electric fan air flow direction?
Thread Starter
Seasoned Member
Joined: Sep 2013
Posts: 362
Likes: 2
From: LI, NY
Year: 2000
Model: Cherokee
Engine: 4.0
Does the electric fan on a 2000 4.0 suck the air through like the mechanical fan or does it blow the air out through the grille? Mines been running a bit hot and I just noticed that its blowing out, opposite of what the other fan does. Is this right?
CF Veteran
Joined: Sep 2010
Posts: 12,692
Likes: 6
From: Mercer County, NJ
Year: 2001
Model: Cherokee
Engine: 4.0L I6 HO
Mines sucks air in and I dont have overheat issue
Beach Bum
Joined: Jul 2011
Posts: 6,123
Likes: 22
From: Cape Hatteras, North Carolina
Year: 2000 WJ
Model: Grand Cherokee
Engine: 4.0
The e-fan should draw air into the engine bay, just like mechanical fan. Inspect the harness plug that it is plugged in properly. The factory plugs usually can only connect the proper way, unless they are forced.
Thread Starter
Seasoned Member
Joined: Sep 2013
Posts: 362
Likes: 2
From: LI, NY
Year: 2000
Model: Cherokee
Engine: 4.0
This is what I thought too. It was bizarre. Im standing in front of the jeep and I feel all this heat coming off the grille. The pass side of the grille I can feel it drawing the air past my hand but on the drivers side Its blowing hot air out at me while the e-fan is on. Is there any way that the computer is reversing the fan rotation? I replaced this fan about a year ago and Im pretty certain that it was operating properly at the time.
Beach Bum
Joined: Jul 2011
Posts: 6,123
Likes: 22
From: Cape Hatteras, North Carolina
Year: 2000 WJ
Model: Grand Cherokee
Engine: 4.0
The computer will not reverse the e-fan. My guess is, it is installed backwards or is the wrong unit.
Look at which direction it turns and see if that matches the correct rotation of fan blades. This will determine if it is running in reverse or unit is backwards.
Also check harness plug for proper orientation.
Look at which direction it turns and see if that matches the correct rotation of fan blades. This will determine if it is running in reverse or unit is backwards.
Also check harness plug for proper orientation.
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The computer will not reverse the e-fan. My guess is, it is installed backwards or is the wrong unit.
Look at which direction it turns and see if that matches the correct rotation of fan blades. This will determine if it is running in reverse or unit is backwards.
Also check harness plug for proper orientation.
Look at which direction it turns and see if that matches the correct rotation of fan blades. This will determine if it is running in reverse or unit is backwards.
Also check harness plug for proper orientation.
Steve is right on with this. A lot of electric fans are multi application and the connector terminal polarity may have been installed into the harness plug housing backwards from yours from the maker and be meant for a different application. These can be carefully removed and switched around with a small pick.
Thread Starter
Seasoned Member
Joined: Sep 2013
Posts: 362
Likes: 2
From: LI, NY
Year: 2000
Model: Cherokee
Engine: 4.0
So, Ive confirmed that the fan is running backwards and blowing air into the radiator instead of pulling it through. The plug can only go on one way. Ive removed wires from connectors before but mostly in older gm vehicles. I have no clue how to disassemble this one. Theres a red plastic part inside the black outer connector that I guess I need to remove so I can get the induvidual metal connectors out of it. There are 3 holes in the red plastic plug. 2 of them are for the metal connectors but the 3rd is empty. Maybe its a key of some sort? Any ideas how to get it apart without breaking the connector open? I could always cut and reverse the wires as a last resort.
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
Confirm the wire connections at the connector before tearing it apart.
Here's a pin out of the Rad Fan connector (body harness end). The Light Blue wire is power from the Rad Fan Relay.
Bubba may have spliced in a new connector and got his wires crossed.
Using a voltmeter or test light, test for battery voltage at pin 1 of the connector.
Here's a pin out of the Rad Fan connector (body harness end). The Light Blue wire is power from the Rad Fan Relay.
Bubba may have spliced in a new connector and got his wires crossed.
Using a voltmeter or test light, test for battery voltage at pin 1 of the connector.
Confirm the wire connections at the connector before tearing it apart.
Here's a pin out of the Rad Fan connector (body harness end). The Light Blue wire is power from the Rad Fan Relay.
Bubba may have spliced in a new connector and got his wires crossed.
Using a voltmeter or test light, test for battery voltage at pin 1 of the connector.

Here's a pin out of the Rad Fan connector (body harness end). The Light Blue wire is power from the Rad Fan Relay.
Bubba may have spliced in a new connector and got his wires crossed.
Using a voltmeter or test light, test for battery voltage at pin 1 of the connector.

Ken is wise with this suggestion...double check your pin out before taking it apart. If it turns out they do need to be switched look down into the holes where the terminal connectors are in the plug housing. You will see each has a little spring "Catch" sticking from the outside of the terminals.
Please disregard the instructions I gave here. Wrong plug type.
Last edited by Bugout4x4; Oct 31, 2015 at 06:54 PM.
Please disregard the previous instructions I gave you about how these plugs come apart. I was thinking of a different plug type than what you have, I was thinking of the ones on my Dodge Ram.
This is a male plug on the wires coming from the the fan right?
This is a male plug on the wires coming from the the fan right?
Thread Starter
Seasoned Member
Joined: Sep 2013
Posts: 362
Likes: 2
From: LI, NY
Year: 2000
Model: Cherokee
Engine: 4.0
It makes me wonder the same thing. I checked the pinout and it is correct coming from the harness. However, on the fan side of the plug there is a heavy gauge blue wire and a lighter black one. The plug has the black wire getting the power and the heavy blue one as ground. Backwards. I ended up cutting the wires on the fan side and switching, soldering, taping it up. It spins correctly now, sucking much air. This was a brand new replacement I bought off amazon. I wonder how many others are having heat soak problems due to this same issue. Its worth a look I'd say. Since I dont think I'll be seeing any more 75+ degree days here I will have to wait for spring to be sure.



