Wiring Through Steering Column

WiltshireTouring · 28th April 2024, 11:12

So I am halfway through a plan to install a heated steering wheel.

I've got the wiring from the battery sorted and I've already got the wheel retrimmed with heated elements in and tested it's all working.

My issue is now that I need to wire through the clock spring or find a way to bypass whilst still allowing for the rotation of the steering wheel.

I've thought of a few different ways but none of it makes sense without adapting the clock spring.

I have seen there are two spare pins in the connector to the clock spring and wondered if they were connected to anything the other side?

The other thing I've seen mentioned is that splicing in to the horns/controls and activating anything will set the horn off until the ignition is switched off again?

Any help would be much appreciated please see attached images for context!

Lee T · 28th April 2024, 12:51

The spare pins are for cruise control. I'm not an expert but unless the power required for your heated wheel is above what the clocksprings can handle it should be ok to use the cruise pins. There are a few members who will be able to confirm this either way. Nice modification though, hope it's as easy as it appears

Lee.

WiltshireTouring · 28th April 2024, 14:26

Thanks Lee! I've had a look on the dodgy eBay listing for the heated elements and it only states it's a 12v powering the two 18w heated pads.

If the cruise wiring is the other side I could splice into that as the car never came with it as a function and it's not a daily so wouldn't need the function anyway.

Jamiewelch · 28th April 2024, 14:50

Quote:

Originally Posted by WiltshireTouring

Thanks Lee! I've had a look on the dodgy eBay listing for the heated elements and it only states it's a 12v powering the two 18w heated pads.

If the cruise wiring is the other side I could splice into that as the car never came with it as a function and it's not a daily so wouldn't need the function anyway.

The wiring for the cruise switches is 0.5mm. I'd definitely be on the side of caution on that one. If the wire is only 0.5mm then the rotary coupler probably won't handle the current.

Lee T · 28th April 2024, 15:59

Quote:

Originally Posted by WiltshireTouring

Thanks Lee! I've had a look on the dodgy eBay listing for the heated elements and it only states it's a 12v powering the two 18w heated pads.

If the cruise wiring is the other side I could splice into that as the car never came with it as a function and it's not a daily so wouldn't need the function anyway.

If you have no cruise the plugs may be empty both sides as mine are. Adding to them would be easy, but if as stated, above the coupler can't handle it, then you will need a new plan. I have an old coupler here you can have for research and testing if it helps.

Lee.

SD1too · 28th April 2024, 16:45

Hello Laurence,

Your two 18 watt heating elements will draw about 3 amps.
The rotary coupler (clock spring) currently handles the radio and cruise control controls plus the horn buttons in a relay coil circuit.
All these are very low current consumers, nothing approaching 3 amps. I therefore doubt that the rotary coupler has been manufactured to carry such a load.
You should therefore accept Lee's kind offer of testing the circuit using his spare coupler.

Simon

WiltshireTouring · 28th April 2024, 18:44

Thanks guys, a couple of the techs at work were a bit dubious of the power the coupler could take. I do have a spare one so thank you for the offer Lee!

The other option would be to get some higher gauge wire going through the coupler to the unused cruise control pins or to try and have a hole straight through the bottom of the wheel and some sheathed slack wiring to allow for the rotation.

Those are my last options I think

Mike Noc · 2nd May 2024, 08:43

Quote:

Originally Posted by WiltshireTouring

So I am halfway through a plan to install a heated steering wheel.

I've got the wiring from the battery sorted and I've already got the wheel retrimmed with heated elements in and tested it's all working.

Just out of interest what size fuse are you using for the element?

WiltshireTouring · 5th May 2024, 10:32

Think it came as standard with a 15A fuse, I also have a 60A fuse on the mainline from the battery as a precaution.

I have been revisiting this today and am currently on the thinking of having a curly 12v cable within the steering wheel to allow for rotation.

Mike Noc · 8th May 2024, 07:01

Just checked to see if I had the old broken coupler to test it for you but sadly it's been thrown out. I would have shorted the two cruise wires together and fed them with a 12 volt supply from a battery via a 15 amp fuse. As long as the fuse blew you would be good to go, but I'd expect the cables to overheat, which would not be a fail safe circuit in the car.

28th April 2024, 12:51	#2
Lee T Gets stuck in MG ZT Join Date: Jul 2014 Location: Liverpool Posts: 875 Thanks: 180 Thanked 248 Times in 189 Posts	The spare pins are for cruise control. I'm not an expert but unless the power required for your heated wheel is above what the clocksprings can handle it should be ok to use the cruise pins. There are a few members who will be able to confirm this either way. Nice modification though, hope it's as easy as it appears Lee. __________________ [SIGPIC][/SIGPIC]

28th April 2024, 14:26	#3
WiltshireTouring Newbie MG ZT-T Join Date: Mar 2023 Location: Wiltshire Posts: 27 Thanks: 0 Thanked 0 Times in 0 Posts	Thanks Lee! I've had a look on the dodgy eBay listing for the heated elements and it only states it's a 12v powering the two 18w heated pads. If the cruise wiring is the other side I could splice into that as the car never came with it as a function and it's not a daily so wouldn't need the function anyway. __________________ WiltshireTouring on TikTok

28th April 2024, 16:45	#6
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,581 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Hello Laurence, Your two 18 watt heating elements will draw about 3 amps. The rotary coupler (clock spring) currently handles the radio and cruise control controls plus the horn buttons in a relay coil circuit. All these are very low current consumers, nothing approaching 3 amps. I therefore doubt that the rotary coupler has been manufactured to carry such a load. You should therefore accept Lee's kind offer of testing the circuit using his spare coupler. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

28th April 2024, 18:44	#7
WiltshireTouring Newbie MG ZT-T Join Date: Mar 2023 Location: Wiltshire Posts: 27 Thanks: 0 Thanked 0 Times in 0 Posts	Thanks guys, a couple of the techs at work were a bit dubious of the power the coupler could take. I do have a spare one so thank you for the offer Lee! The other option would be to get some higher gauge wire going through the coupler to the unused cruise control pins or to try and have a hole straight through the bottom of the wheel and some sheathed slack wiring to allow for the rotation. Those are my last options I think __________________ WiltshireTouring on TikTok

5th May 2024, 10:32	#9
WiltshireTouring Newbie MG ZT-T Join Date: Mar 2023 Location: Wiltshire Posts: 27 Thanks: 0 Thanked 0 Times in 0 Posts	Think it came as standard with a 15A fuse, I also have a 60A fuse on the mainline from the battery as a precaution. I have been revisiting this today and am currently on the thinking of having a curly 12v cable within the steering wheel to allow for rotation. __________________ WiltshireTouring on TikTok

8th May 2024, 07:01	#10
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: 11,579 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Just checked to see if I had the old broken coupler to test it for you but sadly it's been thrown out. I would have shorted the two cruise wires together and fed them with a 12 volt supply from a battery via a 15 amp fuse. As long as the fuse blew you would be good to go, but I'd expect the cables to overheat, which would not be a fail safe circuit in the car.