aftermarket electric fans cause over heating

first off i have a 87 xj 4.0 i bought 2 i belive their 12'' fans their made by hayden i have 1 fan wired directly to ignition power so when i start it up it comes on the other i have wired into the stock temp switch (removed the manual fan of course) now it does ok on the freeway/highway but when im climbing a hill like going up wheelin around 25-30 mph or even on a trail it starts to over heat both fans are working i have a new head and radiator out of a 93 its the vented system new water pump belt nothing is blocking air in front i just dont understand why it gets hot are the fans not big enough? i was told when i bought them they would be more than enoguh because of the cfm the pull if i put the stock clutch fan back on and leave just 1 fan on and wired to the temp switch it does fine any help would be great thanks

I just run 2 rapidcool fans on the front pushing and the oem electric i removed the clutch fan. mine runs great on just the oem fan. i just turn on my push fans after crawling in hot temps for a while. are you sure your fans are pulling and not pushing? do they need a fan shroud? they should be able to handle it... burp the system maybe

if i remember correctly the biggest fan hayden makes only pushes 1300cfm which isn't even close to what you'd need. your 12" fans maybe pull 1000cfm. i'd have to check the book tomorrow though. you get what you pay for and hayden makes some alright stuff, but their fans are definitely lacking. go with a little better black magic/whatever and forget about it.

You need to have 2000+ cfm PLUS the stock A/C fan which puts out around the same too. You would have been better off using two 97+ A/C fans like shown on the site.
See my site for more fan installs.
www.go.jeep-xj.info

Gojeep said:

You need to have 2000+ cfm PLUS the stock A/C fan which puts out around the same too. You would have been better off using two 97+ A/C fans like shown on the site.
See my site for more fan installs.
www.go.jeep-xj.info

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Listen to this guy, he definately knows what he is talking about.

thanks for all the info guys