Taurus Fan on V8 Chevy Z

[jack46]

I agree two in parallel is well NOT ideal.

 

I don't know why the relays aren't higher really they are fine for lights etc fans they are weak at beat.

 

Like I said I have to relocate mine since I'm rebuilding tranny I will pull motor and redo it all. I had lights come on in rain last visit to track. Only happened once but that will happen again.

 

My typing is terrible tonight if I didn't know better I would say I was drinking. I have had to retyp and edit more on these three posts than I care to admit.

[Guest boosted]

Im currently running only high speed and an adjustable temperature switch. 2 30amp relays and 40map fuse. One fan took a poop on me already and i figure it was just its time to go. Now the second fan is starting to act up. seems only when it has been running for a few minutes. its slowing right down. I dont think ive got it wired incorrectly but wonder if somthing is wrong since the fans seem to be croaking out on me.

[Bartman]

I want to rewire my fan to work using the outputs from my LT1 PCM. Here's Larry's wiring diagram:

I think this will generally work, but Larry is showing fusible links instead of regular fuses. Should I use fusible links or not? The other inputs for the relays will be from my PCM. I will purchase the VF7 relay and parts that Pete recommended in his post on another thread. http://forums.hybridz.org/showthread.php?t=99700&highlight=taurus+fan+wiring

 

I would really like to figure out what parts I need in addition to the one's Pete provided in the link above. It seems like Newark would be a great place to get everything, including the low speed relay, connector, and any required diodes.

 

I'm currently using a Painless auxillary fuse block that has a built in 30 amp relay. Can I use this, or do I need a different solution for fuses?

[jack46]

Larry is showing fusible links instead of regular fuses. Should I use fusible links or not?

Fuseable links or fuses both limit the current that can flow to a circuit. Fuseable links are ‘slow’ blow where fuses tend to react faster. On a high current start like fans fuseable links are better because they allow the current to momentarily exceed their rating.

 

The other inputs for the relays will be from my PCM. I will purchase the VF7 relay and parts that Pete recommended in his post on another thread.

 

Remember to include a diode if you will also use a switch to override PCM or you could damage the PCM. I have mine in an LT1 Z.

[Turbo Meister]

Turbo Meister, you got any video of that z tearing up the pavement. What a ruthless combo man...I am blown away!

 

Of course I do.

Just go to my Photo Gallery or to the Video Section of the Photo Album.

Hanns

[Bartman]

Fuseable links or fuses both limit the current that can flow to a circuit. Fuseable links are ‘slow’ blow where fuses tend to react faster. On a high current start like fans fuseable links are better because they allow the current to momentarily exceed their rating.

 

Remember to include a diode if you will also use a switch to override PCM or you could damage the PCM. I have mine in an LT1 Z.

Thanks jack46. I found some information on the web which supports exactly what you stated. In fact this guy sells them too.

http://www.madelectrical.com/catalog/fusible-link.shtml

This web site also talks about and sells relays and recommends using two relays in parallel instead of using one high power relay for electric fan installs.

http://www.madelectrical.com/catalog/rly-1.shtml

I think I'm going to call this guy and order the stuff I need from him.

 

Jack if it isn't too much trouble, could you post or send me a diagram for your setup? It sounds like you have exactly the setup I would like to use.

[pparaska]

If you call MAD Electrical, you will be deluged with tech info. I've spent hours talking about electrical stuff with him - he lives, eats, and sleeps auto electrics and will talk your ear off! That's a great thing! However, everything he has told me and written in magazine articles and on his site is very good stuff.

 

Interesting that he likes two relays in parallel to one. But the VF7 relay uses a larger blade connector on the arm and contact than the VF4. However, two VF4 connectors in parallel are probably better than one VF7.

 

The other thing to consider is that VF4 relays are EVERYWHERE. VF7 are special order in most places.

 

I personally like his tirade on how NHRA is making people switch the wrong side of the battery with their emergency cut off switch. The MAD proprietor thinks it should be on the negative side of the battery, between the battery and all ground connections. In a crash, if the switch terminals get in contact with bare metal (grounded), nothing would happen except maybe the switch would be short circuited, not able to unhook the battery from the car. The way the NHRA wants it, if the terminals hit sheetmetal, you have a hard short of the positive side of the battery to grounded sheetmetal - not good!

[Bartman]

If you call MAD Electrical' date=' you will be deluged with tech info. I've spent hours talking about electrical stuff with him - he lives, eats, and sleeps auto electrics and will talk your ear off! That's a great thing! However, everything he has told me and written in magazine articles and on his site is very good stuff.

 

Interesting that he likes two relays in parallel to one. But the VF7 relay uses a larger blade connector on the arm and contact than the VF4. However, two VF4 connectors in parallel are probably better than one VF7.

 

The other thing to consider is that VF4 relays are EVERYWHERE. VF7 are special order in most places.

