Flex-a-lite fan

[Ogre]

I've got another problem I am hoping someone else here already has the answer.

I have a Flex-A-Lite 175 electric fan I am installing in my '67 Mustang coupe. I have it wired up according to the directions, minus the steps for cars with air conditioning. Started up the car and got it nice and hot, but the fan never came on.

Does anyone else here run one of these fans and could tell me what I might be doing wrong.

I went to the company's web site, but that was no help. I did get the fan to turn on by running a wire from the "M" terminal straight to the battery. Here is my how I have it set up:

"+" terminal is going to the starter solenoid

"G" is run to a ground on the radiator support

"M" is not hooked up right now, but is for a manual switch

"C" is not used because it is for A/C stuff

"B" is run to the positive side of the battery

The capillary tube is pushed through the radiator core near the bottom/outlet

Any help will be greatly apprectiated. Thanks.

 

[D.Hearne]

Move the heat sensor to the top right side of the radiator. That's where it gets hot first. You've got it on the cold side of the radiator. And first chance you get, order a Painless Wiring fan sensor switch kit to replace what you've got. I used that same setup on my V8 Ranger and it only turned the fans on about half the time. The Painless Wiring kit works EVERY time.

 

[Ogre]

I was thinking that either the thermostat for the fan wasn't working or I have it in a bad place. I will try what you said and see if it works.

 

[70dvr]

I've had a similar Black magic fan for the last 40,000 miles and it's worked great. I mounted mine upside down to hide the wires and thermostat knob. I think it would be a pain to set one up without a real temperature gauge. If you don't have one you could install one temporarily.

 

[Tim65GT]

"+" terminal is going to the starter solenoid

"G" is run to a ground on the radiator support

"M" is not hooked up right now, but is for a manual switch

"C" is not used because it is for A/C stuff

"B" is run to the positive side of the battery

Where is the "+" hooked to on the starter solenoid?

 

[12sec67]

the solenoid is not a good source of ignition positive (switch on)

 

[mikethebike]

I've been using a Flex-A-Lite SS mechanical fan for more than 20 years with zero problems. Just 1 more reason I like to KISS.

 

[Ogre]

I will try more things on Friday. I got an email from flex-a-lite telling some more things to try.

I will post again with updates.

Thanks for all the help/posts so far.

 

[Ogre]

Good news! I worked on the fan issue last night and got it all fixed.

I turned the whole fan unit around so the capillary tube was close to where the inlet is and the coolant comes in from the thermostat housing.

I also took the wire from the "+" terminal that I ran to the starter solenoid and ran it to the fuse box under the dash.

Works like a champ now! I even had to adjust the thermostat setting on the fan unit to let the coolant get a little hotter. We'll see how it works when it gets hot around here.

Thanks to all who posted and gave me advice to what to do.

By the way, I don't know if it just me, but the car seams like it has more power. I expected a difference, but it is more than what I thought.

 

[66 Restomod]

I've been using a Flex-A-Lite SS mechanical fan for more than 20 years with zero problems. Just 1 more reason I like to KISS.

Mechanical fans often work fine, but can be extremely dangerous and use too much hp.

 

[Edbert]

As far as the sensor is concerned, if you have one of those that wedge in between the fins of the radiator...throw it away. Even if they work when new they'll fail to work well over time. They'll get loose or get dirty or corrode and make a bad (thermo) connection eventually.

I got one that threads into the coolant jacket of the manifold, don't remember the part number but it was off a Taurus 1988-92 I think. Brass fitting, sealed wires, hooked right up and activates at 160-170 degrees.

Edit: I found a picture with it visible, not a great one but you can get the feeling of what I tried to describe...

 

[Ogre]

Where would the sensor connect to on the electric fan unit? I will probably want to switch to a sensor this summer when I catch up on a few other things.

 

[D.Hearne]

Sensor wire goes to a relay switch, that switch supplies power to the fan. Or at least that's how the Painless Wiring kit works. This sensor has a single thin wire to the relay.

 

[Edbert]

Yup, and the second wire is a ground. These sensor are little more than an automatic on/off switch.

 

[Ogre]

Thanks. I will have to look into that. Like I said, I will probably go to that this summer when it's warmer out and I catch up on a few other things I need to do, like welding on new rear quarter panels. Yikes!

 

[mikethebike]

Mechanical fans often work fine, but can be extremely dangerous and use too much hp.

Let's see, I've been doing this for 45 years and never had a problem with a mechanical fan. And I'd be willing to bet on a street car you will never see the h/p difference. And if you are THAT good at racing I should have heard of you by now.

 

[66 Restomod]

Let's see, I've been doing this for 45 years and never had a problem with a mechanical fan. And I'd be willing to bet on a street car you will never see the h/p difference. And if you are THAT good at racing I should have heard of you by now.

