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Discussion Starter #1 (Edited)
Half an hour to retrofit a cruise control lever and lower cowl, followed by and hour and a half upside-down in the footwell trying to understand why the clutch switch imagines the pedal has been depressed.

To play this game you need to be fit, young and flexible, and capable of inverted use. I am not.

It took me half the time to figure out how to remove the poxy switch. The answer, which seems to be unrecorded anywhere else on the internet, is to twist it 90degrees. It will then lift out.

But why doesn't it work? A multimeter shows it's fine. There is no external sign of wear at all, but the plunger seems to be about 4mm too short. So when the pedal is at its normal height, the plunger isn't pressed in and the switch thinks I have my size 10 on the pedal.

There is no sign of wear anywhere in the pedal mechanism, nothing bent, so it appears the only explanation is that the plastic switch has shrunk. Eh?

I've stuck a small magnet on the plate that depresses the plunger, to take up the slack. So for now it works. But I'd love to know what the hell has gone on here, and whether a new switch would solve the problem? I did think about taking it apart to see if there was internal wear I could pad out, but I need to use the car and I am sure it will be filled with ping****its.
 

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Assuming it's the same as a brake light switch, just remove the switch,pull the plunger out (you'll hear it click) & refit the switch. It will automatically set itself to the correct position.
 

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You need to give the switch a properly good tug. I thought mind was knackered but take it out, disconnect it and pull out when standing the right way up. I used my teeth to yank it.
 

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What has happened is that at one point in the past is that the pin has sheared on the clutch pedal causing the pedal to return way too high and then pushing the switch all the way inside. 90% of the time when the pin is replaced no one thinks to check the switch.

To fix it, grab the plunger with some pliers and pull it back out. You may need to use a lot of pressure but it will come out.

When done, not only will your cruise control now work, you will also see an improvement in MPG, throttle may be a little less juddery at even speed and the revs won't continue to rise when you depress the clutch (this applies to the 2.0 petrol, not sure of the effects on other engines.)
 

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In situ ...it takes a mighty hard pull to get that plunger out with pliers. To the point where you think, no way, its gonna snap! I need two hands on the pliers to do it. I can't imagine its possible to do it when removed, without a vice.


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Discussion Starter #8
Thanks all. I did try pliers, but mindful of the fact it's a puny piece of plastic perhaps I was being too much of a wuss. I'll be a bit braver tomorrow, rain permitting, as today the cruise wasn't working reliably.
 

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If you've got the switch off the car it can be opened fairly easily so you can see what's going on. The pin is grooved (like the barrel of a dart) and a spring clip rests in the grooves, if (without taking it apart) you pull the pin hard enough it'll overcome the clip and come out. When you put it back on the car and release the clutch pedal it'll find its natural position.....as mentioned earlier in the thread.

And yeah, it's a bayonet fixing, can't believe it's not mentioned in one of the many threads about non-functioning cruise control.

All the best

Pub
 

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Discussion Starter #10 (Edited)
I put it in the vice and tugged and it popped right out. How utterly bizarre. I was tempted to take it apart to see how they'd incorporated a adjustment/crumple zone into a switch, which is I suppose the idea - so if the switch jams it can't prevent the pedal having full movement, so thanks for the explanation Pubsinger. Or maybe it's just so they can sell lots and lots of switches :)

It may well be mentioned somewhere in a thread about cruise control, but my Googling on terms like 'Alfa 147 remove clutch switch' failed to find it. I was able to find a good image on eBay that helped. It's a 30sec job to remove and disconnect once understood :)
 

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What has happened is that at one point in the past is that the pin has sheared on the clutch pedal causing the pedal to return way too high and then pushing the switch all the way inside. 90% of the time when the pin is replaced no one thinks to check the switch.
That or the clutch master cylinder has been replaced & the switch not reset, as you say it's easy to forget about it.



... And yeah, it's a bayonet fixing, can't believe it's not mentioned in one of the many threads about non-functioning cruise control.
It's been mentioned in at least 2 threads from the AO archives,
by you http://www.alfaowner.com/Forum/alfa...147-clutch-mystery-andamp-cruise-control.html
& me http://www.alfaowner.com/Forum/alfa-147-156-andamp-gt/149221-cruise-control-not-working.html
 

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Discussion Starter #13
Well it all works fine now, although I don't so far like cruise control much. With so much traffic it's endless use of + &- and the pedal is easier. Maybe at 3am on empty motorway but not the ever-expanding 50mph bit of the M3 today.
 
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