dsmrx7

I have the Taurus 2-Speed E-Fan with a thermoswitch hooked up to it. So far it's melted relays twice and one of the relays was even a Bosch. WTF? I use the "high" speed only. The fan's good, my car never overheated when it's running. Luckily I'm paranoid and carry spare everything.

Turbonut

iTrader: (1)

What amps are the relays that are self destucting?
Purchase a 70Amp and if that one melts????????

CrackHeadMel

iTrader: (2)

Bet your running a cheap china 30amp relay, i made the mistake of runnning one of thoes as my walboro fuel pump relay, thing would get so hot it would kick out. It never melted fortunatly, however a fuel pump randomly shutting off in a single turbo car makes for some intreasting ohshit momnments

jackhild59

iTrader: (7)

The factory fuse for this fan is 40 amp. The typical 30/40 amp relay should be adequate.

2 possibilities. One is that the relay is actually getting hot internally. Two is that the relay connectors/wires are not heavy enough and are heating up.

What wire gauge are you using for the connectors?
Are you using sockets for those relays?

I melted the socket of my high speed relay on my Taurus fan. I use both low and high speed on the fan. I am using a relay socket that was wired with inadequately sized wire. Why do manufacturers wire sockets for use with 30/40 amp relays with 16 ga wire(10 amp) or 14 ga wire(15 amp) ???

I am currently waiting for some parts to arrive. I will then be able to check the running amps of the fan, rewire my sockets with heavier wire that is the correct gauge for the amperage load. Then and only then will I be able to determine if the relay is getting hot or if it is being caused by the wiring.

Here is a link to my thread on the same topic. This weekend I should have everything back together, tested with some pics up. When I am done, I will have answers.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/my-taurus-2-speed-e-fan-experiences-774799/

hondahater

iTrader: (2)

Got any links to the relay you use now?

dsmrx7

I'm using the sockets. The first relay that melted was a 30 amp Bosch, second was a Radio Shack 30 Amp that melted the outside covering of the relay and it still worked...never melted the socket yet though. So if i run a 70 amp relay that would fix the problem??? (I'm running the FD alternator.)

Aaron Cake

iTrader: (1)

Keep in mind that a 30A relay may be fine to keep the fan running once it's started, but the fan pulls some serious current (70A +) for a second or so on startup. So uprate the relay accordingly. Also a small value capacitor across the contacts will help prevent them from burning on make/break. Any of the big relays required will have screw terminals, not spade connectors.

arghx

iTrader: (3)

Aaron can you post a link to the relay you are using for your car, or provide some information on where to get one that is proven to work with no BS?

Aaron Cake

iTrader: (1)

I don't use a relay to control my fan anymore. I'm using the FAN-PWM (which I sometimes love, but often hate). When I did use relays I tended to use regular parts store 30A relays as the fans I use don't draw anywhere near the current that the Taurus fan uses. However good relays are made by Omron or Tyco.

jackhild59

iTrader: (7)

Good point, Aaron. One thing that I learned is that t 1/4" spade terminals have a 30 amp (+/-) capacity. This is supported by the fact that the typical spade terminal fuses have a max capacity of 30 amps. Oh, I found that you can buy a 40 amp fuse, but the fuse holder company will tell you that the max capacity is 30 amps. You will also not find an oem fuse requirement that is over 30 amps in this 1/4" configuration.

These relays we are discussing have 1/4" spades. This means that the theoretical current capacity for these relays is likely in the 30 amp range. You mightget away with a few amps over, but you are asking for trouble.

I have found a few relays that have 3/8" spades on the current carrying terminals, but I cannot find any sockets for these relays.

Rob XX 7

iTrader: (8)

so lets get it straight- we wil keep melting relays and potentially overheating the car to get the benefit of running a inexpensive junkyard fan?

There are plenty of 3000-3600 CFM fans that draw ALOT less power then the Taurus fan, plus you get a warranty with them as well!
Zirgo makes a 3950CFM fan with a lifetime gurantee, plus the motor is replaceable so you dont even have to take everything apart, I believe it draws 16 amps.

