Fan Wiring: Easy Right? Please HELP!!

I feel like a ***** right now. I spent the past hour and a half trying to figure out why this doesn't work:

I purchased a Cooling Components fan (part number CCI-1770) this morning. After bringing it home I realized that the instructions call out a 70 Amp Relay!! I've never heard of that size being used (used to 35A SPST) for a fan but instead of just using the 35 Amp I wanted to make sure at least 70 Amps could be used.

Well, I can't find a relay anywhere and even if I did, I can't find a 70 Amp fuse. So, the idea came along to use a 100 Amp Solenoid and a 100 Amp Circuit Breaker. Should work, right?

Wrong. At least with the way I wired it. I can byp*** the solenoid and the fan kicks on. But I cannot get the solenoid to work with my switch and have no way of knowing if it is bad.

This is the way it is wired:

100A Alternator --------> Bat of 100A Circuit Breaker
Aux of 100A Circuit Breaker ---------> 1 of 2 Large Posts on Solenoid
2 of 2 Large Posts on Solenoid ------> Positive of Fan
GND of Fan --------> GND
20A Fused 12V Source from Fuse Panel --------> 1 of 2 Small Posts on Solenoid
2 of 2 Small Posts on Solenoid ---------> 12V Illuminated Rocker Switch Source
12V Illuminated Rocker Switch GND ------->

Please also see attached picture.

I can even byp*** the solenoid using the 20A Fused 12V Source from Fuse Panel and the fan goes on (when the Ignition ACC is on). What am I doing wrong? Please help, this is very frustrating and I have spent most of the day/night getting the fan to fit and installing the wiring components.

Appreciate any advice. Thank you!

 

I think you should have the 12v from the fuse panel going to the switch, then the other side of the switch going to the "S" terminal on the solenoid. Leave the "I" terminal on the solenoid empty.

The "I" terminal is for providing a full 12v temporarily to the coil for easier starting.

Leave the bigger wires like you have them.

 

Wow man my apologies if I'm wrong but I think you are way off base here.

First off study everything you can at MADelectrical.com They'll show you how to wire a relay and how to wire a solenoid and everything else.

I don't think it's possible to get your setup to work, as there's no switched power there.

You really need a relay for this, and a 35amp should be fine until you can get your hands on a 70 amp. Waytek or terminal supply co or here. They should be no more than 2 or 3 bucks each.

Why dya wanna use a switch? I think it's a recipe for disaster personally. Who's gonna notice that until your car is hot? The best idea is to use a sensor that will fire the relay at a preset temperature here from perma-cool. I used it and I've talked to the owner, the guy is a genius, literally, and all the parts are superior. With his kit you don't strictly need a relay, but I used one because I'm just more comfortable with it and I wanted the high speed fan to fire when the A/C was on.

Anyway here's how I wired up my low speed fan, I think this may work fine for you and its cheap and easy.

I used a 70 amp relay(your 30 is probably fine but 70 is better for longevity ) and wired it a hot wire from where the Batt connects to the solenoid, then the opposite terminal on the relay to the elec fan, and as the trigger I used the IGN terminal on the ignition switch. It might be called coil as well.

So there you have it. Start the car and your fan goes on. If you want to listen to the radio and turn the key to ACC you don't turn on the electric fan.

Id use at least 14 ga high qualtiy wire like GXL or something, no autozone primary wire.

If your heart is set on the switch, just be sure to use a relay so your switch has a long and happy life Regardless I'd make sure the switch is only hot when the car is running(either acc or ign on your ignition switch-if you're using a relay you're not pulling any amps at all so it won't overload anything)

hope this makes some kind of sense. Good luck, you can do it!

 

Thanks for the help guys. I was trying to make it work with what I have since the solenoid and breaker weren't cheap. The Painless Wiring temp sensor kit was $160 locally and I thought that was way too much.

I'll try the switch still but does this really mean it won't work with the solenoid and breaker? I've tried every combination except the 12V source coming from the switch. But wouldn't the 12V source start the fan the way it's wired now?

I'll also read up Mad Electrical. Please keep the advice coming and thanks!!

 

Your local parts store should have a relay/fan switch combo unit, they are around 40 bucks and are fully adjustable and use a bosch style relay.

