Electric fan control on Sd4x

[efloth]

Yes, I was interpreting that all wrong. The link below helped me understand the fundamentals of the output but both examples use an external transistor. is that what you mean by TTL Logic in your diagram?

https://www.microcontrollertips.com/wha ... drain-faq/

[efloth]

Finally figured it out! I'm using a pull-up resistor connected to the 5 volt reference pin. That is then connected to the ECU pin and the high input of the relay board. Once I implement the optocoupler circuit, I will send pictures and schematics.

[efloth]

Got the optocoupler circuit figured out. I was able to use a bunch of available pads/traces and solder it right in. Not my prettiest work but should get the job done safely. IC is Cosmo 1010. More to come.

Code: Select all

Float (Relay On)
91	01	46	B0	Pin 24			
91	02	46	B1	Pin 23			
91	04	46	B2	Pin 22			
91	08	46	B3	Pin 21			
91	10	46	B4	Pin 20			
91	20	46	B5	Pin 19			
91	40	46	B6	Pin 18			
91	80	46	B7	Pin 17


Drain (Relay Off)		
71	fe	46	B0	Pin 24			
71	fd	46	B1	Pin 23			
71	fb	46	B2	Pin 22			
71	f7	46	B3	Pin 21			
71	ef	46	B4	Pin 20			
71	df	46	B5	Pin 19			
71	bf	46	B6	Pin 18			
71	7f	46	B7	Pin 17			

[wwhite]

That’s awesome. That spare pad area you used is where the knock sensor chip would be on 6cyl sd47 hardware, fyi