"I refuse to use a flex fan because of a catastrophic accident I saw a few years ago . A friend was leaning over the front of the car and revved the engine he a blade came off the fan . The blade hit his neck and he bled to death before we could get any help . For those of you that choose to run a flex fan PLEASE be careful!"
http://www.v8buick.com/showthread.php?t=131658

"Flex Fan Accident Brings Mechanic $4.6 million Settlement"
http://www.paulbeltz.com/cases/details.cfm?ID=43

"Potential Hazards of Automotive Flex-Fans"
http://www2.worksafebc.com/i/posters/2002/wsflexfans.htm

"My first truck was a 82 F150 stepside with a 351W in it. After making some upgrades to the engine via Mr. Edelbrock I put in a flex fan. It seemed to work okay, but one day while I was tightning some belts the bolt I was on rounded out and my hand went slaming into the flex fan. I got some real nasty cuts on my hand. The blade actualy first hit me on my knuckle, it cut me down into the joint. That hurt. Bad. I was able to see my bones when I moved that particular joint. Now the scar tissue has built up inside that joint and I cant open or close it all the way. I also lost some feeling in the tip of my finger (left pointer finger, joint closest to finger nail). I'll never use one of those again."
http://www.ford-trucks.com/forums/314813-flex-fan-vs-electic.html

...and on and on. That's not to say all mechanical fans will fail, but I said they can be extremely dangerous.

Concerning power gains going to electric, taken from the Flex-a-Lite website (they sell mechanical flex fans too):

[full-size truck dual fan] "Up to 17 additional horsepower -dyno proven- is transferred to the wheels by removing the belt driven fan and fan clutch. Decreased load on the engine results in improved fuel economy - up to 2-3 mpg."

A small block Ford with a mechanical fan would see less power gain for sure. I'd think about the same as a crank underdrive pulley or a set of good mufflers. I switched to electric just recently mainly for safety. (I haven't been to a drag strip in 15 years.)

 

[mikethebike]

"I refuse to use a flex fan because of a catastrophic accident I saw a few years ago . A friend was leaning over the front of the car and revved the engine he a blade came off the fan . The blade hit his neck and he bled to death before we could get any help . For those of you that choose to run a flex fan PLEASE be careful!"
http://www.v8buick.com/showthread.php?t=131658

"Flex Fan Accident Brings Mechanic $4.6 million Settlement"
http://www.paulbeltz.com/cases/details.cfm?ID=43

"Potential Hazards of Automotive Flex-Fans"
http://www2.worksafebc.com/i/posters/2002/wsflexfans.htm

"My first truck was a 82 F150 stepside with a 351W in it. After making some upgrades to the engine via Mr. Edelbrock I put in a flex fan. It seemed to work okay, but one day while I was tightning some belts the bolt I was on rounded out and my hand went slaming into the flex fan. I got some real nasty cuts on my hand. The blade actualy first hit me on my knuckle, it cut me down into the joint. That hurt. Bad. I was able to see my bones when I moved that particular joint. Now the scar tissue has built up inside that joint and I cant open or close it all the way. I also lost some feeling in the tip of my finger (left pointer finger, joint closest to finger nail). I'll never use one of those again."
http://www.ford-trucks.com/forums/314813-flex-fan-vs-electic.html

...and on and on. That's not to say all mechanical fans will fail, but I said they can be extremely dangerous.

Concerning power gains going to electric, taken from the Flex-a-Lite website (they sell mechanical flex fans too):

[full-size truck dual fan] "Up to 17 additional horsepower -dyno proven- is transferred to the wheels by removing the belt driven fan and fan clutch. Decreased load on the engine results in improved fuel economy - up to 2-3 mpg."

A small block Ford with a mechanical fan would see less power gain for sure. I'd think about the same as a crank underdrive pulley or a set of good mufflers. I switched to electric just recently mainly for safety. (I haven't been to a drag strip in 15 years.)

I have some reservations concerning ANY single item that claims a 17 hp and 2-3 mpg increase that comes from the company that makes the product. I've had a Flex-A-Lite S/S fan on the 65 since 1983. NO problems and since it weighs next to nothing and flattens out at speed I doubt the electric units will show a usable improvement. My belief is that electrics are what they make the most money on so that is what they push to the buyer.
Now, having said that I would NEVER run or advise anyone to use a fiberglass fan like the ones that were popular back in the early 70's. I have seen those fail but I have never, and I repeat NEVER seen a steel fan fail in the manor you described.

To address the genius who runded a bolt and cut his finger to the bone.....exactly what kind of wrench was he using? Bet it didn't say Snap-On on the handle. Either that or he used it improperly.

 

[Great68]

I have seen those fail but I have never, and I repeat NEVER seen a steel fan fail in the manor you described.
.

Just because you have never seen it, doesn't mean it didn't happen.

It has obviously been documented as happening before.

 

[Edbert]

When was the last time Detroit (or Tokyo or Stuttgart for that matter) put mechanical fans on their cars? I don't claim to know but I'd bet it was ~25 years ago.

Initially I'd guess it was because of a cost savings via using electric, but now I'm willing to bet it has more to do with liability that anything else. Most corporate decisions come down to a lawyer somewhere in the process.