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Is this the best I can do?

summit and jegs sell adjustable variable temp switchs, I think there's one for dual fans also...

I bookmarked that site /forums/images/graemlins/waytogo.gif Good price on the fans
 
Yeah that's the best I could find. The only one I found in a junkyard was 125! Forget that. Junkyards really suck around here sometimes.
 
For fan switches I *personally* would stay away from adjustable ones.

Nothing inherently wrong with them, but why run one if you know the temperature range you want to operate in? (thermostat governs that anyway) I would guess no one goes in and changes it once it's set, since again, unless you change t-stat, you are wasting your time.

If you can handle "stock" temperatures, one out of a Buick Grand National, probably 1987, (check thirdgen.org for part numbers or recommendations) is one that comes on at a pretty low temperature, like 195*. 220* is a little bit too high IMO. 210* would be about perfect...you don't want to end up with the fans cycling all the time.

The secondary fan switch for a late 80's Camaro comes on at 240*, so obviously GM used many different ones.

Napa's "Echlin" catalog with the temp switches, oil pressure switches, etc., is INVALUABLE when looking for switches. Typically has the on temp, what threads it uses, and how it's wired, if more than one wire. If you go to Napa and say you want to browse through it, they will let you. Connectors get out of the wrecking yard.

You can wire them both up so they come on at once, but from my experience so far, in the "heat" we have, one fan is more than adequate, so I've got my secondary fan wired up as a backup...no reason to load the electrical system if it's not needed.

Those fans you are looking at, do they come with connectors? If they are "odd" connectors, you might have difficulty wiring them/keeping them connect if you can't easily get the right connectors. Same deal as the switches I suggested above...the pigtails usually cost $10-15 when the switch itself is usually $8-10.

For the relays I'd look under the hood of any late 80's early 90's GM product. The big oval shaped ones seem to be very stout, and the 80's/90's Camaro's and I think '88+ C/K trucks came with two of them on a bracket, which makes for easy mounting. Just cut the wires off and you've got the connectors for them as well, which are water resistant.

Don't know what tools you have access to, (I'm guessing more than I do heh) but I've got soldering stuff, some wiring, shrink wrap, and a little bit of experience wiring this stuff up if I can render any assistance.
 
I appreciate all the help and info. Wiring/electrical is kind of my expertise, so I've just been worrying about rounding up the parts. If the connectors turn out to be inconvenient, I'll just solder everything. I've got loads of wire, relays, and heat shrink already. Basically, I just need to figure out how to mount the fans and switch. I don't think I have any extra ports in my cooling system. /forums/images/graemlins/frown.gif I was thinking about switching waternecks to get one that has one of those plugs in it. Would that be the easiest way? Good place for the switch?
 
i just bought 2 from the junk yard for 35 bucks. you have to work the junkyard guys a little.

i usually say. " how much you want for this broken fan"

or " i was going to get a good one, but how much you want for this one?"

at least around here you can really bargain with them. look on car-part.com maybe?

good luck man!!
 
-START HIJACK-
In my accessory laden '89 (no winch, fancy stereo or off-road lights, yet) would I have to worry about amperage draw running the dual fans? Of course I ultimately wanna run a 140-200amp Power Master Alternator with dual optimas as I add other power hungry accessories, but I wanna know if my stock charging system is up to the task for now.
-END HIJACK-

Good price on the fans by-the-way!
And thanks for the link! /forums/images/graemlins/waytogo.gif
 
Well when you do what you ultimately want to do, then you would ultimately not have a problem. I'm just gonna run one fan off the temp switch, should be enough most of the time. If it starts to get hot when I'm really taxing things, I'll turn on the other one. I can't remember how many amps these fans draw. It is significant, but not rediculous. I'm gonna stay stock for the time being. I also figure that any time I am using both fans (the middle of a hot day) will not be the same time that I will be using headlights and the heater. I also have a sub/amp and power inverter, but won't ever need to have EVERYTHING on full blast at any given time. I think it'll be fine, but I wouldn't mind having a little extra assurance like one of those beefy alternators some time down the road.
 
