The Magna Headlamp FAQ:

[vlad]

Hi All, blew the drivers side low beam globe in my TF exec the other day and used the opportunity to order a set of Philips X-Treme Vision H4's which arrived today. Drivers side replacement looks pretty straight forward by removing the washer bottle, but the passenger side is going to be a bit more complicated, as by reading back a few pages on this thread (also confirmed by a quick look under the bonnet), the battery and fuse box need to come out.

My concern is the last time I replaced the battery myself, I left in disconnected too long and the engine management computer re-set itself and had to go to Mitsi's to get it set up again along with a throttle body clean, which I want to avoid doing again.

My question is, what's the best method to maintain voltage to the computer, whilst removing the battery to change the headlight globe?

Thanks for any help you can provide.

I did mine by moving the fuse box out of the way and disconnecting the battery. Should only take a few minutes. Can always use a spare battery to run to the cables. That is, connect +ve from spare battery to the +ve lead in the car and connect the -ve from the spare battery either to the -ve lead in the car or engine block. You then disconnect and remove the battery. If you don't have a spare 12V battery then two 6V batteries in series (ones used for lanterns) will do.

[rakhurst]

Cheers for that Vlad. Good advice. Just got to see if my jumper leads will reach across from the missus' car.