98 Gr. Caravan Radiator Fan Runs CONSTANTLY!

whitt38460 · #1 10-23-2005, 01:30 PM

Can anyone help? My father's 1998 Dodge Grand Caravan SE radiator fan runs constantly - even with the ignition off. He has to disengage the battery for the fan to quit running - what might be wrong? Can you give us some suggestions to try?

coalminer · #2 10-23-2005, 02:09 PM

More than likely your cooling fan relay is stuck in the closed position, under the hood there should be a box with several relays, on the inside cover it will have a diagram, pull out the relay for the cooling fan and it should shut off.

whitt38460 · #3 10-23-2005, 02:43 PM

Quote:

Originally Posted by coalminer

More than likely your cooling fan relay is stuck in the closed position, under the hood there should be a box with several relays, on the inside cover it will have a diagram, pull out the relay for the cooling fan and it should shut off.

Thanks for the quick reply. We have already looked in that box with all the relays in it and did not find the cooling fan relay - is there another place that the relay may be located or do you think we may have just overlooked it? Thanks again for your help.

coalminer · #4 10-23-2005, 02:49 PM

Quote:

Originally Posted by whitt38460

Thanks for the quick reply. We have already looked in that box with all the relays in it and did not find the cooling fan relay - is there another place that the relay may be located or do you think we may have just overlooked it? Thanks again for your help.

Its got to be under the hood somewhere, I know in my 95, there is no box under the hood, but there are several relays that are along the side by the battery. The fuel pump relay and I believe the auto shutdown relay are all in the same location. The fan relay should stick out in that the wires going to it should be a larger gauge than the other relays.

Hope this helps!!!!

KManiac · #5 10-23-2005, 06:16 PM

Hello All:

Below is my responce to a similar thread in the forum called "Cooling Fans". This reply was posted back on August 6. 2005. The answer to your questions are included in my post. I highly suggest searching these forums for similar topics when you do have a question. You may find the answer is already here, just in the past. Anyway, here is my old reply:

I encountered the same problem with my van, a 1998 Chrysler Town & Country LX AWD.

My wife came home the other night and announced that the fans weren't shutting off in the van. I found both radiator fans running at full speed, even though the ignition was turned off. I stopped them by pulling the rad fan 40 amp fuse (in the relay/fuse panel, under the hood). I reconnected the fuse within 30 seconds and the fans restarted. I pulled the fuse again and waited 15 minutes. This time, I got sparks at the fuse terminals when pushed in the fuse, but no fan restart. I figured that whatever relay had stuck on had shut off.

The next day, I get a frantic call from my wife saying the van had overheated, with she and the kids were stuck downtown at a gas station. I rescued her with a second car and proceeded to trouble shoot the problem. There were no visable leaks, the overflow tank was FULL and she had driven the car about 25 miles before it overheated on this 90 degree afternoon, in traffic with the A/C on. After sitting for a half hour, I found the temperature gauge reading in the middle, normal for this car. I started it up, turned the heater full blast and drove the car home. The temperature gauge stayed at normal the entire trip. Once I got home, I turned on the A/C and let the car idle in the driveway. The engine began to overheat and I noticed the radiator fans were not running. Given this set of circumstances, I deduced that the radiator fan relay was bad and needed replacement.

The rad fan relay is not, I repeat, not in the fuse/relay box. It is mounted on the driver's side radiator support in the engine compartment. You need to remove the entire air filter assembly to expose the relay. The part number on my old relay was 04707286AD. The dealer quoted me $70 for an upgraded replacement identifed with the last two letters AG. The local autoparts store quoted me $45. I bought the less expensive relay, which had the same part number, except the last two letters were AF. I installed the new relay and now the fans work again.

I hope others can learn from my experience.

Mailt4 · #6 10-23-2005, 06:27 PM

This Relay is nothing like you've ever seen before, it is a Pause Width Modulated Relay, it turns the Fans on in mitiple speeds, this Relay is not available at your autopart stores, Dealers only, it run about $80.00 around my hood, it is not in your Relay Box or look like your 4/5 pin Relay.
The Relay is located beside the Radiator on the Drive Side, behide Air filter Housing, it bolted in the radiator support , one connector/4 wires....

