Switched live power / centre console?

[JonnieD]

I've just got my Top Gear switchable exhaust installed and working via the remote unit on my 997.2 (it sounds great!). And whilst I wait for the replacement switch with the PSE button to arrive, I have a question that someone might be able to answer:

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  Is there a suitable switched live cable I can splice into within the centre console on the 997.2?

I'm being lazy as I know its not that hard to wire back to the fuse box, but it would save me some time.

I did think the live going to Pin 3 of the centre switch might work, as it seemed to be a straight 12V feed but it seems not. I've already got the cable running from the centre console to the back solenoid. That was enough carpet lifting and graft for now!

I have the relay/pcb plus other bits already too.

 

[m1kegibson]

I used pin 3 from the centre switch module (ie the one where Sports mode, PSM button is) in order to switch a relay and change the footwell accessory socket to switched. (my DIY is here: https://rennlist.com/forums/997-forum/1138900-997-2-ignition-switched-footwell-accessory-socket.html)

If we are talking about the same Pin 3, I believe that is switched; certainly it works on my car.

 

[m1kegibson]

I used pin 3 from the centre switch module (ie the one where Sports mode, PSM button is) in order to switch a relay and change the footwell accessory socket to switched. (my DIY is here: https://rennlist.com/forums/997-forum/1138900-997-2-ignition-switched-footwell-accessory-socket.html)

If we are talking about the same Pin 3, I believe that is switched; certainly it works on my car.

I should add that this power source (ie Pin 3) should not be used to power any significant loads. The wiring to Pin 3 is not up to anything substantial so fine for switching a relay but not much more in my view. I am not sure I would use this to power the solenoids directly without first checking the load they present.

 

[JonnieD]

I used pin 3 from the centre switch module (ie the one where Sports mode, PSM button is) in order to switch a relay and change the footwell accessory socket to switched. (my DIY is here: https://rennlist.com/forums/997-forum/1138900-997-2-ignition-switched-footwell-accessory-socket.html)

If we are talking about the same Pin 3, I believe that is switched; certainly it works on my car.

Thanks for this. I think you're right, that the switched power from Pin 3 is ok to use. I think I had a connection issue upstream of the wire that I'd run, as when I went to test it and started the car, it threw up a PSM failure on the dash. But I think its probably only because I'd disconnected the battery whilst I spliced that wire in.

I think the power for a solenoid is pretty low, but I will test it. All I'd done was to connect the source to my meter to check continuity to engine bay.

 

[m1kegibson]

Whenever battery is disconnected, you always get a PSM error. Need to start up, drive round the block and it will clear itself. When you start up next time it should be gone.

 

[JonnieD]

Whenever battery is disconnected, you always get a PSM error. Need to start up, drive round the block and it will clear itself. When you start up next time it should be gone.

Yes indeed.

What was a bit odd was that I drove the car first and no error was shown. But when I'd then stopped, connected the meter to test the voltage from the Pin 3 wire to ground in the engine compartment, it threw up that code plus a spoiler actuation error too!

BTW, that change over valve is rated at 1A maximum current. And that wire from Pin 3 seems to run back to a 7.5 amp fuse, so there really shouldn't be a power rating issue.

 

[m1kegibson]

The wire at rear of pin 3 should be fine for a 1A load.

I am puzzled as to why measuring the voltage should trigger 'failure".

The wiring diagrams I have are a bit confusing but I suspect the fused supply to pin 3 also links to some other control modules so it is possible that something caused a momentary voltage drop and triggered this though how connecting a multimeter (in DC voltage testing mode) would cause a voltage drop is beyond me.

 

[JonnieD]

The wire at rear of pin 3 should be fine for a 1A load.

I am puzzled as to why measuring the voltage should trigger 'failure".

The wiring diagrams I have are a bit confusing but I suspect the fused supply to pin 3 also links to some other control modules so it is possible that something caused a momentary voltage drop and triggered this though how connecting a multimeter (in DC voltage testing mode) would cause a voltage drop is beyond me.

Yes, very odd.

It's sorted now, but whatever it was, also caused the 10A fuse for the PSM control unit to blow!

I think given this has happened, I'm going to run a new feed from the fuse box, and avoid using that wire.

 

[m1kegibson]

Maybe the multimeter was in current(A), Resistance or Diode testing mode when you initially tried. Sounds like a short occurred.

 

[JonnieD]

Maybe the multimeter was in current(A), Resistance or Diode testing mode when you initially tried. Sounds like a short occurred.

It does sound like a short, but it wasn't from the meter. The one I use for car things has a separate connector for current and that wasn't being used. Very strange.

I think when the switch arrives, I'll do what you've done and use the Pin 3 switched live for the relay, but take the load for the solenoid from the cigar lighter (that's easy to tap off from the centre console).