Autozone #733647



I have used these a bunch of times and never had a failure. It will also control 2 fans, if you have air.

Using a starter relay is not advisable, those are not designed to be left on for long periods.

 

if you still need a 70 amp fuse, check with the booming stereo shops, they deal with big power.

 

Do those fans really need that much? 70 amps? The whole lighting circuit only runs on a 10 amp fuse.

Why can't you just wire up a 10 amp fuse/line to a relay with a switch? Relays are about $6-8...

 

Here's my understanding, i'm no expert so take this for what it's worth.

I'm running my fan off a 70 amp relay with a 30 amp fuse in the power circuit. It'll blow a 20 amp fuse pronto(what my wiring kit came with) As I understand the problem is with the initial power surge for a fraction of a second when the fan first turns on. For that tiny amount of time the fan draws way more than 30 amps and eventually it'll kill your relay and/or fuse. That's why MAD electrical prefers to run the hot side of the solenoid with a fuseable linik to B+ rather than a fuse, as the fuseable link will take that abuse forever without problem.

That's the theory as I understand it, whatever you read at MAD explains it better and more accurately I'm sure.

What I can say is that when I powered up my wiring harness for the first time (last night) the relay for the fan liked a 30 amp fuse

Oh, NOW I get it , so your solenoid is *ONLY* for the electric fan? Dude that's for a high current application like, uh, your starter. I have no idea how long that would live and don't care and neither should you because its stupid. Spend $2 on a relay you *****.

Then write a tech piece on how you installed your fan and give something back

EDIT: Are you really a Mechanical Engineer? You sound like you're a teenager. I just re-read what you're doing. This is a terrible idea. I was going to explain how to make the solenoid work but instead you should just bang your head against the electric fan until its broken into a million pieces problem solved. Then keep reading the mad electrical site till you understand what's going on instead of going off half ****ed. Read a book, for god's sake, mr. ME.

What's up with people claiming they're 'pro custom car builders' and mechanical engineers and ****?!? Why can't you keep it real?!? I'm just a hack, I prefer to keep expectations low ;-)

 

For what it is worth I'm running a cooling components fan with the kit from painless wiring which uses a 40 amp relay and a 30 amp circuit breaker for the fan and it has worked fine for the past 4 years. The only thing you should use is a circuit breaker instead of a fuse to avoid a open fuse at fan startup (The kit came with a 30 amp breaker. Cooling components sells the breaker and maxi fuse for a 70 amp if you really want 70 amp protection for 59 dollars.

 

Hmmmm......

we use 75 amp relays at work on a daily basis. (we build aerial trucks for the power companies) Never thought to look at who makes 'em. I think they might be Cole-Hersey relays.

Anything over 75 amps and we use continuous duty Cole-Hersey solenoids. They look like an old FoMoCo starter solenoid bit w/o the notations (stampings) for "I" and "S" on the case.

 

[/quote]
EDIT: Are you really a Mechanical Engineer? You sound like you're a teenager. I just re-read what you're doing. This is a terrible idea. I was going to explain how to make the solenoid work but instead you should just bang your head against the electric fan until its broken into a million pieces problem solved. Then keep reading the mad electrical site till you understand what's going on instead of going off half ****ed. Read a book, for god's sake, mr. ME.

What's up with people claiming they're 'pro custom car builders' and mechanical engineers and ****?!? Why can't you keep it real?!? I'm just a hack, I prefer to keep expectations low ;-)[/quote]

Wow, you have issues buddy! Nice response you douche. I am an ME and an Engineering Manager. I never made the claim to be a pro custom builder and if you know as much as you say you would know that Solenoids fall in the gray area of electromechanical engineering not strictly mechanical.

You ever heard of the saying: don't have something nice to say, then don't? Better yet, man up and say it to my face next show you see me at. I see you are in LA so that shouldn't be too hard to do.

Internet courage, just a mouse click away...

 

wow johnny1290, your'e either a jack*** or think you are funny.. Either way you aren't any help to anyone here.

It is possible to do what he is trying to do with what he's got, yeah it may not be the best way or the best part, but it is possible.

One problem is that the solenoid is not really intended to be held on for long periods of time.

