Immobiliser issues - swapping the battery

[Lunja]

Hi all, we want to swap the battery from 91 mx5 into a 93 eunos with an immobiliser. Does anyone know if this will cause the immobiliser to activate?

It's a laserline immobiliser but we don't know what model.

Thanks in advance!

[Oldandslow]

Don't know. I'm assuming you have no way to turn the immobiliser off if it activates although I thought most of them activated every time the car's ignition was switched off.

If you're really careful and really brave you could change the battery with the engine running. Just need to be sure the positive lead touches nothing once disconnected. Tape a plastic bottle over it or something to make sure it's insulated. I've done it on other cars but they didn't have the battery tucked away in the boot.

[MX-5 Lazza]

Or use jump leads as if you were going to jump start the car. Attach the black to an earth point on both cars and the positive to the positive terminals then remove/replace the battery with the jump leads still connected. As above though, you still need to be very careful with the red positive cable.