Dealing with aftermarket radiator fan

[Geok]

2006 SE 2.4L with (what I discovered) is an aftermarket radiator fan. Gifted from father-in-law and he hardwired fan always on with ignition to dash fuse block. That was "unfused" and it melted part of the block, and fan is no longer working. Aftermarket fan is two wires (blue and black) and it works when grounded to black and blue hooked to battery power. I thought I could connect the factory fan connector on either the high or low side to the blue fan power lead and the black to black. One sided didn't work (neither on the high or low side) when I connected the aftermarket fan blue power line to the category radiator wiring harness. So, I decided to bridge the two sides (high and low of the factory connector) to the aftermarket radiator fan blue line and it worked with A/C on! I bought a Mopar connector and repined it with the aftermarket wires bridged, BUT, it seems like there is an issue with the load. The lines were sparking at the connector and seems like they instantly heated up.

Should I be shopping for a used radiator fan assembly ($300-400 range on eBay!)? Craft a fan switch (I have no idea what this aftermarket fan draws, fuse requirement, etc.)? Or try to devise an inline fuse on the ground wire like the factory fan assembly.

Some photos for reference below. As usual, thanks to anyone who can participate and help in this discussion.

 

[macleanflood]

Personally I'd ditch the electric fan...find yourself an OEM fan shroud at a junkyard or Davey's Jeep or Deep Jeep.

Following thread has all the parts listed for a fan clutch and fan...

https://wranglertjforum.com/threads/jeep-wrangler-tj-cooling-system-overhaul-faq.3397/

If not read a few posts or so down... someone was just playing with an electric fan...

-Mac

 

[Geok]

Personally I'd ditch the electric fan...find yourself an OEM fan shroud at a junkyard or Davey's Jeep or Deep Jeep.

Following thread has all the parts listed for a fan clutch and fan...

https://wranglertjforum.com/threads/jeep-wrangler-tj-cooling-system-overhaul-faq.3397/

If not read a few posts or so down... someone was just playing with an electric fan...

-Mac

Unfortunately (or fortunately if you swing toward electric fans), the OEM IS electric for the 2.4L. So, I don't know if there is a fan clutch conversion FROM electric.

 

[JustDandee]

Just confirming that your fan is a single speed and that the bridge is to pick up the signal from either pin to run the fan?

• Not sure if the wiring would backfeed up the unused side and cause a potential issue?
• If it is just a single wire fan and your getting hot maybe the amp load is more than the factory on the aftermarket fan and a relay is need. Use the signal from the plug but take it to heavier duty relay- not a lot of confidence in that as the true problem but a possible solution never the less
• Replace that fan with a new one maybe it has issues. Perhaps find a unit that has the two speeds - aftermarket, factory or junkyard donor such as a Taurus.

 

[Geok]

Just confirming that your fan is a single speed and that the bridge is to pick up the signal from either pin to run the fan?

• Not sure if the wiring would backfeed up the unused side and cause a potential issue?
• If it is just a single wire fan and your getting hot maybe the amp load is more than the factory on the aftermarket fan and a relay is need. Use the signal from the plug but take it to heavier duty relay- not a lot of confidence in that as the true problem but a possible solution never the less
• Replace that fan with a new one maybe it has issues. Perhaps find a unit that has the two speeds - aftermarket, factory or junkyard donor such as a Taurus.

Yes, single speed fan and yes on bridge to pick up high and low speed. I tried it one speed only, and it wouldn't work.
I have no idea on the back feed. Looking at a wiring diagram, the relay's are "on/off" switches and I don't believe it would pose an issue if both were on at the same time - but I'm not sure on this.
Was trying to use the factory relays, but I don't know the total amp pull of the aftermarket fan. It seems like the 40 amp fuse would blow if draw is greater than 40 amps? If it didn't blow, then something else is a weak link. I'm think the jumper cable I used may be inadequate (stranded copper 16#) or the connection was loose and arcing.
They don't make new OEM fans, but I can get a used one. They are just stupid expensive ($300-400) and no guarantee they will last. I was wondering if any of the other MOPAR 2.4L would have a similar unit? Like the PT Cruiser or Liberty?

 

[JustDandee]

According to the all knowing google…13 amps for a 16 gauge wire so that could be your heat source… need to go bigger. someone that is more multi meter savvy than me might know how to confirm the amp draw of the motor so you have that detail. A little curious why you don’t see a signal from both wires- wonder if you have a sender out also.