Did you try wiring it up like I suggested? I don't have the parts in front of me to try it, but I am pretty sure it will work that way.

from what you've written I ***ume now you have

connected to the "I" terminal. Which is an output of 12v when the solenoid is ENGAGED.

this one I ***ume

is attached to "S" terminal. S terminal expects to see 12v to engage the solenoid, but instead you have the other end of the switch going to ground. Flipping the switch will do nothing on the solenoid. No power will come from "I" because the solenoid is not being engaged. No power will through the large cables cause the solenoid is not being engaged.

 

Update on the issue. Thank you for all your help everyone there was some great advice -1. Maybe this well help someone in the future:

The solenoid that was used was a Cole Hersee and the issue was that it was a 100A Intermittent Solenoid (10 seconds on, 20 minutes off) after checking the specs on their website. An auto electric shop sold it to me with the breaker when discussing the design. I hope they'll take it back. Probably not.

I picked up an 85A Continuous Solenoid and wired it as follows:

100A Alternator --------> Bat of 100A Circuit Breaker
Aux of 100A Circuit Breaker ---------> 1 of 2 Large Posts on Solenoid
2 of 2 Large Posts on Solenoid ------> Positive of Fan
GND of Fan --------> GND
20A Fused 12V Source from Fuse Panel --------> 12V Illuminated Rocker Switch Source
12V Illuminated Rocker Switch ACC ---------> 1 of 2 Small Posts on Solenoid
12V Illuminated Rocker Switch GND -------> GND
2 of 2 Small Posts on Solenoid --------> GND

This works only when the Rocker Switch was turned on and the ACC was on. That was my intent in the beginning.

The Solenoid is rated at 100,000 cycles at load (85A continuous). I am thinking this should be as good as a 70A relay. What do you guys think?

 

If you're still looking for a 70A relay and fuse www.digikey.com has them. They are a great source for electronic parts. I've never had a problem with them.

 

Glad you got it figured out.

I guess you've tried it out and it works fine?

This worries me only because if it were a ford solenoid (which looks very similar) you'd be grounding 12v when it is on. Making a huge short and melting something down. I don't know exactly how those cole hersee ones are built, so I could be wrong, but usually the ground for the solenoid it self is made though the mounting bracket.

 

Yes, it works when I grounded the solenoid otherwise it wouldn't turn on. I haven't run it long though. This solenoid happens to be from a different manufacturer and has isolated pads on the mounting surface so I am ***uming it means that it is an isolated solenoid.

Cole Hersee had this diagram for GND on solenoids:

 

LOL if you can't afford 2 bucks for a relay then you've got the wrong hobby, Jack!

I explained in painful detail how to do it, then showed him where to look for the parts/knowledge.

Seriously, how hard is this to do if you insist on being that ignorant?!?

So what are you going to do next?!? Run the battery to the hot side of the solenoid with the alt +, then run another gauge cable from there to your starter solenoid?!?

Sure, if you were actually running a remote solenoid for hot start that would make sense, but you're gonna make/buy another battery cable and create more points for corrosion/resistance/terminal failure to try and save 2 bucks on a relay and spend $6 on a cable?!?

This is the stupidest idea ever. Just some ME on a personal jagoff theoretical project and begging for help when he's too damn lazy to search the net or even read what's in front of him.

Revhead why you'd even encourage this douche is beyond me. I hope he wires it up correctly and gets the fan runnning before he slams his head into it

This tool has been asking this same question since 2006.

09-08-2006Installing an Electric Fan..Is this right?I'm installing an electric fan in my shoebox and I want to make sure I am wiring this right (please see attached "crude" diagram). The toggle switch is an illimunated version but I don't know what terminals 2 and 3 are for. As you can see I am no electrical wiz ! Thanks for any help!!!

You can't read a book or do a search in 3 years?!? That's what I did when I needed to learn how to wire! I guess you're too busy complaining about Internet courage, just a mouse click away... on multiple threads to bother reading all the good advice given to you.

Take a look at the posts Mr. ME has contributed...oh wait there aren't any for the last year or two...and I sure don't see much help he's been giving anybody except some advice on how long it takes gasket maker to dry...thanks for your....opinion....you'd think an ME would have maybe a little more expertise than watching glue dry, but judging from this abortion of a wiring job I guess not.

