Joe, Very nice write-up! It is nice to have someone take the time to present such a detailed description. If I may add a few thoughts. The "proximity switches" come in 3 types, the most common is "form A" which is closed circiut in the presence of a magnet (and most common because they are used in alarm systems). Then there is "form B" that is open ciruit in the presence of a magnet (good for door switchs since they draw no current when the door is closed). "Form C" has both open an closed circuits (3-wire SPDT). I built a similar circuit for my car and wanted to share a few things I learned. With normal bulbs, the D's door lights pull about 1 AMP each side. It is abut 1/10 that or 100 mA with LEDs. The typical magnetic switchs is rated for 500 mA for form A and 250 mA for form B. So, it is probably good that you used the transistor. I used the form B switch with a relay so I could do the function of both of the driver's side switches with one magnetic switch. The down-side of the relay is that you have to wire it to a power source under the dash (only used when the door is open). It would have probably been simpler to use a transistor like you! I too, really like the results. I never have to worry about the switch alignment again. There is no contact between the magnet and the switch. Again, I appreciate the write-up. tom To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/