Ford Windstar E-Fan Wiring Question

[dayj1]

Originally Posted by First c10

I have a question regards to diagram 2 and the last diagram. Aren't they the same but with only one 47 ohm resister and coil?

If I understand right, you're asking about the difference between the last and the second to last diagram. If so, the last one does not control the low speed fan relay at all. It allows you to "leave out" two diodes and a resistor and a couple of wires.

Originally Posted by First c10

don't you have to have the low speed relay grounded by the PCM to get high speed ground to work?

No. The 3 relay setup has some redundancy built in. At least one fan will run at full speed if any of the relays fail or if only one of the control lines is working.