After a good two months running my new e-fan, I noticed it didn't come on
yesterday.

Checked:
70 Amp fuse feeding the Dakota Relay. Power is on both sides of relay. No power leaving the relay towards the fan when it should be running.

40 amp Rad fan fuse in PDC. Its good, but replaced it anyway.

PDC Rad Fan Relay. Couldn't figure out how to check it, so replaced it, no change.

There is no signal coming from the PDC to the Dakota Relay, which would seem to be the cause. I haven't gotten to check the fan itself, although I don't think its bad. I didn't want to start snipping wires yet, especially since I'm suddenly not getting power to the relay.

For those who followed my installation saga, you'll remember the stock wiring harness that powered the stock fan is what is now powering the Dakota relay. There is no 12 volts there. Any ideas what else could cause no power to be coming to the leads coming out of the PDC.

 

did you check for power to the fan when then a/c is on? it is the only way i know of to confirm that stock e-fan circuit is energized

if not you will have to get the FSM and check the signal pinouts to figure out where the signal comes from and see if that voltage path is intact, and if the pcm is sending the signal out on that pin to begin with

 

I did. With the engine running and A/C on, I measured first at the Dakota relay, no joy, and then disconnected the connector and measured the connector coming down from the PDC. 0VDC. I'm perplexed.

 

I went ahead and manually engaged the Dakota relay, confirmed it was sending voltage to the fan, and surprisingly the fan did not turn on. Looks like the fan is dead. I still don't know why I'm not getting power from the PDC to the relay, but I guess I'll tackle that when I get a replacement fan.

Anyone else that did the Taurus fan swap have one fail so soon? I don't drive this vehicle that often, so it really didn't run that much, although when it did it was always on the high speed.

 

My taurus fan (made by depo) is still working fine after 6 months or so.

 

Looking back over your install, question for you. Does your setup run the fan at different speeds (more or less power to speed up or slow down), or is it just using the low/high speed on the fan itself? I installed mine just using the high, and the thing is ridiculously loud. I'm considering running the replacement with just the low setting only. This time I'm going to wire the high and low wire up to the relay so that at least I can easily swap back to the high side if necessary.

 

Mine just uses the high and low speed. You could get yourself a single pole double throw switch for a few bucks to allow yourself to pick between the two speeds since you're not using a controller for it.

 

I went back and tested everything again. I must have been going to fast and missed something as the fan does indeed work. The relay works, there's just no signal coming to the relay to tell it to switch when its supposed to. I may have to go the controller route if I don't figure this thing out.

 

mine didn't have the stock e-fan so I don't know what to tell you there.

 

Yeah, you had no choice but to run the controller. I also may not have a choice.. Logically troubleshooting this is telling me that the power that should be going down the wiring harness from under the PDC is where the problem lies. Searching the archives I see a lot of recommendations to look for a bad fusible link in the circuit. That looks to be my next move.