Cruise Control not working on a Discovery 300 TDi

[Markyh]

I have a 1997 Tdi disco with cruise control fitted. However since I bought it this has never worked. When you switch it on using the button on the dashboard the light comes on. However when you try to set it using the buttons on the steering wheel nothing happens.

Electrics really aren't my strong point. I wondered if it might be the fuse but a couple of other items run off the same fuse and they work fine.

The guy who had it before me fitted a CD Changer under the passenger seat and sub woofer under the glove box is it possible he may have used the wiring for the cruise control to power this? (Like I say electrics are not my strong point!)

Does anyone have any ideas? Any help gratefully recived.

[thebiglad]

I have a 1997 Tdi disco with cruise control fitted. However since I bought it this has never worked. When you switch it on using the button on the dashboard the light comes on. However when you try to set it using the buttons on the steering wheel nothing happens.

Electrics really aren't my strong point. I wondered if it might be the fuse but a couple of other items run off the same fuse and they work fine.

The guy who had it before me fitted a CD Changer under the passenger seat and sub woofer under the glove box is it possible he may have used the wiring for the cruise control to power this? (Like I say electrics are not my strong point!)

Does anyone have any ideas? Any help gratefully recived.


90% of all cruise control problems relate to the vacuum hoses and nothing at all electrical !!!

The hoses deteriorate at their ends and start to leak - cure is cut off the perished bit (usually 1-2cms) then reconnect and Bob is very often, your mum's best friend !!

[DiscoTdi]

as theBigLad says 90% of the time its the rubber hoses, on mine they had gone at all THREE ends, including at the pump end which is hidden under the jack storage at the front.

Access to the pump is a nightmare, but I found it's easier to release from underneath by pushing in the three rubber mounting feet. You will find that the same guy who designed the postion of the upper mounting bolt for the starter motor and the engine serial No also designed the exact length of electric cable used to connect to the pump :(

You will probably find that you can just about pull it into view to remove the connector in order to remove the pump and inspect the hose connection for splits.

There are a number of electrical checks I can advise on whilst teh car is staionary, to power up the pump, enable vacume to the actuatore, check the function of the steering wheel switches etc are all working etc, but does require access to the connector on the ECU behind the glove box and applying voltages / earths to wires. So depends how confident you would be doing that.

On mine having gone through all the checks, it was a faulty cruise control ECU, which I had to replace with a second hand one as not easy to repair.

I'd check out the mechanical side first and see how you get on.

Cheers

[Stu2985]

always had probs with mine

all my pipes were shot even after cutting back and refitting they never worked

how do you do the check where you connect a battery across the 2 terminals again ?