V8V Handbrake microswitch operation. Help requested

[LTP]

Hi all. A question for those who have done brakes work on their Vantages, especially handbrake rebuild.

Ever since I took possession at just over 3 years old my 2015 V8V has had an intermittent issue where, despite me making sure the handbrake is actually fully off, the light on the dash occasionally stays illuminated and I get the bongs and the warnings if I drive off. Lifting the handbrake lever slightly and banging it back down, or waggling it slightly will often extinguish the light and warnings and is my standard on-the-move fix. But I shouldn't need to do this.

I think that whatever activates the microswitch to tell the car that the handbrake is off or the switch position itself is on the limit and needs a little tweak or adjustment so that the switch activation is more reliable when the handbrake is released. The fact that I can make the light go out by banging or waggling the lever makes me think that the switch is somewhere on the handbrake lever assembly or cables in the cabin and not under the car.

As an aside, last year to pass the MOT both handbrake cables had to be replaced due to stretch and the situation was improved to the point where it didn't occur, but it's gradually starting to happen again. So:

1. Does anyone know where the handbrake switch is located?
2. How do you get to it and what do you need to gain access? (along with intermediate parts removal instructions, if possible)
3. Anyone actually had this problem and fixed it? Tried and tested solutions welcome

I'm confident that once I can get access I can diagnose what's going wrong and make suitable "adjustments". I also suspect (but don't know) that the handbrake lever and switch is probably common to other VH models, like DB9. Thanks in advance for any help.

[Hutch525]

As it happens ive been doing handbrake stuff today,
So some pics.
Pull the leather cover off, only held in by velcro
The switch is down between the handbrake and the door

[bullet7]

If you intend to replace the switch, this is a generic type commonly used in Land Rovers and others. I bought a genuine Rover part as a spare and it was something like £12 or so. Rimmer Brothers currently have them at £15.

[LTP]

Hutch525 said:

As it happens ive been doing handbrake stuff today,
So some pics.
Pull the leather cover off, only held in by velcro
The switch is down between the handbrake and the door

Thanks Hutch - very helpful. It looks like you have the carpet out in your pictures, as my switch is partially obscured by the carpet. It also looks like you might have the lightweight seats, as my "fat" seat cushion seems closer to the handbrake.

But now I've seen where the switch is I could investigate mine a little further - I just folded the leather gaiter forward over the handle for this. The lever itself has a return spring (can be seen in your pictures at the lever pivot) but it appears that the actual part of the mechanism that operates the switch doesn't - and it's this part that doesn't seem to be sitting down on the switch plunger with sufficient force. (I've stolen your picture, and the part that does the work is indicated by the blue arrow). I can only assume that this part of the "lost motion" mechanism (that allows the lever to lie flat when the handbrake is on) relies on being pulled down by the brake cables, which must have return spring(s) on them somewhere.

To really investigate what's going on I think I'd need more room, which looks like it may mean seat out - not something I really want to do single-handed - or handbrake lever out; which probably means seat out first. It could just be that my handbrake lever inner mechanism is a bit stiff so whatever return springs there are for it in the system aren't strong enough to overcome the friction and pull it fully down.

I need to get the car out of the garage so I can open the door fully and really try to see what's going on and work out at what part of the switch plunger travel the switch signals to the car that the handbrake is off, but I could try gluing a piece of plastic a couple of millimetres thick to the top of the switch plunger to effectively increase its stroke. I'd have to be sure that this couldn't cause the plunger to "bottom out" and load up the body of the switch if the handbrake cables were adjusted, potentially breaking it.

edited to add
In fact I just opened your picture by clicking on it, opening it in another tab and zooming in and it looks like there's a piece of plastic about 1mm thick stuck to the tip of the plunger on your switch - you can see that it's a black square that's at a slight angle. So perhaps your car has had the same problem in the past and that's the fix? Can I ask what year your car is?

bullet7 said:

If you intend to replace the switch....

Thanks for this Bullet, but I don't think the problem is the switch itself - if the plunger is depressed then it seems to signal to the car OK. I'm guessing the electrical system relies on contact being made (plunger out) to signal the handbrake is on and lowering the lever pushes the plunger in and breaks the circuit. I need to get a multimeter on it to confirm all this, though.

typo fixed

Edited by LTP on Friday 24th September 23:28

[Hedged]

Perhaps not applicable in this case, but I had the same symptoms with my ‘14 Vantage and it was simply the leather handbrake cover interfering with the contact. Been 4+ years since w/o a recurrence.