Aaron Cake

iTrader: (1)

Yeah, basically.

jackhild59

iTrader: (7)

Rob-

This is not busting on you, this is analysis of the Zirgo (and other such fans) that are in the after market.

First of all, we have the assumption that the Taurus fans draw X amount of amperage and moves x amount of air. I don't believe any of the claims, so I am going to do my own measurements of current draw.

Second of all, have you looked at the spec sheet of the Zirgo fans? The pdf from the Manufacturer is a mess. The CFM rating chart has the labels on the wrong axis, the rated current draw on both the ZF16S and the ZFU16S is the same , 10 amp+/- .5 amp, yet the ZFU is 3900 cfm and the ZF is 3300 cfm. They rate them at different voltages, one at 12v and one at 13v. And what is the static pressure measurement on the (wrongly labeled) static pressure axis? Is it in inches of water or did they forget the decimal point? Hell, even the rated amps X the rated volts don't even come close to the rated watts. They don't think that the customers will do this simple math? Or maybe they cannot do this math! Who knows?

Spend some time plugging the numbers into a fan calculator, and you find that the numbers are a real mess.

I hate bad information, but it really pisses me off when it is documented in a way that is intended to deceive the buyer. These spec sheets are clearly not just bad translations.

They look like very nice fans. They might work just fine. We just cannot base this assumption on the manufacturers data sheet which seems to be as bogus as the Taurus fan charts posted over on the 'Stangnet forum.

This is why I am more interested in using well engineered oem fans.

Rob XX 7

iTrader: (8)

the current draw of the taurus fan has been already been documented by many with real world tests using meters, I dont know how one can measure CFM themselves. I would like to see someone measure the CFM of the factory fan- but would like both tests of CFM to be done with shrouds or both tests being equal.

I dont pretend to know what those PDF sheets say, I see someone advertise 3950CFM and I figure it has to push at least 3000, if I read 2100 I figure 1600, I just error on the cautious side

jackhild59

iTrader: (7)

Ok, I had lots to do today, but since I have been shooting off my mouth on this subject, I went to the garage with my new ammeter. No, it is not a test meter. Yes, we could argue that it is or is not accurate.

This was a sloppy quick wire in, but here it is in living color:

Ok, boys and girls, the Taurus Efan on MY RX7 pulls 15 amps on low and 25 amps on high. There is about a 30 amp spike/draw upon startup on low speed, about a 50 amp spike/draw on startup on high speed. If the fan is running on low speed then the a/c calls for high speed, there is about a 35 amp spike/draw.

No ****. Who would have guessed that all those number batted about on the net were bogus?

Aaron Cake

iTrader: (1)

How are you measuring this? I assume you are using a shunt resistor with a datalogging meter or scope. Otherwise you won't get an accurate reading. What value shunt?

Rob XX 7

iTrader: (8)

no offense dude but I would trust a Fluke Multi meter over that gauge

slo

iTrader: (1)

I did the same unscientific test, and what I saw was more like 60 amps at startup.

However, I did it on a new, after market ebay 2 speed taurus fan. In my previous experience I have noticed that new motors can draw allot more current then used ones.

What I also saw was that the Taurus fan would blow a 45 amp breaker on startup to HS much of the time. I have often thought that the solution to this is a cap that would give the fan some additional startup juice.

jackhild59

iTrader: (7)

Doesn't everyone tell us that we need actual gauges to tell us what is really going on with temperature, oil pressure, volts, boost pressure etc.? Shouldn't the same standard apply to a gauge measuring amperage?

I don't think it is unscientific, it is just a field test. I know it really happened on a real car with a real gauge, as opposed to all these internet scientists who measure it with their amprobe clamp-on meter.

Hmmm, might be some difference between the aftermarket oem replacement and the actual oem. We can't get a 'new' oem without buying a new motor from Ford, so we just have to wonder

I have a 40 amp fuseable link installed in the main fuse panel, along with the EGI and other fuses. I have had no problem. I had trouble blowing a 30 amp fuse on startup...

Did you see similar running amperages on the new oem replacement fan?

BTW, was that the one sold sometimes on ebay?