Wiring 350z fans
Any update on how to hardwire the fans. I would like to maintain the factory logic but also have a switch to bypass the cpu and connect the two dans on high speed. I was reading that you need to send power to the blue and green wires and attach them together for high speed, is this correct, is the rev-up sam wire colors for the fans? Pls help!!
Gotta understand how the cooling system, how the electronics work, and how the logic works.
around 190degrees the low speed fan circuit turns on. It’s 12volts (obviously) and I dont know the exact current but I suspect it somewhat larged based on the B/W wire size. Then around 210degrees the high speed fan circuit kicks on in-conjunction with the low speed fan.
So when the logic recieves input from the ECU that the temps warrant fans (and how I understand it) it low sides throught the IPDM and activates both Fan Relay 1 and Fan Relay 3. The IPDM triggers both relays and both high speed fan options and low speed fan options. Both high speed fans and low speed fans are getting 12volts.
The key here is that the low speed fans are permently grounded … so as soon as Relay 1 and Relay 3 are trigger they ground-out and the low speed fans activate.
The high speed fans rely on Fan Relay Number 2 to receive logic and low-side ground out which activates the two grounds for the high speed fan operation (sorta confusing). I suspect the high speed fans draw a slightly smaller amount of current based on the B/R wire gauge (althought it only feeds those two high speed fan circuits).
answer your question -
Your best bet is to wire them how poeple wire fuel pump relays.
Use one of the low speed 12volt power line as your trigger on the relay … and then also connect a manual operated switch (12v high side) to the same pin of the relay. When the ECU determine that engine coolant temps are over 190 degrees it will activate the relay. If you would like to manually turn on the fans you can with the switch.
around 190degrees the low speed fan circuit turns on. It’s 12volts (obviously) and I dont know the exact current but I suspect it somewhat larged based on the B/W wire size. Then around 210degrees the high speed fan circuit kicks on in-conjunction with the low speed fan.
So when the logic recieves input from the ECU that the temps warrant fans (and how I understand it) it low sides throught the IPDM and activates both Fan Relay 1 and Fan Relay 3. The IPDM triggers both relays and both high speed fan options and low speed fan options. Both high speed fans and low speed fans are getting 12volts.
The key here is that the low speed fans are permently grounded … so as soon as Relay 1 and Relay 3 are trigger they ground-out and the low speed fans activate.
The high speed fans rely on Fan Relay Number 2 to receive logic and low-side ground out which activates the two grounds for the high speed fan operation (sorta confusing). I suspect the high speed fans draw a slightly smaller amount of current based on the B/R wire gauge (althought it only feeds those two high speed fan circuits).
answer your question -
Your best bet is to wire them how poeple wire fuel pump relays.
Use one of the low speed 12volt power line as your trigger on the relay … and then also connect a manual operated switch (12v high side) to the same pin of the relay. When the ECU determine that engine coolant temps are over 190 degrees it will activate the relay. If you would like to manually turn on the fans you can with the switch.
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satinwhite_z33
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Aug 17, 2022 12:40 PM