 

I personally like his tirade on how NHRA is making people switch the wrong side of the battery with their emergency cut off switch. The MAD proprietor thinks it should be on the negative side of the battery, between the battery and all ground connections. In a crash, if the switch terminals get in contact with bare metal (grounded), nothing would happen except maybe the switch would be short circuited, not able to unhook the battery from the car. The way the NHRA wants it, if the terminals hit sheetmetal, you have a hard short of the positive side of the battery to grounded sheetmetal - not good![/quote']I just got off the phone with him, and he's a wealth of electrical information! I ordered everything I will need from him, including a diode so that I can install an override switch to turn on my fan manually.

 

P.S. - I definitely had it wired incorrectly using power from the battery instead of the alternator (especially if your using the stock amp gauge). The way it is now when the fan is turned on the amp gauge moves more towards the charge side (which Mark verified would happen if you wire it like this). I guess this is very bad for the gauge (and the whole charge circuit). I ordered his book too, so I can learn more about electrical work and how to do it properly. I also purchased an insulated terminal block to connect between the alternator and the relays. I highly recommend using him as he will help ensure that you do it the right way the first time...just make sure you have enough time set aside to talk to him.

[Pop N Wood]

If the wiring is too small in the total fan power circuit (like running it from the harness like Tim has) then you get less voltage at the fan due to the wiring acting like a resistor. Electric DC motors tend to draw less current when run below their designed voltage. [url=http://www.gizmology.net/motors.htm]http://www.gizmology.net/motors.htm[/url'] That could be one reason that Tim's 20A fuse hasn't blown.

 

Other way around. Lowering the supply voltage increases the current draw.

 

In a DC motor, the speed is almost directly proportional to the supply voltage. See this link

 

http://homepages.which.net/~paul.hi...ors/Motors.html

 

If you look at this plot

 

 

You will see that current goes up as the speed goes down. So lower voltage, more current.

 

If you run a DC motor significantly below it's design voltage, the motor efficiency drops off and the current draw will go up rapidly. Just like using too long of an extension cord on a power tool. Motors are much more complicated than simple resistors. Get them out of their designed operating band and they can go exponential on you quick.

 

Here is a companion link from the same site.

 

http://homepages.which.net/~paul.hi...ksBody.html#2.6

 

Maybe I didn't catch it, but I don't think Turbo Meister listed what gauge wire he was feeding the fan with. If that is too small, or there is a loose or corroded connector, then this will cause insufficient voltage at the fan and can greatly increase current draw. Fusible links and fuses are also resistors and can cause voltage droop. Dirty or corroded relay contacts (often caused by excessive arcing) will do the same (just like dirty points).

 

If he is blowing fuses where Tim is not, then my guess is he has a poor electrical path to the fan, a bad fan or a partial short to ground somewhere.

 

My advice is make sure all of your connections are tight and wire of sufficient gauge is being used to power the fan. Measuring the voltage before and after each connection with the fan running will tell you where a poor connection or undersized wire exists. If you have 14.5 V at the battery and only 10 V or so at the fan, then you might have a problem. I am not sure exactly what numbers to put on it.

 

Also I have worked with a lot of circuits which use diodes to absorb the inductive kick of the relay solenoids. But most of those where fairly substantial relays that were being used with sensitive electronics. I would be a little surprised if these relays used on a car fall into that category. But if the manufacturer is recommending a kick back diode then by all means use one. Do any of the car manufacturers include such diodes on their stock relays?

[Turbo Meister]

Maybe I didn't catch it, but I don't think Turbo Meister listed what gauge wire he was feeding the fan with. If that is too small, or there is a loose or corroded connector, then this will cause insufficient voltage at the fan and can greatly increase current draw.

 

I'm using a 6 gauge wire and the connections are tight. I didn't have a problem after I installed the 60 amp Maxi Fuse between my power distribution point and the 2 30 amp relays. Previously, the same set-up except for the 30 amp fuse in the identical location, caused that fuse to blow. But only when I started the engine(probably from a power spike).

 

I've raced the Z and driven it on the street since the installation and the fan works great. It's been 95+ degrees here every day and the water temp stays at or below 180 degrees.

Hanns

[jack46]

Here is the circuit I used on my LT1. Sorry for the pic size, my photo

program decided it needed the month off. I love MS products?

 

Note other side of fan coils are connected to ground. Mine is in car so not

sure color codes on mine, but easy to find with ohm meter and applying power.

 

It is same circuit from earlier in post just has relay connection numbers,

shows flyback diodes and only shows as puller (Fan on engine side of

radiator).

 

 

I wasn't sure if you still needed it, but thought someone might want to see

what we all meant in this thread.

[Bartman]

Here is the circuit I used on my LT1. Sorry for the pic size' date=' my photo

program decided it needed the month off. I love MS products?

 

Note other side of fan coils are connected to ground. Mine is in car so not

sure color codes on mine, but easy to find with ohm meter and applying power.

 

It is same circuit from earlier in post just has relay connection numbers,

shows flyback diodes and only shows as puller (Fan on engine side of

radiator).

 

I wasn't sure if you still needed it, but thought someone might want to see

what we all meant in this thread.[/quote']Thanks for posting this, I think it will be a big help for me. I think you answered one of my lingering questions in regards to how I can prevent both high and low being turned on at the same time (like if I had my high override switch on, and the PCM enabled the low fan). It looks like the way you have the relays wired, you would only enable high if both high and low are energized. The only thing I don't have is the flyback diodes between the fan and the relays. I will try to find those and add them as well.

