D2 AC Condensor Fan

rmuller

Well-known member
Apr 28, 2004
4,452
1
Northern NJ
www.njlr.org
So while investigating a slightly high temperature the other day, I found that the 40amp fuse going to the fan condensor was blown.. So I replaced the fuse, and since from what I read, the fan isn't supposed to kick in unless the ambient temperature is 82* F, I hot wired the relay to try it out, and it blew the fuse again. So the next thing I wanted to check was the fan itself, so I ran power directly to the fan, and it went on without a problem. I then checked the plug that goes to the fan, and both sides of it were grounded, making me think that there was a short somewhere.. I inspected the wiring harness from the plug to the fusebox and there are no visible breaks in the wires or anything... Other than thinking the fusebox itself may be bad, I'm at a loss as to what else it could be... any ideas?
 

JohnB

Well-known member
Oct 18, 2007
2,291
11
Oregon
Since the bcu controls the fan relay and the relay is negative activated I would think you have a bad fan relay.
I ran a relay on my fan that gets activated by the ac pump turning on. Inline fuse attached to the battery. I bridged the plug so the BCU can still intervine to do its business if need be.
 

Big D

Well-known member
Mar 14, 2011
126
0
Canada
Looks like this seems to be common. I ran into the same problem. Brand new fan. New fuse, changed relay, took fuse box apart, checked wires and power and ground are good from fuse box to fan but still no work...

What gives?
 

Big D

Well-known member
Mar 14, 2011
126
0
Canada
Ooops...forgot to mention that when I try and triggr it with the hawkeye it says its unavailable. Any ideas?
 

The Fourth Amigo

Well-known member
Apr 20, 2009
641
2
Electric cooling fan switching points:
For A/C system:

On When Vehicle speed is 80Km/h or less and ambient temperature 28 C or more

Off When vehicle speed increases 100Km/h or ambient temperature decreases
to 25 C

For engine cooling during normal running

On 100 C

Off 94.5



For engine cooling at ignition off

On Within 10 sec of ignition off, intake air temperature 60 C or more
Coolant temperature 110 C or more

Off After 10 minutes if engine coolant temperature decreases to 100 C


This info helped me troubleshoot my fan troubles


Also, my Hawkeye won't activate the fan either. Maybe the problem will be corrected if I get the software update.
 
Last edited:

flyfisher11

Well-known member
May 25, 2005
8,676
2
61
Wolf Laurel NC
Ryan,

FWIW I got rid of the whole damned circuit on mine and went with an aftermarket (Kenlow) fan controller. I got another connector for the condensor fan from Marty and wired it to my controller. I then set the auto temp where I wanted it, ran a manual switch in the cabin and also a manual override switch to override everything and shut the fan off if need be (water fording). Works like a champ!

Cheers,

Mike
 

adriatic04

Well-known member
Mar 22, 2007
2,506
2
cleveland, oh
Ryan,

any luck here? Mine keeps blowing the 40a fuse in the engine bay. I need this fan to run, from what I recall it helps with at least 4-5 degrees in temp. I cannot find any short, everything looks clean. I have been seeing 208 after highway driving and at a stop, I am used to seeing 201-203 and I have a feeling this fan is the culprit.

Mike,

I am not the most electrically inclined individual. Can you reference me to some parts online you used to put this setup together? I am interested to know more but this might be more than I can handle.
 

RoverbyProxy

Well-known member
Apr 21, 2011
288
0
Michigan
You need to check the current draw of the fan. Seems to me that if the fuse is blowing when the fan activates then you have a bad fan.
 

super88

Well-known member
Nov 28, 2004
94
0
Mile High City
Or get yourself a brand new motor: AC Delco - 1580341 / NAPA- BK 6552105 / Advance Auto - 35110. $70-$100.

Direct replacement, just verify polarity/fan direction. Info provided by another dweb poster (actually The Fourth Amigo, IIRC). I'm about to do the same.
 
Last edited:

super88

Well-known member
Nov 28, 2004
94
0
Mile High City
adriatic04,

I haven't dug in to the project just yet, but I'll tell you my rudimentary plan, as it may help you. If I've over-simplified, I apologize. But you seem a bit intimidated and I doubt it will be too tough.

1) Remove the OEM assembly
2) Cut the connector plug off the old motor, leaving enough wire on the connector to work with (~2"-3"). This is your OEM "pigtail"
3) Strip back some insulation on each of the leads still attached to the old motor and apply 12V to determine the proper polarity to make it spin in the correct direction. You have a 50/50 shot at getting it right on the first try!
4) Tag the two wires on the OEM pigtail as +12 and -12 based on the data you gathered in step 3.
5) Install the new motor in the fan assembly
6) Apply 12V to the new motor to determine the proper polarity to make it spin correctly
7) Tag the two wires on the new motor as +12 and -12 based on the data gathered in step 6
8) Solder the OEM connector to the new motor as appropriate to marry the +12s and -12s to one another.

If you can wait a couple of more days, I'll post my swap and include some pics.

Cheers,
Gavin
 

super88

Well-known member
Nov 28, 2004
94
0
Mile High City
Well, it wasn't exactly smooth sailing like I had expected. The swap was easy. I'll work on a write up.

Unfortunately I waited a little too long before getting around to the swap last night. So, my first piece of advice: if you're ac condenser fan is starting to shit the bed, unplug it, or pull the fuse or relay or something. Turns out the positive lead from the fusebox (black w/ brown on my truck) and the ground (black) decided to become best friends. They melted together right under the battery tray. :banghead:

So after I got everything hooked up I blew a couple of fuses. I scratched my head... I checked the relay, no problems. I pulled the connector apart and powered the fan directly from the battery again, no problems. I checked the connector from the vehicle side and it was grounding out on both terminals. That's when I realized I had a problem. So I ripped out the battery tray and fusebox, tore all the wire looming and electrical tape away and found a 2" section that was a melted mess. So I just clipped both ends and ran a new pair of wires, leaving about 6" of the original wires at each end and splicing in-between.

Cheers,
Gavin