XF Ghia - Cruise Control. Now I want to get it working

[xr6tjet 98]

Hi guys,

 

I'm at the point where I have got everything working beautifully in my XF ghia and the only mystery that remains is the cruise control. The original vaccuum actuator in the car was completely rooted (cable broken etc) so I removed it and replaced it with a later 87 model actuator (all I could find in nice condition). The only notable difference I can see is that it doesn't have an earth lead coming out of the casing.

 

Now - the problem:

 

I have my 85 cruise control ECU behind the trip computer, the red led lights up when I turn the car on, it flickers when i press the "SPD" button on the binaccle controls (that means its working??). I'm driving and I hit the 'SPD' button then I hold the 'SET' button and nothing happens. I have no idea how to diagnose these things, do they have a fuse? Is there a way to test the vaccuum actuator? Anybody with experience in these please help me out!

 

Regards, Alex.

[Mr Polson 10,214]

Red LED? Where's that located?

My Ghia never had a LED to do with cruise (not that I saw).

 

Check that both brake switches are plugged in, apart from that I have no idea.

[xr6tjet 98]

Red LED? Where's that located?

My Ghia never had a LED to do with cruise (not that I saw).

 

Check that both brake switches are plugged in, apart from that I have no idea.

1985 cruise control ecus had a red led on it. Anything onwards had no LED. I even tried a 1987 ecu and still not working. Tested both brake light switches and they work perfect. Has to be something else. How do I find out if the cruise control unit is stuffed?

[Thom 6,654]

try replacing the switch in the end of the master cylinder, don't know if xf use it, but e series do and I know of quotes a few Cara that switch was the only problem with the cruise control (it didn't cause any dash lights either

[xr6tjet 98]

Don't think they have a switch there that might be a newer model cruise setup. In the XF its just an ECU and a control unit. Any assistance guys?

[Outback Jack 6,352]

If the earth lead came out on the old vaccuum actuator, then there was a reason for it to be there. Between models could of been a range of changes.

I would hit the wreckers and buy the whole thing out of same model car to be safe. If that actuator wasn't earthed and it should be,  like on the original, could of blown something in the CC ecu.

[xr6tjet 98]

To me the loom looks like it provides an extra earting point for the CC unit. In my new unit the cable doesn't break off in a 'T' and have that extra earth. I assume the later versions earth through the loom's negative terminal. I have my old actuator that might be functional still I will need to try a new cable. It never worked to begin with though. I can always try.