Thread: Cruise Control

Hi Guys, I'm new to the forum having joined mainly due to the wealth of information regarding the fitment of a tachometer to Td5 Defenders.

I thought there might be some forum members out there interested in my cruise control project I fitted to my 2002 Td5 110 station wagon. I'm sure cruise control will be of more use to you folks given your long straight roads but I use it a lot when driving my company VW Passat and aside from leather interior and a stereo I can hear it is one of the things I miss most when driving my 110. So, having read all the posts, studied the Defender and Discovery 2 wiring diagrams and done some homework regarding switches I have now completed my project. I believe this will only work on post 2002 Td5 Defenders with standard gearing - overdrives and Discovery transfer boxes render this conversion inoperative, so I am told.

It took all day, bearing in mind that I had to make the looms, drill 4 x 22mm holes in the bulkhead and seat box, crimp on lots of connectors and make switches fit in places where they were never designed to go it was a good day's work.

So the job started with the SET/RES switch which I had thought about for ages, deciding on genuine is best. I wanted it on the steering wheel but no chance of that so the next best place was on the steering column shroud.



This switch is LR part number YUH100320 and needs a 12V input and gives a 12V pulse to the ECU when you wish to SET or RES(ume) your stored speed. The 12V signal for SET goes to ECU pin 11 and the signal to Resume goes to pin 17

Next was the cruise master switch, I needed a latching switch to fit into the switch blank on the central fascia, so chose part number YUG102430 which is a heated seat switch. This sends a 12V feed to pin 15 of the ECU to enable the cruise control, it is also wired up with the side light illumination. A master switch is not essential but my better half hates cruise control so I fitted it so she can switch it off completely and it looks pretty sexy too!

Here is master switch mark 1, amazing what you can do by downloading a motorway symbol, resizing it, printing it on self adhesive label paper to make a template and then carefully scratching away the plastic on the switch blank.




The loom exits through the bulkhead and goes two ways, down to the ECU and across to the brake light switch. There is debate about how you get the cruise to disengage when the brakes are used. I used a Discovery 2 wiring diagram but a Disco has a brake light switch with a normally closed output to the ECU for the cruise and normally open side for the brake lights, not so in a Defender as it only has a normally open brake light switch but this can be sorted with a relay as long as the solution you choose provides 12V to Pin 10 on the ECU you'll be fine. The grommet needs sorting out as the paint was still wet when I took the pic!



Once into the seat box you connect the four feeds to the black ECU plug and connect up the relay to convert the 12V feed from the brake light switch to give 12V to pin 10 when the brake pedal is up and 0V when the brake pedal is pressed. I also wired in a feed for the tachometer to pin 19 while I was down there so I could fit this at a later date.



Total cost about £65 taking into account -

2 x genuine LR switches approx £40

7 x 4 metre lengths of colour coded 1 sq. mm thin-wall cable

Conduit, T piece and gold plated ECU connectors.

1 x switch connector for cruise master switch (heated seat switch)

Various bits of hardware to mount SET/RES switch, captive nuts, screws and insulation tape.

1 bank holiday in the sun!



Cheers, DVT

No wonder the world is getting more complicated- too many clever people out there. Well done.