Project 1 - E30 Dome Light Delay Retrofit

[berserkdroid]

Firstly, gotta convert the stock 318 to be able to use the delay relay as per this link:http://www.e30zone.net/e30zonewiki/index.php/Retrofitting_Interior_Light_Delay_UnitSo got that done on one side for test purposes, now the cabin light stays on then turns itself off after the door is closed. Thought I'd try putting in an Op-Amp dimmer circuit as well so that the dome lights dim to the "off" position as per this thread:http://www.mp3car.com/vbulletin/hardware-development/62668-dome-light-dimmer-delay.htmlGotta admit, it does look cool. But this is where my first stumbling block has arisen. You see, this setup has a conflict with the existing Cobra Alarm system in that until the lights go to the "off" position completely, the alarm system thinks that the door is open and will produce a series of beeps... :banghead:Btw does anyone know what the blue relay in the attached pic is for? Its situated directly above the glovebox with its own socket, and produces a click everytime the door is opened/closed, so i'm guessing that it may be somehow connected to the OEM alarm system? Can't seem to find it in the manuals...

 

[pussy]

thats the relay for the indoor lights which also connects with the door switch..

 

[berserkdroid]

thats the relay for the indoor lights which also connects with the door switch..

But when I pulled the relay out the indoor light functioned as normal, ie "on" when the door was open and "off" when the door was closed... :questionmark::questionmark:

 

[berserkdroid]

Dimmer Test 1:

 

[mizhan]

cool project :top:

 

[berserkdroid]

cool project :top:

Thanks mate. Once I sort out the interaction of the unit with the alarm I'll expand it to work on all doors. As it is the delay circuit only works on the drivers side (as BMW originally intended) for now.

All in all, its been pretty cheap to build but takes some doing with Copper boards and etching solutions.. ick!