The 75 and ZT Owners Club Forums - Cruise+ Loom Retrofit For CDT

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- - Cruise+ Loom Retrofit For CDT (https://www.the75andztclub.co.uk/forum/showthread.php?t=176283)

Hi andre,

I too was in this position with regard to the switches when I did my retrofit.

When I examined plug C0331 on the ECU I noted that pin 23 "E" green/red, pin 28 "F" purple/green and pin 24 "G" green/purple were all present, I therefore concluded that the switches were in place.

The reasoning being that pin 27 wire was missing and so was the cruise control interface.
The steering wheel switches were missing and so were the 2 wires in C20082 pins 4 & 5
So if the wires were there so were the switches

Your picture of the clutch switch shows wires light green/purple, green/red and black which is another clue to the switch being present

In the end I connected everything up and tried it, and it worked.

Pete.

Quote:

Originally Posted by Union Wheels (Post 1668733)

Hi Pete, thanks for the reply. I guess I'll find out about the ECU wiring when I get to adding the missing pin. I'm pretty sure they're there.
Looking at Rimmers' diagrams there shouldn't be any doubt about the clutch switch. But there it is shown as black, mine is white. .
Final conclusions can be made after I've bought and fitted a kit. But that might be in half a year or so.

Today I went and bought everything I need for doing the wiring. Plenty of black cable (PVC, 0,75 sq mm, I'm not really happy with it but couldn't find any better), some 3M branded bits for doing the "piggyback" thingy, self-vulcanizing isolation tape for packing in the 3M bits, some textile isolation tape for making a neat loom, and some 3/1 mm heat shrinking sleeve with glue for the to be soldered connections. I hope it shrinks enough to hold onto the original 0,5 sq mm wires.

By the way, the cruise interface plug in my picture is from a petrol car. I now have one from diesel also, so I'd have the correct colours and wouldn't need to move the connectors in the plug.

I've put the dash together again with all the wiring in place and a hole for the steering wheel buttons made.
The only thing I'm concerned about, both the cruise control master switch and the heated seat switch have slightly more dimmed backlighting than the ATC and stereo panel. I've yet to check the voltage but perhaps this is normal?

When I finally get it to work, I will amend Pete's excellent how-to with some pictures and explanations for future enthusiasts.

http://www.the75andztclub.co.uk/foru...6&d=1400362299

http://www.the75andztclub.co.uk/foru...7&d=1400362304

http://the75andztclub.co.uk/forum/at...1&d=1400362302

http://the75andztclub.co.uk/forum/at...1&d=1400362302

Second test drive done today (in town).

I didn't expect it to work that way without a T4 session.
I found a thread by bigruss42 on mg-rover.org where he describes his retrofitted cruise control funcionality prior to having the car T4'd:

Quote:

Originally Posted by bigruss42

Cruise can be enabled at 29mph.
Press master switch - no warning light on dash.
Press Res.- warning light comes on.
Press Set - Cruise set at current speed.
Repeatedly press Set - incremently increases cruise speed.
Press and hold Set - increases cruise speed until released.
Use accelerator for less than 30 secs - cruise resumes at previous speed.
Brake and clutch switches work as they should - suspends cruise.
Press Res.- suspends cruise.
Press Set - cruise resumes at current speed
Press RES. twice - cancels cruise, light goes out, can then only be reset by the master switch.

My cruise control works in a different way:

Cruise can be enabled at ~38 km/h (my speedometer over reads by ca 12% so it's actually ~34 km/h or ~21 mph).
Press master switch - no warning light on dash.
Press Set - warning light comes on, cruise set at current speed.
Repeatedly press Set - incrementally increases cruise speed.
Press and hold Set - increases cruise speed until released.
Use accelerator for less than 30 secs - cruise resumes at previous speed. (haven't tried actually)
Brake and clutch switches work as they should - suspends cruise.
Press Res. - warning light goes off, suspends cruise.
Press Res. again - warning light comes on, resumes cruise at previous speed.
etc

Can't say I'm not happy :D
Only one thing missing from perfect, there should be a "-" button for decreasing speed. Why did they even put the dummy middle button in there? Just so it would be symmetrical with the ICE buttons?

You don't need a minus button - just tap the RESUME button, then tap the SET when you get to the lower speed. :D

Quote:

Originally Posted by Mike Noc (Post 1691674)

You don't need a minus button - just tap the RESUME button, then tap the SET when you get to the lower speed. :D

Correct ;) But that's 2 clicks instead of 1 and no "fine tuning". Plus there is a dummy button with no use.

Fantastic work sirs! I've parked this idea for years with an idea to make my own loom, but never actually doing it!!! It is SO reassuring that it is possible!

Has anyone got a copy of those two pages of the wiring diagram (I'm not sure I have it) - and I'll try and put together a pictorial how-to to complement this thread (or has it been done already?)

Thanks again!!! :bowdown: