So I have the 1986 Camaro IROC Z. A while ago my radiator fan stopped working. Everything relating to the fan was replaced (ECM, Fan motor, relay, pigtails, CTS), it never came on. I had a shop look at it and no one could figure out how to get the pre-fan switch era fans to come on. So I brought a Hayden fan controller in March. It was running fine until about a month ago and stopped working. I was looking for electrical shorts but couldn't find any. This morning when I started my car and drove maybe 1/4 mile down the street at 15 mph, I saw smoke coming from the front driver's side of my car where the lights were. I stopped, killed my car, popped the hood and sure enough smoke was coming from the fan controller. Does anyone know the cause of this? Does anyone know of a fan conrtoller that is reliable and won't burn up after 6 months?

 

Something down stream of the relay shorted to ground. Either something within the controller or the fan wiring or the fan motor.

Either that, or fan is drawing too much current for this controller and it's continually getting very hot, and over time internal insulation failed causing an internal short.

 

Thanks. Do you or anyone know of a fan controller that works with the single fan or a way to make the single fan work? It's frustrating that no one can figure it out. I just want my cooling fan to work.

 

That looks like just yerbasic automotive relay. No doubt the "controller" operates it to turn the fan(s) on.

Probably not enough current-carrying capacity to handle the load of the fans; either the relay itself, or possibly, whatever is in that "base" that it plugs into.

Probably not a "short" as such (2 wires touching that shouldn't be or the like), although it could be; more like, it was simply inadequate to the task in the first place.

If the "controller" is still good, you could get a heavier-duty relay, and mount it externally; and plug the terminals from the new one's coil into the corresponding terminals in the base with acoupla jumper wires, and connect the +12V and the fan power lead directly to the new relay's contacts. Something like this. https://www.racetronix.biz/p/relay-c...s-iso/rycs-003 Maybe even use 2 of them if you have 2 fans.

 

It's the single fan with no fan switch. So I was recommended the Hayden 3652 by this forum. Does anyone know of a good fan controller, that can handle the load of the single fan?

 

I unplugged the relay on the fan controller, so that kept it safe to drive for the next couple of days? I'm only planning on short trips.

 

you can build your own controller... I'm running one of these 75amp relays on each of the low and high speed on my Taurus fan for the last 10 years or so and that thing pulls some serious current. I too burned up one of these "Pep Boys" relays with that fan and a 40 amp relay, which is what steered me to the 75amp. For a circuit that draws so much current, I want a lot of margin on current capability.

Bosch 75amp relay.
https://www.summitracing.com/parts/sum-890117

185 deg temp switch
https://www.summitracing.com/parts/sum-890117

One of the large terminals goes to the fan power, the other to the battery. Doesn't matter which is which.

One of the small terminals goes switched 12V. The other goes to the fan switch. Again, doesn't matter which is which.

Also, put a fusible link on the battery input to the relay. Fusible link should be numerically 4 sizes larger than the gauge of the wire... i.e., an 8 awg wire protected by a 12 awg fusible link. That way if something shorts, the fusible link will prevent a repeat of what you just experienced. Some people put actual fuses, but the problem is the inrush current on the fans can potentially blow the fuse. The fusible link will sustain short duration high current, but if a true short occurs it'll blow.

 

Heat from a poor connection most likely. Those relays are good for 40 amps. That's about it.

 

Seems quite a stretch to characterize driving a car without a working cooling fan as "safe".

 

Well this fan has rarely ever worked. For whatever reason before the fan controller no one could figure out how to get it to turn on. I just meant I don't want the fan controller sparking or smoking again.

 

True dat... but not quite the same thing as "safe".

Honestly, I think if I were in the position you're in, I'd just put a normal fan switch in the head, like it came; a new relay, with at least the ampacity of the original stock one; hook it all back up like it came; and call it a day. At a certain level, the extra complexity such as the aftermarket controller, adds no value. There's a variety of temperatures you can get for fan switches if you're not happy with the OE settings.

