AC switch mod to B5-ACS

OTT · Post by **OTT** » Tue Jan 08, 2008 10:26 am

I understand the note saying to 'ground the other side of the AC switch' in order to use it for boost control but I have some questions...

1. Can I simply wire into the blue/red wire which is fed from the AC thermostats chopped connection? there is a diode inline on the climate control's circuit board but it does go to earth via green wire from the fan-switch?

2. If the above option cannot be used then I do solder to the other side of the switch then do I need to 'invert the input' on Smanager since it grounds when the button is OUT i.e. in the off position?

Post by **Spunkster** » Tue Jan 08, 2008 12:37 pm

Switches vary form car to car as does wiring. You will have to work out with a multimeter which ries form the switch go where and wire it accordingly.

OTT · Post by **OTT** » Wed Jan 09, 2008 5:59 am

thats what I did buddy. But basically want to know if a diode will stop it functioning? I get continuity.

cheers

Post by **Spunkster** » Wed Jan 09, 2008 10:44 am

You should not have to use any diode. You are just using the ac switch as an interupt to ground.

OTT · Post by **OTT** » Thu Jan 10, 2008 12:29 am

Spunkster wrote:You should not have to use any diode. You are just using the ac switch as an interupt to ground.

The factory put thaty diode in to protect the thermostat from current coming from the dimmer circuit.

Do I use datalogging to check which switches are working? or is there a way to see the status of switches live?

Post by **Spunkster** » Thu Jan 10, 2008 11:03 am

THe sensor list shows what inputs and outputs are active.

If you still have AC you cannot use the AC input.

OTT · Post by **OTT** » Wed Mar 05, 2008 9:47 am

I connected the output from the ecu to the BLUE/RED wire that goes into the back of the heating controls. This wire used to come from the thermostat/temp sensor that used to go into the condensor in the dash. This wire is no-longer connected to that sensor but as said its wired to the ECU.

My question now is will the diode stop the ECU seeing the earth??

I have continuity with earth when the AC switch is on.

But do you think/know is the diode shown in the circuit diagram will affect it seeing the ground/earth?

Just so you can see which part of the diagram im talking about...
from the 4x speed fan-switch which is where the earth goes, to the right of that there is a DPST double pole single throw switch (the AC switch) and just above that the wire in the chart has a diode in it, this wire now goes to the ecu pin assigned for selecting hi/lo boost.