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Old 08-12-2013, 10:48 AM   #1
nosfed2
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From Clutch fan to Mark Viii fan now a/c not blowing as cold?

So I have been waitng on my controller from DC controlls and it showed up saturday and me and my uncle installed the markviii fan and the controller and the engin temps stays at 180 but the a/c only gets down to 50 deg in the center vent where before with the old clutch fan it was at 40 deg on the same day? We wired it up so when the A/C clutch is engaged it turns the fan on at 50% it is on and blowing but the flow in the grill doesnt seem as strong?

Last edited by nosfed2; 08-12-2013 at 10:55 AM.
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Old 08-12-2013, 11:21 AM   #2
Ziegelsteinfaust
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

Do you have the fan wired to high speed?

You may have it wired on low.
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Old 08-12-2013, 12:34 PM   #3
nosfed2
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

yeah its on high I tested it before the install. I could install another fan on the condensor also?
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Old 08-12-2013, 02:54 PM   #4
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

Is the fan in some type of shroud that covers the whole radiator, or at least almost the whole radiator? If not, this could be the issue. As far as adding a pusher fan in front, I wouldn't. I have the same fan, and I also have pushers on the front. The pushers currently have the relay unplugged to them, as the a/c actually works better without them on. Reason being, I have my Mark VIII in a stock big block shroud, and due to it being in the shroud, it pulls air from the entire radiator, and the entire condenser. With the pushers on, it causes the condenser only to be cooled in the areas where the pushers are, rather than the entire condenser.
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Old 08-12-2013, 03:10 PM   #5
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

It is still in the stock shroud mounted in the middle of the radiator it is covering over 75% of the radiator. but there is a gap inbetween the radiator and the condensor? I was hoping this was gonna cool the motor better and inprove the a/c cooling also. I did have a 7 blade h/d clutch fan. I am going to go home tonight and see if the fan is comming on 100% or not...I just dont like how the fan cycles on and off with the clutch it does it quite offten?
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Old 08-12-2013, 05:32 PM   #6
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

I would install a Mark VIII this way. http://www.off-road.com/trucks-4x4/p...oject1580.html
If you plan to only run low speed (80%), you should block off the gap between radiator and condensor. You can trim pieces to fit the area from '90 model year trucks.
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Old 08-12-2013, 09:38 PM   #7
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

You need the fan on high speed with the ac on. I think you said you are running 50%?
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Old 08-13-2013, 12:26 AM   #8
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

Well went home tonight and down to the garage and the fan is coming on 100% but it still is not moving as much air as the clutch fan so I put it back on tonight and the a/c is back to blowing 40 Deg and the engine temp is 190 again....Idk I may hook up a electric fan on the condenser and keep the clutch fan also just so I can use the fan controller...it really sucks because I bought a 140 amp alternator $154.00 and the controller $200.00 and the fan from a junk yard $18.00 and other little stuff so I am about $400.00 bucks into it but if I cant use my a/c it really isn't worth it...oh and the way I had it set up way exactly like the site that (gchemist) posted so I am lost It was blowing pretty hard but the clutch fan blows like a beast. I took a piece of card board and put it in the grill with the Mark viii fan wire straight to the battery (High side) and it wouldn't hold it to the grill but the clutch fan wont let it go??? Thanks for the help guys... 2 steps forward 5 steps backwards
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Old 08-13-2013, 08:32 AM   #9
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

Something is not right...I never heard of a clutch fan that blew more than that fan on high.
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Old 08-14-2013, 12:36 PM   #10
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

Quote:
Originally Posted by Rich84 View Post
Something is not right...I never heard of a clutch fan that blew more than that fan on high.
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Agreed.
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Old 08-14-2013, 03:09 PM   #11
nosfed2
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

It has 3 wires and i am using the Black (Ground) and the brown with a orange strip (High) the other is Blue (Low) and the controller is a Delta Current Controller or DCC. The controller is working fine. What i dont get is everybody says after 35 mph the fans dont really keep it cool but with the electric fan even over 35 mph the a/c was still not as cold but with the Clutch fan it was?
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Old 08-14-2013, 11:55 AM   #12
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

Is the fan a three wire fan? What type of controller are you using?
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Old 08-14-2013, 03:35 PM   #13
Rich84
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

Maybe the junkyard fan is no good..nothing blows like a ford fan...lol.
I know many people that don't even use the high speed.
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Old 08-14-2013, 05:22 PM   #14
nosfed2
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

I have 3 of these fans and when i pulled it out I hooked all 3 up to see if it was not spinning as fast as the others and they all where spinning fast as all hell?
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Old 08-14-2013, 06:31 PM   #15
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

I'm sure it's not the case, but perhaps the wires are somehow switched? Did you try using the blue with the black, and see if it moves more air?
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Old 08-14-2013, 09:00 PM   #16
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Re: From Clutch fan to Mark Viii fan now a/c not blowing as cold?

Decode your fan part number here: http://forums.tccoa.com/showthread.php?t=136722
Your fan may be a unique one that requires a controller for speed not just activation.

True fan CFM tests: http://forums.corvetteforum.com/c3-t...pal-duals.html
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Last edited by gchemist; 08-14-2013 at 09:06 PM.
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