Land Rover Repair: problem after resetting Service Engine light, inertia switch, independent mechanic

Question
I have a used 1997 Discovery.  The Service Engine light came on at the 82.5K mark.  My independent mechanic did the req'd service and reset the switch.  When he put everything back, the flashers came on (and can't be turned off w/o disconnecting the battery) and the door lock system will not work.  I noticed on http://www.discoweb.org site that the illustration says that the ignition should be on when doing the resetting process.  If my mechanic kept the battery disconnected while he was doing the resetting, could that have effected the other sytems?  His computer shows no error codes from the vehicle.

Any experience with runaway flashers, etc?

Al Benas

Answer
Hello Al,

this sounds like you've affected the alarm system.  Flashers activating and door locks not working is the key here.  

Can't be the inertia switch...that would trigger flashers but also cut fuel from engine.

Here's what you can do:  as soon as the engine is started and the flashers begin there thing, quickly turn the engine off and then turn the ignition key back on as quick as you can.  Turn the key just to the point BEFORE the engine is turned over.

You can try this with the doors locked and if that does not work, try it with the doors unlocked.

You can also reset the fault codes by disconnecting the battery for about 4 seconds and then reconnecting.  Turn on the radio CD and enter the security code.  Reset your clock too.

Hope this helps...otherwise, take it to your LR dealer and have them reset the alarm unit.  Its a flaky spider unit and alarm ECU that causes Disco owners all sorts of strange problems.  This is the first I've heard of this problem.

Best of luck,

JohnMc