake manifold) input. I think the gauge is still driven by a separate temperature sender. Take a look at the attached PDF (sorry for the crude picture). There is a way to test the ECM's ability to actuate the fan through one of the lines on the ALDL connector. Given that the A/C causes the fan to come on (indicating that the ECM is able to actuate it), I'd be looking at replacing the temperature sensor (or at least measuring its output signal (0-5Vdc) at both the sensor and at the input pin to the ECM. Hope this helps.

The V6 are just like the V8s, they've got the exact same temp sender for the dash gauge, it just threads into the "corner" of one of the heads.



The one in the top of the lower intake is the ECM coolant temp sensor.

Thanks for the reply.
In passengers site head there is a temp sender to my dash board with 1 pin.
In my intake manifold there is that 2 pin temp sender to my ECM.
I conclude that cause when I unplug it Radiator fan is on all the time and the ECM dont know my cars temp (not working good when its cold).
So I think I need to change the 2 pin sender from intake manifond and not the 1 pin from the head!
I ask cause I live in Greece and parts are not so easy to find.

Thank you all for your time

Alright y’all...hit pretty much every thread here...GREAT info. I have a ‘91 Z28 305 TPI dual fans, just replaced radiator (Summit stock replacement aluminum 2core) and she overheated viciously on way home, secondary fan is not kicking on at all...(AC still in place but not serviced) ordering new fan switch, temp sensor, and relay from RockAuto (last two only since making the order). 2 questions: 1) should I forego the stock replacement fan switch in favor for a lowered temp, engine is completely stock but I do have a Hypertech prom not installed currently. 2) and only cause I never paid attention to the stock fans and now using an after market set that came with radiator, but are our fans “pushers” or “pullers”? Thanks in advance.

Since they are behind the radiator they need to be PULLING air. If they're not there's your problem
And what is holding your radiator in place? You need more than radiator hoses holding it

Just wanted to verify pusher vs puller, they are both wired as “pullers”. However the secondary isn’t energizing. She got well over heated “tap dancing on the red”.
These pics were taken before, driving, test fit of intake making sure radiator was sitting low enough. I have a couple of straps holding the radiator now while I am fabbing up an aluminum sheet metal shroud. The stock shroud just wasn’t gonna work, tried my damndest to maintain the stock look but after several mods and trimming gave up.

Is their two fan relays? I found one for primary on left side firewall near master cylinder. Can anyone point me to location of the secondary fan relay? I think it’s located same location as primary but need to verify. Being in Tokyo and ordering online need to make sure so as to get everything at once. THANKS

if i'm not mistaken the 2nd fan relay should be pass side near your radiator /battery

I got a switch for my single fan (from a '84) from Painless that's 195 on/185 off.

Check these out:

https://www.ebay.com/itm/ELECTRIC-EN...53.m1438.l2649

You can select the desired temperature range for fan operation. Decent price too. Just have to change the connector on your wiring harness that is most likely brittle and broken. I put one in one of my cars for a "trial run". So far it has been working perfectly. 3/8NPT is the size needed.