OK, so after going through a whole slew of problems last summer with my permacool fans, now i'm getting trouble from the fan controller. More specificly the power wire that runs from the battery to the controller. Last summer it ran fine (probably because it never really had the chance to run both fans at the same time as one was usually broken).This summer it's decided that it wants to melt the insluation to the power wire and melt the fuse in the holder as well. The wire gets really hot with both fans running. The fact that the wire runs right next to the fuel lines doesn't make me feel any better.

Just for reference it's a flex-a-lite fan controller operating 2 permacool 12" fans. it works great, i followed the install instructions to a T, but it seems like there is too much load being drawn through the power wire for some reason. weird thing is, it didnt pop a 30 amp fuse, or even the 20 amp fuse i replaced it with. the 30 amp fuse melted along with the wire (will post pics later).

SO, i cut one of the fans out again to drop the amount of power being drawn through the wire, but on hot days my temps start to climb. It's not going to get any cooler in the next few months so what do you all think the problem is? think i need a bigger gauge power wire with a bigger fuse? (bigger physically not amps)Is one of the fans drawing too much load? if it is why didnt it pop the fuse?Any help would be appreciated.thnks

check your ground to your fan controller. I had the same issue and my ground for my fan controller was loose.

checked, groud conntected at the battery is good, ground connection at the controller is good :-/

Hi Bronze, you're melting the wire because you're drawing way too much current for the thin turn-on signal wire. It's easy to solve though, you need to use thicker wire and some relays. Basically the fan controller will switch the relays on and off (low current) and the relays (wired with thick-azz wire) will switch the fans on and off (high current). Same way your headlights work, the switch turns the relays on and off it doesn't light the bulb itself.

Replace any melted wires. Now for each fan, run some thick (~10ga) wire from the battery, to a 30a fuse, to the relay, to the fan. Now wire the turn-on signal wire from the controller into each relay. Ground the last wire on the relay. Be sure you ground your fans using the same ~10ga wire. You should keep a small 5-10a fuse inline on the fan controller's +12v off the battery. IDK if you're using any thermo switches (I assume the fan uses it's own temp sensor), but you'd wire those into the ground for each relay if you didn't have a controller.



FYI the fuses didn't blow because you're not overloading them, the problem is the wire is the wrong gauge (too thin). The wire gets hot under heavy load, and melts the insulation (makes a fire?). If the insulation was melted enough and the wire shorted out, you'd blow the fuse.

Also here is a chart that gives a basic guideline for wire size vs amps. You should run some good sized wire for the fans, 10ga should be fine.



Here's the internal schematic of a generic 12v relay with the pin #s. Where he has the fan switch just imagine your fan controller. You can ignore pin 87 (fan off light) if you want.



Cooling & electrical problems are bad enough on their own, let alone when they combine forces to team up on you. GL!
Modified by mello88 at 5:19 PM 5/15/2007

you think i can just use thicker power wire going to the fan controller? the controller is supposed to handle up to 20amps, and both fans on full force shouldnt draw any more than 15. if you think thats a bad idea, the relays sound like a great idea, I'm just lazy and would rather worry about 1 wire, than 2 relays and wiring them

awesome diagrams, thanks for those!

I think you'll have the same problem if you do it like that. Because at some point, you'd have to splice the thicker wire to thinner wire and it would melt from there to the controller for the same reason it melts now

Regardless of what the controller is supposedly rated for, I would run at least one relay (if not two).

GL DUDE!

OK, i'll hook up some relays (2 to do it right).

here is a pic of the carnage and setup.

^^^ +1 Wow! Great info mello88. I was thinking the same but couldn't have explained it with the pictures and diagrams like that. Perfect!

Also, personally I think permacool fans blow monkey nuts. I've never used them myself. But, I know 3 different friends that have run them. All three have had issue with them and switched to FAL's or another brand. In all 3 cases the problems ended once the crap permacools were ditched. This is just an observation and I know that some people on here have run them with no issues. But, eh whatever you like. Seriously though, do what mello88 suggested. I'll bet $ it helps.

i HATE my permacools. They work OK now, but I had to modify both of them to get them to work. the stupid pin that engages the fanblade piece and keeps it from spinning freely on the motor shaft broke on ALL 4 of the permacools i've bought. Me and ol carl h had to put new pins in, then tap the end of the motor shaft to accept a self locking nut (way better than the lame press fitting permacool uses) then bolt everthing back up beastorz style.One of the fans works flawlessly, the other is somehow out of balance and shakes some while operating. anywho, yeah they suck but im too poor to ball out for SPAL fans right now :-/

thanks again to mello88, that really is some awesome info for those of us who arn't so good at wiring/electronics

mello88, when i had efans i ran the hks fan controller and use the stock relays in the fuse box to trigger the fans, worked EXTREMELY well.i keep telling bronze mfp to go that route...but meh.

meh meh meh meh meh, what part of NO MONEY do people not understand?I already have a fan controller, I don't need to fork out another 150+ for one. that money could be going to fans that are worth a poop.

and to my recollection carl, you still complained about the efan setup with the hks controller. can't complain about the clutch fan though.

Depending on which fans your using, you may be pulling more amperage than you think.

I am using a painless wiring fan kit with a pair of relays instead of one with two efans. Has proven very reliable.

I fused both relays seperately incase one fan goes nuts it wont blow the fuse for the whole cooling system.

Evan

You will need 2 relays as the fans can pull 30 amps each and proper sized power wires from the battery..

i'm using the FAL controller with 2 ebay 12" fans. no problems.

FAL instructions also tell you to wire in the fans on the high current side. didn't wire in any extra relays either, just using the AC fan relays ( i think there are two of them) and the fuses they are defaulted to.

No ajustable FPR?

maybe i'm seeing double, but is Carl H talking to himself? Interesting thread though....

+1 for the relays. and power each relay individually with its own 30 amp fuse.