Cruise control D1

[roverv8]

Ok,
Have read most of the cruise control threads on here, & check out RAVE trouble shoot for the cruise
I replaced the vacum lines, adjusted the both switches on the brake pedal, tested the vac pump, horn & SRS are both functional.
The cruise finally worked!!
BUT it only works when it feels like it,
So i changed the lockout relay, tested another on/off switch, rechecked adjustment on the brake pedal, even spliced the earth wire to the ECU.

Question, when the ECU craps out do they fail all together or will they work on & off??
Anyone know what the diode does and could it work on/off.
Funny thing is this behaviour is happening on 2 different vehicles,
only works when it wants to, exactly the same thing???
Very frustrating :wallbash:

[PAT303]

Are you holding constant speed while engaging it?,I found the best way was to hold the switch until I felt the peddle fall away from my foot,worked every time. Pat

[roverv8]

Yes, done that.
Like said, only works when it feels like it,
Ive had them going on both vehicles for a month or so but sometimes they just don't work at all.

Cheers Luke

[bee utey]

Don't think I've met a D1 cruise control that stayed working for long. I've test driven dozens of D1's on the local freeway and you might get 1 in 10 to work, even after fixing all the vacuum hoses. Over to the experts.

It might save a lot of grief to fit an aftermarket one. The AP60 one has been very reliable for my customers.

[PAT303]

Mine worked perfectly after the hoses were changed,have you tested the bellows?. Pat

[PAT303]

Just thought of the rotary switch behind the steering wheel,have you got someone,(Ultra Tune) in your area?,get them to hook it up and test the cruise circuit. Pat

[roverv8]

Just thought of the rotary switch behind the steering wheel,have you got someone,(Ultra Tune) in your area?,get them to hook it up and test the cruise circuit. Pat


Horn, SRS, work fine off the coupling, have tested the +/- Switch on the wheel
it's coming through to the cruise ECU plug, test method
Refered from RAVE,

[Scouse]

Question, when the ECU craps out do they fail all together or will they work on & off??
My P38 has the same ECU as the D1 & I had exactly the same problem. The cruise would work great for about 10% of the time but nothing for the other 90%.
I did all the tests & they all pointed to the ECU so I bit the bullet & replaced it a few weeks ago. The cruise has worked great ever since :).

[roverv8]

Thanks Scouse,
In a way it's good to here, Ive been through everything else,
Im going to bite the bullet & replace the ECU.