 

I don't know you Johnny1290 but I don't spend my life on this site or any others. Looks like you have a lot of time on your hands judging by the number of posts and your thorough research of me. Get a life!

PM me and we can settle this anyway you want. Posting this on a board shows what a child you are since you need the approval of others.

 

How about threatening to kick someones *** over the internet? Is that childish?

Sure, here's how I want to settle this. Prove me wrong, jack***! LOL You wouldn't be so pissed but you know I'm right and I proved it! hahahaha

hey see ya in a couple more years when your $1.98 illuminated k-tel rocker switch burns out and you need more 'help' on wiring up your fan!

Here's to your return in '11!!!

EDIT: I forgot to say come back soon, there's no such thing as a stupid question!

 

That looks, to me, like a continuous duty solenoid. I didn't see any I or S in the pic. This is exactly how we wire our main panel power control systems in power company aerial trucks.

Apply power to either of the small posts and ground the other and the solenoid should actuate.

Perhaps you have your toggle switch miswired. Easy to do with an illuminated switch (with three tabs)

 

seriously? who the **** are you Johnny? I know this doesn't involve me, but I am sick of seeing jack***es like you on message boards ripping into people cause they don't do things like you say they should. all you've done to this post is turn it into a ****-slinging contest because instead of helping you decide it is better to point out how ignorant you think someone is. Well you're the dumb*** that said it couldn't be done with what he's got and ...WOW what do you know, he's got it working now!

The only electrical savvy you have apparently is what you read on MAD electrical's website..

people like you ruin this place.

 

Yeah my earlier post should be ignored, I didn't know what kind of solenoid he had at the time

 

...but using a continuous duty solenoid, which looks nearly identical to a starter solenoid, is the preferred way of switching high current. FoMoCo uses this method for switching auxiliary batteries in and out of the charging circuits (instead of more expensive battery isolators)on their RV ch***is designs.

 

Yes, some of the newer, thin profile, fans use a LOT of power.

 

This thread is 114% pure comedy gold.

 

A pair of Spahl (sp) fans fried the connectors and relay setup in **** Rigoli's pro street '62 Chrysler 300. We had to make some serious changes to the manufacturer-supplied connectors to handle the current because the fans ran all the time, even though they were controlled by a thermal sensor. A built 517 Indy motor tends to run a tad warm.

 

Just an innocent question, any reason why you're not running the mechinal fan?

 

It is if it's a continuous-duty model which, if his picture is accurate, it appears to be.

We put these in trucks to switch on all of the power take off and lighting circuits. We rarely ever have to replace one and when we do, it's almost always because of a poor crimp on the wire caused the wire to heat up and melt the insulation as well as the nylon insulator around the stud. A lot of people don't know how to adequately crimp a wire but don't get me started on that subject again.

 

Continuous-duty solenoids aren't wired (internally) the same as starter solenoids. The pick coil is not internally grounded as it is in a starter solenoid. You have to connect power (switched or otherwise) to one side and ground (switched or otherwise) to the other side. You can switch either post (power or ground) and get the solenoid to work as long as one side or the other is unswitched.

With a starter solenoid, the body of the solenoid must be grounded and switched power must be applied to the "S" terminal to actuate the solenoid.

 

Personally, I'd never put a Bosch relay on a fan circuit UNLESS I knew the rated output. The cheap Bosch-style relays you find at the auto chain stores aren't good for more than 15 amps and, if you install them outside, under the hood, they get filled up with moisture and, eventually, rust.

Even though they look the same, these relay can be rated anywhere from 10 to 50 amps and, unless I know what the actual rating is (and it's usually NOT printed on the relay) I simply won't use it.

Another issue is that, were I to use an adequate relay, what's to stop some wet behind the ears kid from swapping it out in a misguided troubleshooting scenario? Beter to do it right the first time and not have to do it over, later.

Also, if I have to mount a relay outside the cabin, it had better be a waterproof relay (expensive) or a solenoid, instead.

BTW, a MICRO-SWITCH can be used to switch a relay on and off so what's the big deal about a k-tel rocker switch.