 

The problem is the 1985 and 86 years never came with a fan switch in the head. I brought the car into 2013 and the fan for the most part worked up until last year (ECM failed once, motor failed once, pigtail) but since last year I haven't been able to get it to work. No shorts but it just won't turn on (motor works when jumped by battery). But that's the thing the 85 and 86 years are a mystery of how they work in stock form. No one has an answers. There are tons of old threads of them stopped working but the only fixes seem to be a fan controller or find a dual fan set up from the 87 and on years. If I had the 87 and later years, this would be as easy as replacing the fan switch.

https://www.thirdgen.org/forums/cool...re-single.html

 

I am a complete electrical noob. Do you have pictures of your set up? Also my 1986 doesn't have a fan switch, so I'm not sure if there is a place to put that fan switch.

Also the Hayden controller did have two 30amp fuses, neither of them blew. What would that mean?

 

Then put one there. Piece o cake. Beats some POS aftermarket thing that doesn't last. Yeah we were all kinda dancing around the whole "POS" thing, but really I think, that's at the core of the matter.

There is. EVERY SBC head has that place. On the driver's side, it ends up between the #1 & #3 spark plugs, and has a temp gauge sending unit in it: but in the same hole in the same head casting is between the #6 & #8 spark plugs when it goes on the pass side, and it has a pipe plug in it. Or at least always did, up until it had a fan switch instead sometimes.

Unfortunately no. But it's just stock. There are any number of photos of it running around, easiest to find probably in the "what wire goes here" and "where does this wire go" kind of threads. Or, just look at your pass side head, between the #6 & #8 spark plugs; and imagine a fan switch there. Look up the fan switch for say a 84 L69 car. https://www.autozone.com/cooling-hea...sw500/2642_0_0 for example. That particular one comes on at 230ish° and goes off at 210ish°; there are other switches, otherwise identical, except at different temperatures.

That would mean, poor engineering... it was protected (fused) at a level beyond its actual capacity.

 

I can't really get a picture of anything that would be discernable... But in pictoral form, here's the schematic. All you need to is get the terminals and the other components.

 

I'm going to order everything right now. Just to make sure we are clear. I have Summit fan switch (goes in Cylinders 6 and 8), 75 amp relay, 12 gauge fusible link and a 5amp inline fuse. Then I should use 8 gauge wire?

 

Yes, that should do the trick.

For "keyed ignition", use the pink/blk circuit that's all around under the hood. You should easily be able to splice into it somewhere convenient yet inconspicuous, solder your splice with rosin core solder, and cover with heat shrink tubing.

 

Right.

A little tip too since you only have one fan.

Connectorize the fusible link with spade terminals and carry a spare thta's also already connectorized and ready to swap in. Also, a spare relay with a screw drive to undo the screw terminals.

If something happens and you blow the fusible link on the road somewhere (and you are able to identify and fix the problem right then and there), you can swap in the new fusible link and if necessary, the spare relay too. That way you're not left stranded without a cooling fan.

Since I have a two speed fan with separate relays on separate on/off circuits within the ECM, I have a built-in internal redundancy in the system so for me this isn't necessary.

The 5A fuse on the keyed ignition is very important if you tap into your general keyed ignition circuit. You don't want a short here to take down the whole car by blowing the main fuse. Could even go with a 3A fuse too for more margin against the main fuse (you want this fuse to be far away from the rating on the main fuse to ensure this one blows first).

 

One last question. I have the Hayden fan controller spliced into the pigtail (I believe it's a green wire) on the back of the AC Compressor. I believe this wire runs to the low pressure switch. Before the fan controller, the AC Compressor turned on but the fan never came on for some reason. Would I have to do anything to get the fan to turn on?

 

Hi, for what its worth. I know there are some who don't like it, however I have a Derale controller and its worked flawlessly for several years. It has a small sensor that connects to the side of the radiator and is adjustable.

Louis