 

[Geok]

So I finally got around to working on the fan. Couldn't source a decent used fan, so I did the Dorman/Duralast 620-475 -2 speed fan replacement I read about on this site. The shroud I have was already drilled out for the aftermarket fan that was previously rigged up, so I just had to make the center hole a little larger for the Dorman fan motor replacement. It fit great! It has a three way plug that plugs right into the factory harness. I have two problems though,...
1) the harness I have left (after previous owner rigged up aftermarket fan - see above) is missing the in-line fuse portion, so Im going straight from fan to harness. I don't think this is an issue, but...
2) the fan does NOT come on with A/C (though my A/C isn't really working well right now, the clutch does come on - so should be electrically working as far as the Jeep is concerned) and I can't get it hot enough for the low speed fan to come on.

The fan did work and came on when I took the High speed and Low speed relays out and switched them? But it has not come on since then with both relays plugged in. I took a 9V battery to the leads on both repays and they worked, and tested them with about ~70 ohms.

I believe the coolant temp sensor works ok, since I get a gauge reading that goes to 190-200F when engine running and I don't have a check engine light.

I know this model fan motor has been used by other members, so I don't believe its a fan issue per se, but I'm not sure where to go from here?

 

[Geok]

Update on my progress to get the aftermarket fan to work. This is for the Dorman 620-475, which with some modifications to the fan shroud, fit really well. It also has the same OEM style connector.
1) Replaced fan motor and turned on A/C and no fan movement. Allowed vehicle to come up to temp (190-200F) and no fan.
2) Disconnected one of the fan relays and fan comes on.
3) Bridged the relay socket at pin 86 and 85 (competing the relay circuit) and the fan comes on. Did this for both high and low - so the cables to the fan from the relay switch are intact. By default, so is the fuse on the panel (though I checked this as well).
4) Checked all fuses on the fuse panel under the hood and in the vehicle behind the dash and all are fine ( a couple had the wrong amp fuse, and replaced them)
5) Tested each relay under load and got continuity between pin 30 (power) and 87 (fan switch) - so they work. Also had continuity between 30 and 87a without power, which is correct.
6) Unplugged coolant temp switch, which set off the fan. This is correct. It's a safety mechanism in case of switch failure. I had never received a coolant sensor failure warning, so I didn't think it was the sensor.
7) I checked the coolant temp switch connector and got continuity on the grounded side and 5v on the hot side with ignition on (this is normal).
8) I tested the resistance on the coolant temp switch and got nothing. I figured it must be a bad/broken coolant switch and replaced it.
9) After replacing the coolant switch, I started the Jeep, turned on AC and nothing. NO FAN.

SO, I'm kind of at a loss? Not sure where to go from here. The fan works when power is applied to it. The lines connecting to the fan are good. The relays work. There are no blown fuses (anywhere). The lines to the sensor work. The sensor is new AND I tested its resistance and it was around 1.8 ohms (normal).

Last two things I haven't accounted for are...
1) I do not have the original inline fuse portion of the harness. The original harness comes from the fuse panel, has a secondary harness with an inline 30amp fuse ONLY on the ground, and that connects to the fan. Since that fuse is usually intact, and the fan runs with it intact, I don't think that's the issue.
2) My A/C needs charging/repair. The clutch cycles on, so electrically its working, which should make the radiator fan come on.
3) Maybe I have an ECM issue? I hate this one, because the vehicle runs fine and hasn't had any codes pop up that I wasn't expecting (it gave a coolant system code when I disconnected the relay while running - which is what its supposed to do, and it reset fine).

Anybody else with a suggestion? If I could get the fan to cycle normally, then the Dorman fan is a ~$70 NEW replacement for the 2.4L TJ radiator fans (that are NLA). I know others have used this fan, since I got the idea on this forum. Anybody run into any issues?

 

[Geok]

So, in a nutshell - I just needed some refrigerant to get the radiator fan to kick on low.
Hopefully that saves someone some aggravation if they are struggling to figure out why the low speed fan will not kick on - it may be because you have low refrigerant.

On the bright side, I can definitively say the Dorman 620-475 radiator fan motor works great. I got it off Amazon for ~$70. Just disconnected the motor and blade from the new shroud, cut an opening in the existing shroud to fit the new motor, screwed it together, installed and plugged.

I changed the coolant temp sensor as well in the process, but the whole thing may have worked fine had I had adequate refrigerant to begin with.

I don't know if a moderator has a running link of aftermarket replacement parts for NLA, but if they do, this one definitely belongs there for 2003-2006 TJs with factory electric fans.