theres several ways you can do this,and pull fans with a shroud mounted behind the radiator are far more efficient than pusher fans mounted in front of the radiator.
theres a huge difference in quality in electric fans that are available and
unless you have an upgraded alternator putting out serious amps you generally don,t get the best potential results
generally you hook up the fan to a positive battery lead thats only hot when the ignition switch is in the ON position, and the ground lead to a sensor that provides a ground connection at a set temp, generally in the 160F-180F range
air travels from the front of the car, toward the engine, thru the radiator where it absorbs and transfers heat from the radiators fins to the airflow,so fans behind radiator PULL those in front PUSH air toward the engine thru the radiator
https://www.jegs.com/i/JEGS/555/10308/10002/-1
ford remote starter relays can be used in many higher amp fan circuits
http://www.sears.com/craftsman-professional-dual-heat-soldering-gun/p-00927320000P
sensors generally get 12-14 ga anything that carries serious amps is probably 10 ga
and if its for a starter or alternator, or battery it is probably significantly heavier gauge, if your replacing a broken wire you can of course measure to find the old gauge size
http://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html
http://www.carid.com/dorman/radiator-fan-assembly.html
http://www.sunforceproducts.com/Support Section/Solar Panel & Charge Controllers/WireGaugeSelectionTable.pdf
http://www.summitracing.com/parts/HYP-4026/
viewtopic.php?f=57&t=574&p=736&hilit=relays#p736
and use a minimum of 12 ga copper wire to any electrical connection to a fan and 10 ga stranded wire is better as reducing resistance helps the fan run much more efficiently and draw a bit less amps, use too small a gauge and wire heats up adding resistance and its much more likely to fail.
relay
http://www.amazon.com/Absolute-RLS125-1 ... 436&sr=1-1
http://garage.grumpysperformance.co...-auto-elecrtrical-connectors.3105/#post-68805
http://garage.grumpysperformance.com/index.php?threads/setting-up-your-fuel-system.211/
https://www.amazon.com/VIOFO-Circui...ocphy=9012039&hvtargid=pla-586493323860&psc=1
as mentioned you could use a fuse power tap,, but.. Ive generally just found a source for a switched power with a multi meter,
or tapped off the battery terminal and added a manual switch...depends on what I was trying to accomplish, Ive generally run 10 ga wire to a relay is any significant amp loads were anticipated,
and soldered in a relay and fuse as required.
https://www.summitracing.com/parts/...MI-rP_gp6F5AIVyAOGCh3PWAB_EAQYASABEgKCevD_BwE
https://www.amazon.com/PACK-AMP-Wat...DJGHS4MHT2D&psc=1&refRID=SDXCB01E5DJGHS4MHT2D
https://www.amazon.com/Ehdis-Truck-...=B01KFKEHMG&psc=1&refRID=SDXCB01E5DJGHS4MHT2D
https://www.delcity.net/store/Weather-Pack-Assembled-Pigtails/p_810525.h_810527
http://www.summitracing.com/parts/HFM-ZFSWF/?rtype=10
http://www.summitracing.com/parts/FLX-298/
https://www.summitracing.com/parts/dak-pac-2750/reviews
most of the higher cost fans come with metal or occasionally plastic mount brackets
look closely, at the pictures , fans mounted without a full fan shroud are noticeably less effective at cooling
http://www.summitracing.com/parts/SUM-329725/
mounting a fan like these two examples without the correct fan shroud can cost you easily 30% or more in cooling efficiency, enough to make a very noticeable difference in engine temps
full shroud fans (below) are more efficient than a fan alone or partial shroud (above)
the shroud definitely helps cooling efficiency, SIGNIFICANTLY,if you don,t have one shop carefully and buy one , if your bucks down visit a salvage yard , measure carefully and buy one used they are commonly under $30
modify it as required to fit
\
http://www.summitracing.com/parts/HYP-4026/
http://www.summitracing.com/parts/HDA-3653/
http://www.summitracing.com/parts/SUM-381101/
http://www.v8s10.org/forum/viewtopic.php?f=46&t=20834
a fan shroud , used with a fan,tends to increase cooling efficiency
http://www.summitracing.com/parts/SUM-381010/?rtype=10
http://www.summitracing.com/parts/HFM-ZFCT/
http://www.carid.com/dorman/radiator-fan-assembly.html
when theres 8 of those cushion disks, logic says they are used as washers , placed between the ends of the mount ties (two on each connecting mount tie,four on each side, and on opposite sides of the radiator core)and used to protect the radiator fins to prevent the plastic ties from damaging the radiator fins
In many cases they come with 4 long plastic strips that resemble thin knitting needles the idea is for the pad to have that long thin plastic knitting needle, like support connector, pass thru the pads so they spread the clamp force, the pads are like large washers, the thin plastic strip passes thru the radiator between the radiator fins, and the fan brackets or those washer like pads have a one way clamp that grips the plastic connector in each corner holding it firmly (usually as a pull fan )to the inner radiator surface, (occasionally on the outer surface as a push fan)the excess is trimmed off with nippers, this makes for a fairly sturdy and easily mounted pull or push fan attachment
keep in mind that your alternator out-put should be high enough to allow the fans to operate at full speed any time they are turned on, its common for guys to add electric fans and find the electrical draw makes the fans operate at part speed until the engine rpms increase the alternator power output (YOULL NEED TO USE A MULTI METTER IN MANY CASES TO DIAGNOSE THIS)
RELATED INFO
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http://www.davebarton.com/pdf/coolingfandiagrams.pdf
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http://www.panteraplace.com/Tech%20Info ... od%20a.gif
http://944hybrids.forumotion.com/t1262- ... g-question
http://garage.grumpysperformance.com/index.php?threads/do-i-need-the-fan-shroud.13847/
10 ga wire should be all thats required
theres are 60 and 80 amp 12-14 volt relays with pig tails, or places to connect ring terminal connectors available, its common for high capacity fans to draw 35-40 amps at times, so using a 60-80 amp relay and the required minimum fuse amp rated circuit sure won,t hurt
obviously measuring the current draw would help here
http://www.ecutool.com/DT-337-Mini-ACDC ... _7294.html
viewtopic.php?f=70&t=3504&p=33365&hilit=solder+ring#p33365
http://www.ebay.com/itm/Heavy-Duty-Auto ... 0375347709
http://www.wiringproducts.com/contents/ ... relay.html
http://www.jegs.com/i/Derale/259/16738/10002/-1
http://www.technooutlet.com/viac025.htm ... 1b2166c62d
buy a quality fan heres what can happen if the blades on those metal engine driven fans get loose at high rpms
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