Of course the cruise control doesn't work, and I want to make sure I fix the right thing. I have read dozens of posts mentioning the vacuum lines, the brake switch, the cruise control ECU.... I'm wondering where I should look given this circumstance: I push the master control switch near my knee, it turns on fine. I get to the speed I want, and I pull the set button, I hear a click from the set button, but other than that click, it is as if I hadn't done anything. No additional lights illuminate, and to reaction from anything else. Does this sound like purely an electrical problem? When people fix their CC by replacing/repairing their vacuum lines, did their CC light illuminate on the instrument panel when they pushed the set button?

Car: 1998 4.0 V8 Disco I

I have checked everything down by the brake (switch and lines), and it all seems to be in order.

 

I had to replace my vacuum lines, and I did get the power light when i pressed the powe button on the right panel of dash buttons, and similarly just got nothing when I pressed the set button on the wheel. I suppose you're at least on the right track. The vacuum lines are easy enough to check, mine had a rather large hole in it.
Hope that helps,

Ben

 

well i have the same problem my lines all "llok" good and i dont get a light on the dash just on the button and when i hit set i hear NOTHING

 

My reply isn't any help but i have the same problem. I own a 98 disco and my CC doesn't work either, I don't see a light when i press the master switch either. Maybe this is a very common problem..

 

You have a different problem then most, have you checked your fuses and the power to your cruise control?
Mike

 

You can just look at the lines and call them OK, you really need to remove and or replace them checking all the connection and especially the bends in the hose. Also crawl under and check the line to the cruise control switch located on your brake pedal.
Mike

 

Well, I felt stupid when I went to check the vacuum lines again. I had only checked them at the brake switch and the vacuum pump. This time I followed the lines up to the T-connector and the actuater. Lo and behold, all three connections at the T-connector were cracked and barely attached, and it wasn't even connected to the actuater at all!? After snipping the ends and reattaching everything, it works fine. I'll be buying new lines soon just because the rubber felt dry.

Moral of the story, check ALL the connection points, just like Mike said.

Thanks guys!