Fan wiring

[jesabbott]

Hi all
Quick question as I'm a newbie on electrics.

My 33 with Coyote 5.0 was started by someone else and they haven't, as far as I can tell, used the orange Coyote wire to run the cooling fan, the original fan fuse and relay are still in the fuse box. And to be honest I can't find a black box that looks like the one shown in the FFR Coyote installation manual, but maybe I'm blind!!
So I was intending to just go with the standard FFR Hot Rod wiring for the fan which shows the blue fan wire connected to the blue wire in the harness, and the ground from the fan connected to the sensor at the bottom of the radiator. Will that work?
Second question, in that set up, does the green thermo wire do anything, or do I just cut it back and tape it up?
FYI, the engine is running well, it settles down nicely after a few minutes and ticks over at I'm guessing around 900rpm, but at the moment the fan isn't coming on and although the wiring for the temp sensor seems to be correct I'm not getting any movement on the dial.
Sorry if I'm being stupid but as I said electrics aren't my strong point.
I suspect this may be the first of many electrical questions from me

[Nigel Allen]

Use the orange wire and let the Coyote ECU decide when it needs cooling.

1. Extend and connect the orange wire to the fan positive.
2. Connect other fan wire to ground.
3. Test for correct operation. Cut in is around 82C depending on coyote generation.
4. Crack a beer.

[edwardb]

First, I'm going to assume you're using the kit supplied Ron Francis wiring harness. Always a good idea to specify when asking a wiring question. You should also have the Chassis Wiring Harness manual. If you don't, it can be downloaded from Factory Five's instructions website. In the middle is a wiring diagram that's important to study and try to understand as best you can. Wiring is really pretty logical when you break it down. I will respond in two ways:

1. The standard Ron Francis wiring for the cooling fan is: Dk Blue Cooling fan +12V wire in the front harness to the positive terminal of the cooling fan. Negative (or ground) of the cooling fan to chassis ground. The front harness includes a black ground wire. The green thermo wire goes to your sensor. When the sensor reaches its rated temperature, it closes and the green wire goes to ground. This causes the cooling fan relay in the Ron Francis harness to energize (close) and +12V goes to the Dk Blue Cooling fan wire and the fan should run. Your method of connecting the fan ground to the sensor will not work.

2. With a Coyote, you can dispense with all of #1 and just connect the Coyote orange fan wire to the positive terminal of the cooling fan. Negative (or ground) of the cooling fan to chassis ground. When the Coyote PCM sees the appropriate temperature, it will put +12V on the orange fan wire and the cooling fan will run. Simple. As Nigel Allen described.

[jesabbott]

Thanks for your replies guys

[TxMike64]

2. With a Coyote, you can dispense with all of #1 and just connect the Coyote orange fan wire to the positive terminal of the cooling fan. Negative (or ground) of the cooling fan to chassis ground. When the Coyote PCM sees the appropriate temperature, it will put +12V on the orange fan wire and the cooling fan will run. Simple. As Nigel Allen described.

I hope that orange wire comes from a relay somewhere! You wouldn't want to run a cooling fan off ECM power. I don't know anything about the Coyote wiring harness (control pack?) but I do know the fan should be powered by battery voltage through a relay, which can be triggered by the ECM. Not saying yall are right or wrong, but just throwing out a word of caution....

[Mastertech5]

My LS3 ECM controls my fan directly. It has its own relay in the GM harness fuse block. I would imagine the Ford control Pack is the same way.

[Nigel Allen]

The PCM (power control module) does what it implies. It is a group of (fuse protected) relays, controlled by the ECM (engine control module).

The PCM effectively isolates the high current 'power' circuits away from the ECM.

In effect, the PCM is the black box that makes connecting up a Coyote simple, even for someone with elementary electrical knowledge. All of the PCM versions for the coyote come with an orange wire for connection to the fan.

Hope this helps.

Nige

[edwardb]

I hope that orange wire comes from a relay somewhere! You wouldn't want to run a cooling fan off ECM power. I don't know anything about the Coyote wiring harness (control pack?) but I do know the fan should be powered by battery voltage through a relay, which can be triggered by the ECM. Not saying yall are right or wrong, but just throwing out a word of caution....

To follow up what others have mentioned, the majority of the builders on here installing Coyotes are using the Ford Performance control pack. It includes the harness, power distribution box (PDB), PCM, O2 sensors, etc. The PCM via the Ford calibration determines when to turn the cooling fan on and off. But once triggered, it's powered through the PDB. Below is a screenshot of the PDB. The fan has a 50amp relay feed and a 70amp relay. The orange wire provided is 6 or 8 gauge (going from memory...). I think it's all up to the task. IMO the electrical engineers at Ford are pretty conservative with this crate motor setup. I suspect because they don't have any control over how/where it's installed.

[TxMike64]

Gotcha.... I was getting lost in alphabet soup (ECU, ECM, PCU, PCM, XYZ, ABC, OU812, LOL) and was not understanding where the orange wire was coming from.