[jack46]

I think you answered one of my lingering questions in regards to how I can prevent both high and low being turned on at the same time (like if I had my high override switch on, and the PCM enabled the low fan). It looks like the way you have the relays wired, you would only enable high if both high and low are energized.

 

Correct high from switch or ECM will override the low, and only the high coil will be energized with my circuit. Also if low switch is on and ECM turns on the high etc. This will work fine with an LT1

 

The only thing I don't have is the flyback diodes between the fan and the relays. I will try to find those and add them as well.

Well as discussed they are worth the time to install they are cheap.

 

Good luck

[jack46]

Turbo Meister

 

I just read your post. I thought I was conservative using two 10 guage wires, but you used 6 guage. I believe in heavy guage wire for high amperage. Harder to work with but it is never a problem with the load heating it up.

 

Look forward to seeing more videos of your beast. My AC went out so I am doing nothing. AC in garage has spoiled me, and now that it is out I can not lift a wrench.

[waynekarnes]

i was reading at the site Pete recommended .. about chevrolet's engineers and how it was recommended using 4 ga. wiring ... but due to the way they ran the wiring, various voltage drops lowered the amperage and current, yet left enough to get the job done on the smaller ga wire without toasting it.

 

suggested leaving original wiring in place and adding a heavier ga wire along side it from alt to batt or junction point. electricity will follow the thicker wire, easier path.

 

very interesting read ...

 

i think i am going to get the 3 wire 100 amp alt.

 

seller on ebay ...

 

a-1truck@sbcglobal.net

 

sent me this message ...

 

wayne we carry a 100 amp 3 wire alternator with a special turbo fan for added cooling.either natural or chrome.the natural is 95.00 and the chrome is 135.00 plus 16.00 shipping. thanks john

 

 

his ebay ad says new, not rebuilt ... he doesn't mention here if new or rebuilt ... if on his site is new, this may be as well ...

 

pay some bills and such, see if anything left over ... i think that this is something i am going to need ...

[zardoz337]

I have enjoyed reading the posts and there is some great information here! I just wanted to add a bit of information I have picked up while employed by an aftermarket fan outfit. The thinking was that a fan is functional in automotive applications, up to about 35 mph but after this point the "ram-air" effect took over and exceeded the fans cooling capacity. One of the advantages of electrical fans is that hard mounted fans take horsepower to turn. By using an electrical fan it has the ability to "cut off" above this mph sweet spot (when the ram-air effect takes over) and thus you get a little horsepower gain from it. The electrical fan in theory does not use quite as much horsepower when it is running and none at all when it shuts down. I believe that controling the fan thermostaticly is the best choice as engine temp will determine when this sweet spot is reached. Also it is my understanding that when you shut down a hot engine there is an effect called "heat-soak" the engine will heat up a bit due to the coolent not flowing and the fan being off. Many manufactures have included a circuit to help minimize this effect, where the electric fan will run a few minutes, after the car is turned off, if the temp warrents it. Any just my two cents worth, hope this helps!

Zardoz337

[speeder]

I need a powerful pusher fan - and looking at Jack 46's diagram it appears that the Taurus fan has been used this way.

 

Can anyone tell me how well it works as a pusher? Can you invert the fan blades to be efficient in reversed rotation or do they work as mounted going in reverse?

 

Looks as if that curved blade fan is a directional design....

[Mike kZ]

I need a powerful pusher fan - and looking at Jack 46's diagram it appears that the Taurus fan has been used this way.

 

Can anyone tell me how well it works as a pusher? Can you invert the fan blades to be efficient in reversed rotation or do they work as mounted going in reverse?

 

Looks as if that curved blade fan is a directional design....

 

I don't think the Taurus fan would make a good pusher fan, it has a built in shroud, that would cover up your rad intake, and i don't think it's reversible. I remember Pete saying that his Mustang fan doesn't have the shroud, and is just as powerfull as the Taurus, not sure if you can reverse it though.

[Wolfsblood]

Does anyone have wiring diagrams for a non-computored car..old school 350 with plain jane GM wiring harness...I picked up the 2 speed taurus fan and have to get it wired up to run off temp sender ,..any suggestions /ideas?

[jack46]

Does anyone have wiring diagrams for a non-computored car..old school 350 with plain jane GM wiring harness...I picked up the 2 speed taurus fan and have to get it wired up to run off temp sender ,..any suggestions /ideas?

The schematic I gave will work. You do not include the diodes that hook up to ECM. BUT in your case you will provide a ground instead of ECM. Then you can use switches to turn on low or high and temp will turn on high when 'set' temp reached. You will need a temperature 'switch', when the desired temperature is reached it closes and provides a ground.

 

The 'Taurus' fans I had operated in either direction. I have not run the fan as a pusher for more than minutes. As for the shroud covering the radiator it also covers the radiator in rear so either way will restrict air flow, so caution is always needed to ensure the radiator has sufficent air flow.