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Vxt Aux Pump On/off Conditions


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#1 Ormes

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Posted 11 August 2019 - 08:54 AM

Does anybody know the conditions under which the Aux Water pump activates?... Mine runs when I turn the ignition on (without the engine running) in ambient temps of around 20 degrees (not tested at a lower temperature). Note that I have recently changed the pump, and have also tapped into the relay control cable to activate via a switch that just runs to ground. The switch works perfectly and turns the pump on and off with the ignition off as you would expect. Ultimately the only things that can ground the cable are the switch or the ECU... Strange? Can somebody nip out and see what their pump does with ignition on/engine off? 😉



#2 vocky

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Posted 11 August 2019 - 09:46 AM

according to the wiring diagram the ECU controls the pump with a negative feed to the pump relay



#3 Ormes

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Posted 11 August 2019 - 10:55 AM

Thanks Vocky

 

That's exactly what I understood too, and exactly how I override it with a switch on the dashboard that just runs this spliced feed to ground.  As I say above, the switch sucessfully turns the pump on and off when the ignition is off (which it should), but when you turn the ignition on, the pump fires.  To me, it can only be the ECU doing this... and want to confrim that this is standard behaviour or not.

 

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#4 Ormes

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Posted 11 August 2019 - 04:54 PM

Thanks to hairy who confirmed it that his car exhibits the same behaviour! thumbsup

#5 ayresyy

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Posted 12 August 2019 - 07:14 AM

Does anybody know the conditions under which the Aux Water pump activates?... Mine runs when I turn the ignition on (without the engine running) in ambient temps of around 20 degrees (not tested at a lower temperature). Note that I have recently changed the pump, and have also tapped into the relay control cable to activate via a switch that just runs to ground. The switch works perfectly and turns the pump on and off with the ignition off as you would expect. Ultimately the only things that can ground the cable are the switch or the ECU... Strange? Can somebody nip out and see what their pump does with ignition on/engine off? 😉

 

 

  Curious to know exactly where you made the connection to the relay if it only needs grounding, I wouldn't mind adding a switch off delay timer to keep the pump flowing for 5 mins after switch off.



#6 Ormes

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Posted 12 August 2019 - 08:25 AM

 

Does anybody know the conditions under which the Aux Water pump activates?... Mine runs when I turn the ignition on (without the engine running) in ambient temps of around 20 degrees (not tested at a lower temperature). Note that I have recently changed the pump, and have also tapped into the relay control cable to activate via a switch that just runs to ground. The switch works perfectly and turns the pump on and off with the ignition off as you would expect. Ultimately the only things that can ground the cable are the switch or the ECU... Strange? Can somebody nip out and see what their pump does with ignition on/engine off? 😉

 

 

  Curious to know exactly where you made the connection to the relay if it only needs grounding, I wouldn't mind adding a switch off delay timer to keep the pump flowing for 5 mins after switch off.

 

 

Behind the NSR (LH) arch liner there is a thick loom that is visible on top of the subframe between the roll hoop leg and boot.  Unpick this and then splice (not cut) into the VTOG (violet / orange) wire.  Run the additional wire to the front of the car then connect to the first pole on a switch, then run the other pole to ground (I used the gear selector mechanism).

 

Same principal works with the fan, however the loom is under the centre console and the wire is blue / grey.

 

thumbsup
 



#7 ayresyy

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Posted 13 August 2019 - 06:59 AM

 

 

Does anybody know the conditions under which the Aux Water pump activates?... Mine runs when I turn the ignition on (without the engine running) in ambient temps of around 20 degrees (not tested at a lower temperature). Note that I have recently changed the pump, and have also tapped into the relay control cable to activate via a switch that just runs to ground. The switch works perfectly and turns the pump on and off with the ignition off as you would expect. Ultimately the only things that can ground the cable are the switch or the ECU... Strange? Can somebody nip out and see what their pump does with ignition on/engine off? 😉

 

 

  Curious to know exactly where you made the connection to the relay if it only needs grounding, I wouldn't mind adding a switch off delay timer to keep the pump flowing for 5 mins after switch off.

 

 

 

 

   Thanks for the info, the fan override is another job on my list!

 

 

Behind the NSR (LH) arch liner there is a thick loom that is visible on top of the subframe between the roll hoop leg and boot.  Unpick this and then splice (not cut) into the VTOG (violet / orange) wire.  Run the additional wire to the front of the car then connect to the first pole on a switch, then run the other pole to ground (I used the gear selector mechanism).

 

Same principal works with the fan, however the loom is under the centre console and the wire is blue / grey.

 

thumbsup
 

 

 

   Thanks for the info, the fan override is another job on my list!

 

 


Edited by ayresyy, 13 August 2019 - 07:01 AM.


#8 Ivor

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Posted 13 August 2019 - 07:18 PM




Does anybody know the conditions under which the Aux Water pump activates?... Mine runs when I turn the ignition on (without the engine running) in ambient temps of around 20 degrees (not tested at a lower temperature). Note that I have recently changed the pump, and have also tapped into the relay control cable to activate via a switch that just runs to ground. The switch works perfectly and turns the pump on and off with the ignition off as you would expect. Ultimately the only things that can ground the cable are the switch or the ECU... Strange? Can somebody nip out and see what their pump does with ignition on/engine off? 😉



Curious to know exactly where you made the connection to the relay if it only needs grounding, I wouldn't mind adding a switch off delay timer to keep the pump flowing for 5 mins after switch off.




Thanks for the info, the fan override is another job on my list!

Behind the NSR (LH) arch liner there is a thick loom that is visible on top of the subframe between the roll hoop leg and boot. Unpick this and then splice (not cut) into the VTOG (violet / orange) wire. Run the additional wire to the front of the car then connect to the first pole on a switch, then run the other pole to ground (I used the gear selector mechanism).

Same principal works with the fan, however the loom is under the centre console and the wire is blue / grey.

thumbsup


Thanks for the info, the fan override is another job on my list!
Me too




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