Td5 cruise control with a speedo cable

[Hazza]

Maybe a very niche use case, but a little project I've been thinking about and finally started is to get the cruise control working on my defender while retaining the TDI cable-driven speedo.

Initial thoughts included creating some sort of splitter to drive both the Speedo and a speed sensor. But then I realised that the sensor could probably be modified to sit between transfer box and Speedo cable.

Worth noting, I'm running a discovery ECU, so makes sense to use the discovery sensor which has a different number of pulses per revolution to the defender sensor (I believe). Also helps that I had the discovery sensor to hand.

Photos are pretty self explanatory, but essentially I took the sensor apart, then pulled everything apart (all press fit). Then drilled a 4mm hole through the central shaft and out of the top of the casing.

Next step will be to affix to the end of the speedo cable somehow, and shorten the cable outer to take the sensor's depth into account. I'll update as I progress.

[toenden]

Great! Getting the Cruise to work on my recently fitted td5 was one of the "to-do's" of this winter, so I am looking forward to see your findings. My initial plan was a transducer cut into the speedocable as on my TerraFirma (in the other car) but your way could prove even better/cheaper/easier.

So please keep up the posting/playing with it 🙂

/mads

Edited November 29, 2023 by toenden
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[Hazza]

Glad this might be of use to someone else!

I'll pull the speedo cable off next time I'm working on the car and see how/if it can be grafted onto the sensor, I expect that this will be relatively easy and I'll then just need to modify the clamp to hold the cable to the sensor.

Updates as and when I have them 

 

[Sigi_H]

I allways had the idea to use a small Arduino and a stepper motor on the speedo to adjust different tyre diametrs for the speedo. Between 255/16 MTs in summer and Hakapellitta 235/16 in winter was a difference of 8%.

No more cable and no different gears for the speedo drive in the LT230. Only the TD5 electronic pick up, an Arduino and a stepper motor on the rear of the speedo. Everything else is software.

I never did it unfortunately.

I only trust selfmade electronics 🤣

https://store.arduino.cc/products/arduino-nano-motor-carrier

 

Edited December 1, 2023 by Sigi_H

[Hazza]

Sounds very clever - waaay above my abilities!

[Sigi_H]

don`t underestimate yourself.

Arduini is quite easy and everybody can program it. Most of the work is mechanical (how to connect the stepper to the speedo).

I am even planning to make new electrics for the 110

There has been 2 options.

1. as original as possible

2. Completely modern with a bus system

I decided for the second and an Arduino as center.

There will be a RS485 Bus to the front and to the rear. Front receiver and rear receiver will be identical with relays and their own fuses on it for each electric load. This means in deed 4 relays for 4 indicators and separate relays for each light.

But the great advantage is: No cabling for fuses and only a small harnes for front and rear.

There will only be a power line and a bus line to the front and to the rear.

Until now it is only in my head, but I know it will be necessary soon.

 

[Hazza]

Sounds like a great project, please share details as you go!

[Sigi_H]

1 hour ago, Hazza said:

Sounds like a great project, please share details as you go!

I will and I welcome help, since this is not a small development. But universal and usable for any old car.

All old dashbord switches and steering column switches will be used. It doesn`t matter, how inputs on the Arduino are triggered. Any kind of switch can be used for any funktion.

When the project is started I`ll make a new thread. I`d like to use a lot of component from China. The prize will be a little less than a complete harness and the effort to put it all in the car will be a lot less than a complete harness.

So far my ideas and hopes 🤭

 

[Troll Hunter]

Sigi_H, I envy your arduino prowess!  I’m just about completing a full rewire of my 1991 110CSW, without an arduino, but following many of your philosophies.  I’v got twin batteries, one dedicated solely to the starter, and all other loads supported by the other one.  In an attempt to minimise switch burn out every circuit that draws more than 4 amps I’ve routed through a fused relay, which means quite a lot of relays when I’ve added driving, front fog lights and work lights all around, plus various 20 amp utility outlets.  I’ve also included a dedicated earth from each consumer going back to an earth busbar.  I have five of these in total, all going back to the battery negatives.  I’m trying to avoid poor earth connections that rely on earthing through body work of chassis connections which always seem to be plagued with rust induced poor connectivity.

I’ve also added front and rear Anderson sockets, fed through lengths of welding cable, to enable connecting jump leads to another vehicle.  These also come from and return to the accessory battery, not the starter battery.

Your proposed use of an arduino and associated bus sounds very good and should simplify the cabling tremendously.  I wish I had the knowledge and skill sets necessary.  I’d still recommend fuses in the power supply to each user since these will still be carrying currents able to generate major problems (short circuit fires!).

Mike