I also have A/C ( /forums/images/graemlins/woot.gif ), a must in SC. So I'd want both fans on when running the A/C when its 100* outside. I think thats where I might have problems.
 
Yes you will have to upgrade your alternator. I am running a dual set up and a day after I installed the setup well I was stranded for a little while with no juice to start the truck. I am running a set of 2 14" fans I got from Advance for 40 bucks each plust another 10 bucks for the relay I wanted and took me less than an hour or so to get them wired up and installed. I have a hot wire wired in on mine that way if it gets too hot I flip a switch and they both come on. Last trail ride we had to stop for a while and let the other trucks cool down and I had no problems with cooling the whole trip.
 
Mines running a 78 amp alt. (stamped into the stock case)

With the headlights on high, and heater on high (HD heater, so will simulate the AC blower) and both fans running, I didn't see any problems.

Really depends how much your stock one puts out. I have a feeling a truck equipped like mine would originally would have come with a 40-something amp alt. Only thing you can really do is hook it all up, and see how your electrical system holds up. You should RARELY need both fans, except of course with AC, when both typically run.

As an addendum to my previous post, make sure that however you wire them, you can disconnect the fans from the wiring, or that the wiring allows you to pull them. On my fans once they are installed, pulling the connector off the motor is impossible, so a connector inline with the wiring makes removal much quicker and easier.

I love my weatherpack removal tool. /forums/images/graemlins/smile.gif Unlimited supply of connectors in the wrecking yard.
 
Your fuse panel will limit the amperage draw each component demands, blowing and breaking the circuit when it’s exceeded. Having plenty of amperage to pull from isn’t a problem as long as the stream that connects the source power to the junction (the terminals in the junction box, or fuse panel included) is up to the task. I'm sure the wiring from the alt. to the battery would need to be upgraded to a higher (numerically lower) gauge. With my understanding of electricity, a component needs a regulated voltage, but it will only pull a predetermined amount of amperage, regardless of how much is available. Of course, when a component malfunctions it can pull too much amperage, which is where a fuse comes in. If I were wiring all my additional accessories from a common junction (i.e. the stock fuse panel—which I wouldn’t), I would also upgrade the wire running to it as well to handle the additional amperage draw.
Having said that, you don’t want to create more electricity than you need. Not only is extra amperage dangerous, it also takes power from your engine to make all that extra amperage. That’s why I’m trying to get a feel for just how much these fans are gonna suck up.

Sorry… I just realized I was rambling…
Hope I didn’t put anyone to sleep.
 
ya i just wanted to make shure that if i put a 200amp alt in there im not gonna start frying stuff
 
That is a big, expensive alt.
You running some serious lights, winch, and or welder?
When I mentioned a 200amp alt, I was mostly dreaming. 140 should be plenty.
 
i work off the "better to have it and not need it than to need it and not have it" theroy, i like to buy stuff only once, like when the fron axel broke on my K5 i swiched to 1 ton, its just how i do stuff, But like i said if it fries stuff, im not gonna get it. I plan on a big stero and tv, PS2 and some other things, who says you cant ride the trails in style?? /forums/images/graemlins/histerical.gif
 
[ QUOTE ]
Mines running a 78 amp alt. (stamped into the stock case)

[/ QUOTE ]
mine being loaded with power windows, door lock, plow package, AC, I was hoping for a 90 amp. I guess I should look at it. Right now the headlights dim at idle with heater or AC on. Might have been replaced with a weaker one before I bought it.
 
When you wire up fans, you run them straight off the battery so you should end up with a "cushion" effect, or thats how I understand it anyways.

I never notice when the cooling fans come on, but I can watch the meter fluctuate when I hit the lights or heater, since that is drawn off the fuse panel.

Just run a fusible link from the battery to the relay, (fan wiring) and you will be fine. You can eliminate everything from the switching side of that wiring diagram without AC, except the 20A feed, and replace the ECM with whatever temp switch you want to run.

CONSTANT electrical draw (amp, heater, headlights, etc) will present more of a problem than things like the window motors, etc., but it's frustrating watching your voltage drop every time something is used. /forums/images/graemlins/smile.gif
 

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