It's Official...I Regret Electric Fans!!
 

Well, I just found my fourth electrical melt down in the wiring harness of my Troyer fans since installation. The one I just found was the low temp fan fuse holder. Second time this fuse holder has had a complete meltdown!! (There have been two others, but this is a repeat in this particular location)

This is on a brand new fan too!! When I installed my new radiator in September, I discovered the fan was shot. Replaced it (with the Derale 16") at that time. Every single connection is saudered (sp??), every plug in had dielectric grease. Fan controllers seem to be working fine. Turn on temps work with no notable problems. No funny happenings to suggest a bad controller. I can not find any reason why this just unexpectedly happens from time to time.

But I can tell you this...the worry of buring up my truck has officially exceeded any performance gains that comes with these fans.

I'm more or less venting (and sharing my experience) than asking for advice, but if you guys have any ideas why this happens or what can be done to prevent it, please...Let me know!! Thanks guys.

You have in-line fuses on the hot wires ? Does the kit come with resistors by chance? Do you have the Troyer install guide via "Truck World" web site . ?? I'll find it for yuh if you don't.. - They have an awsome write up with pics on "how to" wire it in..

BTW -"saudered" = "soldered" :D

I had a fuse holder melt down after a year of service from it. I replace it with a circuit breaker, which seems to work fine.

Yea jb, it's the 35 amp fuse/fuse holder in the hot wire. Fuse is located in that line between the battery and the controler. No resistors that I know of. Was installed ver batum according to the directions that came with the fan kit.

If it matters for troubleshooting, the fuse holder assembly looks like it melted down on the controler side, not the battery side. Looks like it continued to melt until the circuit opened. Why on earth this would happen instead of blowing the fuse is beyond me??

Also for FYI, it had a 30 amp fuse in it this time. Don't remember what was in it the last. I guess I could try a 20 or 25 amp fuse but then it'd probably pop the fuse every time it turns the fan on. I still don't get how it can burn that thing up and not blow the fuse though??????????????????????????

Huh, what size is the hot wire - 35 seems like allot . I run a 45 with 6 awg.

Here's a chart -

http://www.hotrodsandclassics.net/us...dfusequide.htm

Even though you made a decision, here is the scoop to help anyone with these problems.
There are electrical laws that cannot be violated by anyone, no matter who the designer/vendor/builder etc is.
The reason your fuse holders melted is that there was to much resistance accross the part. This caused voltage drop accross the part. Voltage drop times the current passing thru equals the watts of heat it took to melt the parts.... Example: 30 amps thru a .5 ohm resistance = 450 watts of power or by law; 30 x 30 = 900 x .5 = 450 watts..
This is enough to melt the holder.
.
What a circuit design must address:
1. correct min size wire.
2. correct fuse holder for the current being passed plus some capacity above that for protection.
3. absolute min to no resistance in any part of the assembly or connections.
4. fuse holder that grips the fuse tight.

A fuse holder that melts quite often does not blow a fuse in the process because it keep dropping more and more power until IT burns open. This won't blow other larger fuses in the line because as the bad resistance builds the circuit current become 'less' and won't blow some other high value fuse..
That's all there is to it besides good workmanship and proper sizeing for the application.

Now that I read this post I'm starting to debate if I should install a Lincoln Mark VIII fan that I have. Have any of you guys installed this type of fan on your truck? How is the fit?

Additional insights:
Changing fuse size for a problem of melting does not address the problem.
Remember that a blown fuse is a BURN OPEN action in it'self, but internal to the fuse where it belongs and not outside melting the holder down.
To burn open a fuse, it's internal 'link' is made of lead/tin that is rated to melt when the current thru it reaches a value that heats the link to it's melting point.
Further, a holder that melts due to increasing resistance accross the 'holder' will have more series resistance than the fuse it holds. **
As the resistance rises from the heating action, the circuit series resistance rises and begins to 'limit' the total circut current. **
How does this work: look at these examples; current = 30 amps, resistance = .5 ohm, voltage drop = 15 volts. Now figure the current when the resistance is .75 ohm.
I = e/r or 15/.75 = 20 amps, showing that the curent goes down when the resistance goes up and becomes a limiting factor such that some other fuse in the line won't provide any protection. ** unless a lead with power shorts to ground or another lead that is grounded, after the damage is done.
Working with these things needs an understanding of the needs of the circuit or trust in the supplier that the design is reliable and correct. If not, OH WELL!.

Heres the link to the Troyer E-fan full install with great pics - including wiring -

http://www.ford-trucks.com/article/i...c_Fan_Kit.html

Might be helpful for comparison.

The Mark viii fan assembly takes an enormus amount of starting current.
You need to engineer the circuit to handle the max. starting load besides the running load.
Decide how you will control it and to what degree.
The cars have a control board design that worked very well.
Doing anything less is asking for trouble.
The total controller circuit can be found in the Ford fuel injection book by C. Probst, page 338, or the Ford diagnostic disc for 93.
The Taurus fan is also current hungry and uses a controller circuit.
Both these cars had large alternators and considerable battery capacity.

hello

don't forget about the fact a bad ground can cause the fuse holder to burn up also:beers:

I mounted a 2 speed taurus fan into my stock shroud......only need the low setting to cool my engine down. Amazing little fan, but it does draw a lot of current when it first clicks on.

Bluegrass....great lesson!! But doesn't really tell me what to do about it (unless you had some secret message burried deep in there somewhere and I just can't pull it out). This is Troyer's design and the installation was followed to the T. While everything you said made perfect sense, I sitll don't know how to address the issue. So what exactly would you do to try and remedy this little problem??

LOL - Well, ANYWAY - I would first match the wire thickness (AWG) to the recommended fuse. If you have or if the manufacturer has correctly, then IMO you have a defective product .

Is the truck drivable at this point . That would suck if it wasn't - I would want to get on the horn to Troyer , you have a pretty serious issue that would make me want to put back to stock so I didn't have to worry about it..

If I remember right , you have quite a bit invested in your truck and it looks pretty sweet. I wouldn't want to take any chances with it..