02 T-sport Hazard Lights Have a Mind of Their Own

[gebe717]

I saved an 02 T-sport (Phase 1) from going to the scrap yard a few weeks ago. I have gradually been sorting the body out. I have got it to the point where I want to submit it for an MOT. However, the hazard lights keep coming on randomly, regardless of whether the engine is running or not. Pushing the hazard button does nothing. 

After extensive research, I have a few possible culprits. It could be the factory alarm. It could be the remote central locking system. It could be the flasher relay. I have also found remnants of an aftermarket alarm system which has been cut out. 

Apparently the Battery voltage going too low can trigger the alarm system too? 

The car will unlock with the key in the door, no trouble, and start. The key fob Battery is flat.

I did cut the green/orange wire going from the door control unit to the flasher relay. This fixed the problem, but then the hazards button did not work, so I remade the connection. 

I am at a total loss. Can anyone help me?

Cheers 😟

[MRichards]

I know barely anything about car electrics, but could you not remove the fuses of each of the components (i.e. remove the fuse that controls the central locking, then the one for the alarm etc) until the hazards don't randomly come on? I could be completely wrong (I prefer oily things to electrical work!) but an idea nonetheless.

[Mooly]

One known problem causing random alarm operation is the bonnet switch which is located at the bulkhead rather than at the front edge of the bonnet. All you need to do as a quick test is stick a thin piece of card under the bonnet so that it presses the switch plunger a fraction more. We are talking only a millimeter or two. Typically the bonnet contracts as it coils and the alarm trips. A proper repair is made by removing the bracket and filing the bolt hole elliptical so that you can move the bracket upward a fraction.  

This happened on my TSport in the early days.

If the wiring has been altered and aftermarket stuff fitted then anything could be going on but I would still check this as its an easy fix.