Bonnet Sensor Problem

Hi guys

10 minutes ago my car alarm went off so I rushed out to check on it and all appeared fine. However when turning on the ignition I noticed that the bonnet warning light was flashing, indicating that it was open even though it wasn't

I've had an issue with it for a number of months since having the bonnet resprayed. Sometimes after closing the bonnet, I would still get the flashing warning light indicating that it was open - usually re-opening it and closing it again would fix it. I'm not sure if the bodyshop removed the bonnet to do their work, though I'm presuming they did and thinking that maybe the sensor isn't aligned (or something like that!?)

The bonnet catch is also quite sticky. Sometimes when pressing the catch it sticks in the open position, rather than springing back like it's supposed to. I've put WD40 on it which has improved it slighty, but it still isn't completely free

I just want to know if anybody else has had a similar problem and how they fixed it!? I'm also curious as to how the sensor works - is it a button that gets pressed when the catch closes down on it? Maybe it's grimed up like the catch?

(The alarm has just gone off again since starting this thread, so I've had to disable it for now)

Any help appreciated, thanks

Also maybe worth pointing out that to open the bonnet, you've got to give the lever inside the car hell of a pull. It doesn't pop open easily like it used too


Would a garage look into this? Or would they not bother because it's not strictly mechanical!?

Thanks for your help guys

Tried WD40 on the lock mechanism and it didn't improve things

So I removed the lock mechanism and unclipped the microswitch. Now I don't know whether I done this when removing it, or whether it was already like it, but the plastic clip holding the microswitch into the locking mechanism was snapped. My theory is it was already snapped and as a result fitting loosely into the locking mechanism - maybe enough so that the microswitch wasn't being depressed when the bonnet was closed

Anyway, I've bodged it for the time being by wedging the microswitch into the lock mechanism. Problem now is that the bonnet is showing closed, even when it's open.... But at least that doesn't set the alarm off!


Either way I will need a new microswitch because of the broken clip, so my question is whether I can buy the microswitch WITHOUT having to buy a complete new locking mechanism? Also, if so, how difficult is it to fit the new microswitch? It was getting dark so I was struggling to see where it's wire runs. I'm hoping I don't need to remove loads of things just to route the new wire

Sorry to bump this, just hoping for answers for the above? Cheers

I got that impression from the initial replies in this thread, but after removing the mechanism and unclipping the microswitch with relative ease, I figured they may be considered two separate parts and that I could maybe get away without buying a whole new mechanism. But no problem if they're not! Thanks


Now, where does the microswitch wire run exactly? I'm guessing there's a connector block somewhere where it plugs into the main loom.... but I can't spot it!?



(Pink - bonnet release cable. Red - Locking Mechanism. Green - Microswitch cable)