A/C Condenser Fan question

[javadave]

Ok, so I can't find in the FSM under what conditions the condenser fan motor is activated. I have yet to see it run.

I've tested the fan and it does operate fine.

From all the diagnostics I've done the only thing I can find is the negative side to the relay coil is not grounded. When I turn the car on the positive side goes hot, but no ground to engage the relay.

The switched portion of the relay is getting its power, as I was able to jump the connectors and get the fan to run.

I tried looking at the FSM to see where the ground to the relay runs, but the image of the connector is not clear as to which connector its going into ( Section HA, page 62 ).

Is it normal for the fan NOT to come on when the A/C is put on auto and then the Defroster turned on doesn't activate it either.

[nissanfreak12]

As far as I know, the fan should come on when the AC is on. Is the AC blowing cold? Does the AC compressor actually turn on? The electric I think is either there (mainly) for ac condenser to cool the refrigerant down. The other is when the engine temps gets too high, it comes on to attempt to cool down the engine.

Try replacing the relay and see if that helps.

[javadave]

1) No, the ac is not as cold as it used to be
2) Yes, the ac compressor comes on
3) The relay is not the issue.
The relay needs a positive signal and a ground to engage. When I start the car the Positive signal to the relay's coil is sent ( verified with a volt meter ), but no ground. I swapped the fan relay with the ac compressor relay and same thing, compressor comes on, condenser fan does not.
Just trying to figure out where the relay's coil gets the ground signal from.
Thanks

[nissanfreak12]

It very well could be on a time relay type of thing. It very well may be because your refrigerant is low it may cycle the compressor on and off so much or fast, basically not stay on long enough for the fan to kick on. Or the refrigerant may not get hot enough for the fan to kick on. When the AC is on does the larger tube get cold and the smaller one get hot?

[abazz009]

here look at this

http://twinturbo.net/nissan/300zx/tech/ ... uxfan.html

tells you everything you need to know. the aux fan comes on when the coolant hits a certain temperature

[javadave]

Thank you sounderror, that is exactly what I needed !

Much appreciated