89 240 overheating after electric fan installation

[L.D. 100]

I took out the old clutch fan and put in a 14" electric (the one in sticky on our own classified forum zerothread/172066) as well as a Hayden fan controller that is supposed to turn on at 185 degrees. well everything is doing its job untill I turn on the AC. The temp needle quickly starts rising... I havent let it go to see how hot it will get since i dont want to warp anything but it flies from the third line to the 4th line in a hurry, and then i turn the ac off and it comes back down. any ideas as to what I should look at? I know turning on the ac could increase temperatures a bit but my old fan never did it this drastically.

[slipnfall]

I presume you removed the stock AC fan? If so you've moved all of the active cooling to a single fan, and I have a feeling that 14" just isn't up to snuff. I'm not sure if anyone has ever actually measured it, but I'm pretty sure that clutch fan puts out way more than 1750cfm(roughly what that 14" is rated for). Also because your primary fan is now attached to the radiator, air isn't as free to enter the engine bay as it once way.

What type of climate are we talking about, and were you cruising, or sitting in traffic?

When's the last the radiator, fluid, thermostat, etc were changed? These things matter a great deal also.

'slip

[L.D. 100]

climate was around 80 F very humid, I was driving on regular city streets, stop and go.radiator was changed about 3 months ago but with a used one, fluid was changed at the time of the fan install since I also replaced both upper and lower radiator hoses, thermostat was changed about a week ago.so maybe not enough flow? the fan i got was advertised as 1800cfm...

[slipnfall]

I can't really say for certain: I mean does it feel like it's pulling as much air as the clutch fan? Perhaps it is an issue of the air coverage that the 14" provides... With the clutch fan you are sucking in air over the entire radiator by the negative pressure in the 'bay. With a small, concentrated fan like that, I doubt you are getting good radiator fin coverage. In general two smaller fans will cool better than a single higher CFM fan because you cover more surface area.

[L.D. 100]

ok so i have been driving the car the last couple of days and it seems ok on normal city driving to and from work but this is early in the morning and in the afternoon... so basically when its cool outside... well today i took it out mid-day when it was like 100degrees and got stuck in traffic for maybe 10 minutes.... temperature needle slowly crept up real high... then exited the freeway and it went down to normal once I started moving again... all in all im starting to think the single fan isnt sufficient... oh one interesting thing... I turned off the car (it was at normal operating temperature) and left the ignition on ON to keep the fan running... i return a few minutes later and the temperature needle is actually WAY higher... how does my engine turned off make more heat? this totally threw me off. i checked to make sure i didnt wire the fan backwards... pushing hot air at the radiator... but its correct... Im going to go tripple check right now again though... this is just too weird.thanks for the input btw

[torque2go]

same with me, im about to just put the stock clutch fan back on and say to hell with it. as soon as i put the ac on, it gets hot. that sucks !!