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Old 05-20-2013, 12:06 PM   #4
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This is the wiring diagram out of the Altima.

Notice it uses three (3) relays: One for the low speed (Relay 3) and two for the high speed.

On the high speed relays, Relay 1 is for power and Relay 2 is for ground. This tells me the Ground Wiring of the High Speed motor setting should NOT be grounded when using the Low Speed setting of the motor.

Also, notice that Fans 1 and 2 get their power from separate fused circuits, so if one fuse fails a fan can continue to keep the engine cool.

For those without A/C (like me), the High Speed motor is probably unnecessary; however, a toggle switch could be mounted inside the cab to serve as extra cooling during an emergency.

When you get time, could you update your 3rd post?

On the temperature sensor:
  • Why did you selected it?
  • Does it bolt in directly with no modifications?
  • Does it work with the D21 ECU?
On the relay:
  • What part number is it?
  • Is it a double pole double throw?
  • Where will it be mounted?
I am sure you plan to answer all of those before your write-up is complete, but I just wanted to get those concerns listed up front.
Joe (not a mechanic!) Don't have an account? EMAIL ME
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