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Discussion Starter · #1 ·
Hello I have a taurus e fan and three different ways to wire it up, not the problem is where does the diode go? I have this one diagram and it really does not explain how the diode should be installed to avoid the high and low speeds to come on at the same time and thus burning up the motor. Thanks , Mark
 

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On your diagram Mark it is only one speed. One relay controls the on off by the engine temp. The other relay controls it when the A/C is turned on. So if the A/C is on before the engine is warm the fans run so the A/C works.

As far as the diodes What they got is for the led light nothing is going to burn that motor up. Mine been how many years running without one. It is a electric motor it dont care about a diode as wired.
 

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The diode is the triangle with the line at the end like this -|<|- It prevents inductive feedback in the circuit that can arc out the contacts. The easiest thing to do would be to put it at the connection of the relay on the fan side and then ground the other. Be sure the line on the diode is pointed the right way.

Also if you can find one in the yard a Volvo fan relay rocks. Look them up, the Volvos also use a very similar fan with in my opinion a better shroud setup.
 

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Discussion Starter · #5 ·
I know this is for a 1 speed fan but it was the closest one to what I am using. and the diode is in the same location. So the diode goes from the power out to fan then to ground? with the arrow pointing towards pos?
 

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Discussion Starter · #6 ·
OK so I need to know what wires I use for the AC there are only two wires going to the actual compressor one green and one black. The back is ground according to my diagrams but my wiring diagram for the 2 speed fan only shows one wire going to the 86 on the 3rd of three relays. It does not show any other wire for the AC so if I attach the green to the relay what do I attach back to the compressor?
Rectangle Handwriting Font Material property Parallel
 

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Discussion Starter · #7 ·
The high lighter lines are the completed wiring -the non highlighted have not been done yet.
 

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I believe this is what you want. When energized, the tap on the positive A/C clutch wire would energize relay C, allowing Relay B pin 85 to be grounded, simulating a low speed fan request from the temperature switch. Also there are some grounds missing from your drawing on the fan and thermal switch, and your toggle switch would be off/auto, with no on(override) position.
 

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Discussion Starter · #9 ·
I believe this is what you want. When energized, the tap on the positive A/C clutch wire would energize relay C, allowing Relay B pin 85 to be grounded, simulating a low speed fan request from the temperature switch. Also there are some grounds missing from your drawing on the fan and thermal switch, and your toggle switch would be off/auto, with no on(override) position.
 

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Discussion Starter · #10 ·
The ground for the e-fan is installed and the thermal switch being the temp sensor? not sure if that is what you mean but if it is then the switch is grounded by way of the engine and in my case there are two temp probes. But if you mean something else then please explain.
 

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The ground for the e-fan is installed and the thermal switch being the temp sensor? not sure if that is what you mean but if it is then the switch is grounded by way of the engine and in my case there are two temp probes. But if you mean something else then please explain.
The assembly labeled thermal switch on your drawing. Just wanted to make sure they are switched to ground and not to 12V or something weird.
 

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Discussion Starter · #12 ·
I wired them according to the directions, I will verify tomorrow, there are no fuses in the harness at this time just to be safe. Once it is all wired and covered I will test the system. for now I am just making sure its ready for the ac to kick it on too. The switch is on/off only and will light up when its on.
 

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Discussion Starter · #15 ·
I meant that I removed the actual fuse from the fuse holder, lol and the guy who wrote it all up did say it was in case of water crossing. I just did it as it was written because I don't have a reason to change it.
 

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Discussion Starter · #17 ·
chrichardson said:
I believe this is what you want. When energized, the tap on the positive A/C clutch wire would energize relay C, allowing Relay B pin 85 to be grounded, simulating a low speed fan request from the temperature switch. Also there are some grounds missing from your drawing on the fan and thermal switch, and your toggle switch would be off/auto, with no on(override) position.
OK so the wire from the ac compressor (green wire) connects from the harness to the compressor, do I splice into that to go to the relay C? Or do I get the wire from elsewhere in the harness? such as the switch inside the vehicle?
 

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The switch on the dash is just an A/C request signal that goes to the ECM. The ECM will then apply power to the A/C clutch as necessary, depending on A/C system pressure and throttle input. I would tap into the green wire for the compressor, wherever is easiest to access.
 

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I don't remember what year your van is Mark, but in the earlier vans, probably up through 95, the ECM/PCM has nothing to do with controlling the A/C.

Where you want to tap into depends on if you want the fan to run all the time when A/C is requested, or only when the compressor is engaged.
 
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