fuse keeps blowing on e-fan setup
 

hello,

i have an 88 rx7 t2 10thae, has one of the twin-speed taurus fans mounted to a big core radiator. The problem I have is that I keep blowing fuses. I've tried over-amp fuses and they still manage to pop. The wiring is correct; does anyone know of a better or more reliable thermal relay setup for these types of fans that is beefier? I don't want to do TOO much as I don't want it to light on fire hahah.

The first question is going to be what gauge wiring did you use and what size fuses are you popping?

It sound to me like your not using the incorrect wiring or your wiring it the wrong way. Fuses don't pop just because.

i just used a 185 thermal relay that has fairly beefy 16g wiring, but it was from autozone :lol: do you guys know any personal better thermal switch setups for a high-draw fan?

the fuse on most Fans needs to be 35amp or bigger. Check the relay as that might be cause with a lower rating. Alot of aftermarket fan kits use cheap relays that surge.

The Taurus Fan is a thirsty beast, as shown by its 10awg wires. Mine is fused for 50 amps, reflecting the original setup from its donor car (I have the original CCRL schematics, they're quite clever). As for relays to trigger it, I'm using a Volvo fan controller. My previous setup was a modified Volkswagen relay panel, which accepted high power relays and had some other useful things in it too.

thanks! i'll give it a shot! do you have any recommendations as far as thermal trigger units? do you use a bung and tap? or just one of those radiator inserts?

You mean a Fan Thermo switch? S4 cars (86-88) have a threaded bung very close to the radiator pressure cap on the water pump housing. No tapping needed here, M16x1.5 threads from the factory.
The S5 (89-91 RX7) has a fan thermoswitch that turns ON at 207 degrees, and it works well. Quite a few FD owners use them as it's a plug & play mod for lower trigger temperature (stock FD is I think 215 or something ridiculous). Downside is that the connector seems to be difficult to find. I'm using a fan thermo switch from an early 70s Subaru. Threads into the stock location with no mods (M16x1.5 thread pitch), uses a simple bullet connector and turns ON at 203 degrees. Even on a 20B-REW that runs hotter than hell on a sunday, it keeps it in the happy zone with the Taurus fan on low. Last time I drove the car (yesterday), the fan stayed on for about 2 minutes after I shut off the engine, and turned the key back on. FDs behave similarly, so it's doing the job :)

i tried getting that bung out to swap for like a 185F thermal but I can't get it out and I don't want to bust it :( maybe i'll give it another shot this weekend, as when I had put it away last fall it was still having overheating issues i was troubleshooting. thanks!

PB Blaster should help free it up. Kind of odd that your stock switch is stuck in place. Mine came out very easily, despite being in there probably since November 11th, 1986 (my car's build date). But then again, a LOT of things on my car were unexpectedly easy to remove...:lol:

Taurus fans are a poor choice due to the ridiculous current requirements. Sure they fit the rad, but if they tax the electrical system and are a pain to control, then why bother?

I have lost count of the number of threads in which people are struggling to get these things working.

Spal makes a number of duel fan assemblies, as does Deraile which fit the FC rad. Or you can buy the fans and make your own shroud.

Of if you just want a single fan that fits the rad and doesn't suck down the juice, the Pontiac 6000/Oldsmobile/Grand Am/bunch of domestic shitboxes fan fits the rad perfectly and works great.

http://www.aaroncake.net/rx-7/efaninstall.htm

All these guys blowing fuses are either using under 10awg or wrong fuse amp. and /or low amp relays or just stupidly running 14 gauge / 30a fuse running high .
I've been running this fan for 3 years now without a problem using a continuous duty 85 amp solenoid with proper fuse and 10awg wires.

could you provide any links (purchaseable or not) to relays / wires you have successfully used with this setup? I'd like to go with something that's proven working.

Automotive and Heavy Duty 6,12,24,36,48 Volt DC Electrical Components is a known excellent resource for relays in the overkill category, as well as the reasonable category :lol: They have some nice offerings in Bosch-style relays, rated for up to 70 amps continuous. Had I not found a Volvo fan controller, I would have gone for one of their SPDT 70a relays. 10awg wire can be bought from Jegs or Waytek Wire for about $13

It's one of those continuous duty solenoids ( 15-132 80amp) . Yes it is over kill but I can pretty much throw anything at it. There's just too many cheap China made relays that I don't trust. Unless it's made in Japan, Korea or US, I don't buy it. I've had too many horrors using China made shit.
Use at least 10 awg for ground and power. I'm using 8 with 50amp fuse. Ground is VERY important just as 12v. Use proper fuse rated for the wire.
Use a 12v trigger and other to ground. Easy to install . Heat shrink and make good connections and forget about it.
Like I said, I've had it for over 3 years without any issues. Even if you plan on running the MKVIII that has a huge spke on start up, a solenoid will be fine granted you use a solenoid of at least 100amps. I never install anything to JUST be enough. I can't see using a relay that has small coil to handle higher than 60 amps. It's asking for trouble.
The solenoid has THICK coils. It's HEAVY.
Make sure it's for continous duty.
It is a sealed unit. ...AND...make sure your alternator is upgraded. An S5 will not be enough. S4...forget it. Everyobe should be running an S5 or FD or whatever high amp alternator. Insufficient voltage causes all sorts of problems.

Wire diameter has nothing to do with blowing fuses. If anything, wire which is too small will make the system less likely to blow fuses. Ohm's law.

It has everything to do with the fact that the Taurus fan is a massive current hog. Isn't there something ridiculous about having to use an 85A solenoid to switch an electric fan, when there are better fans out there that move as much air which happily live on a 30A circuit?

I run a Pontiac 6000/Oldsmobile/Chevy/Fiero/million GM cars fan on my 500HP FC with a Fluidyne rad and 2.5" thick FMIC with zero heating problems. Contrary to popular belief, in many parts of Canada we see 35C+ degree days in the summer with nearly 100% humidity. Even on those hottest of days, this fan can maintain 90 degree coolant temps in stop and go traffic. And I switch it with a 40A relay on a circuit fused for 30A.

And I've installed these very same fans on more FCs and FBs (big turbo cars) than I can keep track of with zero issues.

But I do plan to upgrade that fan because it is too much fan at low thermal loads. I'd much rather have a dual fan setup (Derale makes one which nearly perfectly fits the FC rad...I used it on my Cosmo) for a more gradual control.

care to shed some links on thermal switches / relays / fans you used?

How To Properly Install An Electric Fan

Thermal switches are available from several vendors. Such as Spal and Derale. Get the adjustable electronic type that use a scew-in sensor (GM style water temp sensor).

I use Hella 40A weather tight relays, but any quality 40A relay will do (auto parts store).

If you have a standalone, you can use an extra output to switch the fan (through a relay).

thank you! will end up tackling all of this within the next couple of weeks, as i have acquired a new toy to tinker with...