Mai
**

Mailt4 · #7 10-23-2005, 06:30 PM

Looks like KManiac got to you first

Mai
**

Dakaty · #8 10-23-2005, 11:24 PM

The relay is available at O'Reilly auto parts. I bought one today. It cost just under $60.00 including tax.

The parts guy did not find the relay in the computer. He looked in their electronics book and found it. The relay has the same part number as the factory relay stamped on it.

OReilly part number BWD R4736

HTH

John315 · #9 07-28-2007, 05:00 PM

KManiac - You saved me a ton of time with your response. I had the exact problem you discribed with the fans not shutting down. I spent a day pulling the fuse before getting a chance to look for some information.

What had me stumped is that I had just replaced the clockswitch in the steering wheel, and after test driving the fans won't shut off. I was fairly sure there was no link between the two, but the timing was ironic. Anyway, I read your post above and went out a did some checking. I pulled the fuse one more time and plugged it back in, both fans died.

I ordered the part from Rock Auto (about $40 incl shipping) and replaced it today. Took about 15 minutes to complete the fix. Had you not provided such good advice, I'm sure I would have spent the better part of a day just looking for the problem.

Thanks again!

mishalah · #10 08-01-2007, 07:22 PM

FYI: I found the relay also available at Pep Boys and AutoZone for $57 and $60 respectively. AZ had another one listed for $40, but it had to be ordered.

My fans did the opposite and wouldn't come on at all. Last year I went through the same process (KMANIAC again being a big help), but it turned out to be the temp sender unit. Maybe a good bet is to replace them both at the same time. I think the TSU was only about $15-20.

KManiac · #11 08-01-2007, 08:56 PM

Wow!! I'm glad someone appreciates my advice. "Thank you" and "your welcome" to all.

mishalah · #12 08-02-2007, 08:58 AM

Quote:

Originally Posted by KManiac

Wow!! I'm glad someone appreciates my advice. "Thank you" and "your welcome" to all.

You deserve the thanks.

I see you're a serious 300K guy. My dad had a '57 300(D?) that he'd scare the pants offa me flying up and down those steep hills in San Francisco. It was such a beast, but gave me a love for the Mopars.

In high school my friends (and their parents) were all competing for muscle car supremacy. Besides the home made hotrods, 409 SS Impalas, Buick Gran Sports, GTOs, and a few Fords were the non-Mopar favorites. Then two kids went out and bought '64 Max Wedge Plymouth Sport Fury coupes. Identical black with red/black interiors.

I was impressed by those, but my favorite was one of my classmate's father's '64 300K. It was a beautiful black hardtop with all white interior. I think it "only" had the 413 with dual 4bbls, but it had that beefy 4 speed with the Hurst shifter sticking out of the console. It wasn't the fastest car in town, but is sure was the classiest. I have never seen one since then. I'd like to hope it survived.

thub · #13 07-19-2009, 05:26 PM

Kmaniac thank you also, I had the exact same problem and your post
was perfect for me and I had the problem solved in no time. Just a few additional items. My relay part # was 04707286AF: AI and AB also qualify.
The relay is about 1 1/2" by 1 1/2" square. I drove my van up on ramps
and had easy access to it. It was right below the air filter housing, drivers
side. Had it out in 10 minutes, 2 screws. I paid $40 at Auto Zone, their
cross part # was MT1386, and they couldn't find it at first because it's
an A/C relay as well and it was in their A/C area. Mine is a 98 Caravan
but there was a note that it worked for 99 and later as well, There was
also a note to be sure that the relay fits flat against the underlying metal
panel with no air gap for proper heat transfer. Improperly mounted relays
will fail and cause the engine to overheat.

RIP · #14 07-20-2009, 02:14 PM

thub - Would have been a better idea to send Kmaniac a personnal message rather that open a 2 year old thread but, I'd bet you don't know how. Just click his name and then click "Send a private message". Welcome to the forum and thanks for posting your experience.

For all in doubt here's a pic of a cooling fan relay from the gallery. It's from a 97 but all should look similar: http://files.automotiveforums.com/ga...cat=998&page=1

cnj310 · #15 06-28-2010, 12:37 PM

KManiac, thank you for the information. Advance Autoparts had the part for $49. It was located exactly where you said it was (front lower driver side of radiator attached to the chassis) held in by (2) 8mm screws. My the fan on my 97 grand caravan ran for 30 minutes before I had to disconnect my battery. The next day the fan wouldn't run at all. But we're all better now.

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