Cruise master switch automation

goltho · 28th September 2018, 23:40

I find having to switch on the cruise on the lower dash after starting the car a complete pain in the armpit, so I've decided to so something about it. There's never a time when I actively want the cruise not to be available when driving, and I therefore effectively want to have immediate control on the steering wheel switches.

I've identified the main 12V white/blue feed to the (S124) switch from passenger f/box F26 from Rave page 24 and confirmed it with the meter. I've also identified the blue/orange switched 12V feed from the switch to the main cruise control relay R142 (although not yet confirmed it) and the black earth wire from the switch, presumably for the green light on the switch. There are also two further wires to/from the switch which Rave shows on page 25 as coming from R142 and going to S124 which I'm as yet unclear about.

My plan is to fit a simple on and off delay switch to bypass S124 on the dash; the white/blue feed will run to the On side of the delay switch and be set to around 10 seconds, and the blue/orange feed will run from the Off side of the delay switch and be set to around 1 second. I am assuming in all this that switch S124 is a momentary switch and does not want to be continuously feeding relay R142. Now that may be incorrect but that's been my understanding from an auto-electrician. If it is incorrect, then the need for a short burst from the delay switch would be obviated and I can use an On-only delay switch.

So the question is:- is the cruise control solely powered by the white/blue feed from the existing master switch S124, or are the other two wires involved?

Thanks,

Dougie.

Mike Noc · 29th September 2018, 07:00

I can't remember who it was that did it, but it has been done, and if you solder a link across the two white/blue wires (C0749-1 to C0749-5) at the cruise control switch (S124), then the cruise will be permanently available from the steering wheel controls.

I'm not condoning this, as there was a lot of negative comment about safety at the time, so if anyone has any issues don't shoot the messenger.

.

goltho · 29th September 2018, 09:09

Quote:

Originally Posted by Mike Noc

I can't remember who it was that did it, but it has been done, and if you solder a link across the two white/blue wires (C0749-1 to C0749-5) at the cruise control switch (S124), then the cruise will be permanently available from the steering wheel controls.

I'm not condoning this, as there was a lot of negative comment about safety at the time, so if anyone has any issues don't shoot the messenger.

Great, thanks for that. Nope, not inviting safety comments thanks. It's been well considered.

Dougie.

Mike Noc · 29th September 2018, 11:57

Don't worry Dougie I wasn't going to give you any.

goltho · 29th September 2018, 16:57

Quote:

Originally Posted by Mike Noc

Don't worry Dougie I wasn't going to give you any.

Oh I realise that.

Got 'er sorted, thank you. Entirely straightforward bypass, not as I expected. Just how I want it now.

Dougie.

28th September 2018, 23:40	#1
goltho Can't help myself Rover 75 CDTi 2005 Join Date: Jan 2018 Location: Lincoln Posts: 871 Thanks: 469 Thanked 150 Times in 113 Posts	Cruise master switch automation I find having to switch on the cruise on the lower dash after starting the car a complete pain in the armpit, so I've decided to so something about it. There's never a time when I actively want the cruise not to be available when driving, and I therefore effectively want to have immediate control on the steering wheel switches. I've identified the main 12V white/blue feed to the (S124) switch from passenger f/box F26 from Rave page 24 and confirmed it with the meter. I've also identified the blue/orange switched 12V feed from the switch to the main cruise control relay R142 (although not yet confirmed it) and the black earth wire from the switch, presumably for the green light on the switch. There are also two further wires to/from the switch which Rave shows on page 25 as coming from R142 and going to S124 which I'm as yet unclear about. My plan is to fit a simple on and off delay switch to bypass S124 on the dash; the white/blue feed will run to the On side of the delay switch and be set to around 10 seconds, and the blue/orange feed will run from the Off side of the delay switch and be set to around 1 second. I am assuming in all this that switch S124 is a momentary switch and does not want to be continuously feeding relay R142. Now that may be incorrect but that's been my understanding from an auto-electrician. If it is incorrect, then the need for a short burst from the delay switch would be obviated and I can use an On-only delay switch. So the question is:- is the cruise control solely powered by the white/blue feed from the existing master switch S124, or are the other two wires involved? Thanks, Dougie. __________________ R75 C2 RJBLH Connoisseur CDTi Auto Saloon • Built 08/02/2005 @14:57 hrs: Registered 26/08/2005 • 122nd of 141 built that day • British Racing Green Pearlescent (HFF) • Sandstone leather with black piping (SPJ) • 137,000 miles Last edited by goltho; 28th September 2018 at 23:44..

29th September 2018, 07:00	#2
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,550 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	I can't remember who it was that did it, but it has been done, and if you solder a link across the two white/blue wires (C0749-1 to C0749-5) at the cruise control switch (S124), then the cruise will be permanently available from the steering wheel controls. I'm not condoning this, as there was a lot of negative comment about safety at the time, so if anyone has any issues don't shoot the messenger. . Last edited by Mike Noc; 29th September 2018 at 07:03..

29th September 2018, 11:57	#4
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,550 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Don't worry Dougie I wasn't going to give you any.