Monday, March 30, 2009

Sneak Preview: Dome Light Module - A Modern Replacement and Upgrade

(Edit 04/13/09:  Added installation picture of 2nd prototype, and link to a draft version of the installation & programming manual, at bottom of this posting.)
(Edit 02/21/16:  Updated links for Dave's website of related products.)

Following this blog's theme of modern upgrades for the DeLorean DMC-12, I am pleased to announce that I and another DeLorean owner have been Beta testing a really neat device for our cars, a multi-mode replacement for the original Dome Light Module.
Solid State, Mode Programmable, Dome Light Relay.
The device is engineered by Dave McKeen (aka Bitsyncmaster on the forums), who previously re-engineered and currently sells a modernized solid state replacement for our RPM relays (reviewed here: "RPM Relay, A Modern Update". I have been using a breadboard version this new module, throughout our Florida Winter months, and have been offering Dave feedback and suggestions on functionality. For the most part it works great, and it is really neat (and cool) to have the light dimming functionality back into our interiors, when you utilize energy (battery) saving LEDs in the interior.
The original module was basically a timer circuit, to dim the interior console lights, but as it was designed over 25 years ago, it does not work with modern LEDs. The fix to this date has been to just remove the module (the white one in the fuse relay area), and the LEDs ran fine but in an on, or off, state.

(BTW: Picture above is the result of my fuse/relay area clean up project, from a few months back.)

In Dave’s re-engineered unit, the timed dimming functionality is back, along with a few other nifty modes.
Mode 1: OEM operation.
In this mode, the module behaves as a direct replacement module, where after 15 seconds of the doors being closed, the lights dim until they are off. With this module however, this feature works if you run either incandescent, or LEDs. (For a good reason to run LEDs, see here: "LEDs are Cool" ) Dimming and LEDs, are a near oxymoron, unlike an incandescent bulb that can be made to increase and decrease its light output with voltage changes, LEDs are either on or off at one voltage.
So How does Dave make them dim?
Techie answer: he seamlessly pulsates them until they dim off.
To the casual observer answer: Freakin’ magic.
Mode 2: OEM operation plus a 10-minute shutoff.
This mode is as above, but also automatically shuts off all interior (including door, bonnet, and engine bay) lights after 10 minutes. Although this is less of an issue with LEDs, it is a great feature if you are still running incandescent bulbs, in order to avoid excessive battery drain. With this module in this mode, I’ve driven to car shows, or have left the car open in the garage, and sure enough it becomes one less thing to think about when your interior lights are shut off automatically.
Mode 3: Parade Mode
This is a new and entertaining feature, this is basically Mode 1 but instead of the lights staying on, they blink on and off.  If you shut off the interior lights, then the effect is solely focused on the doors. This would be neat to run, say in a night time car show, especially with multiple cars, or as the cars drive by a parade, with the blinking door lights – talk about giving our doors even more of an airplane like wing look.
Mode changes
In order to change modes, you don’t have to go unburying the fuse/relay area. Instead you can program the module with the light switch from the glove box. As you program it, by pressing the light switch in a certain sequence, the unit provides feedback as to the new program through, interior light pulses.

Beta Version 2 (Pre-Production unit).
Right before I began to perform a DIY rear suspension upgrade on 2109, Dave shipped out the latest revision to the module (see picture below). Gone is the breadboard test unit, the latest version is dimensionally now closer to the production unit, where it would look like a plug in replacement, with some minimal wiring to ensure full and future support of features.  The workmanship is impressive on the scale that it has been done, with tiny surface mount components mixed along with some small chips, soldered on two stacked circuit boards - but you won't be able to see this on the production boards as it will be a solid, potted, unit.  As Beta testers, we are now switching our review and feedback to this new unit, so it may be a few more weeks until the module is ready for sales and general distribution. conclusion
Like Dave’s previous product, the solid state RPM Relay, this new module is a modern upgrade for aging, unreliable, and outdated electronic components in our cars. Dave has demonstrated to our small community that his products are reliable re-engineered components, and that he stands behind his product. This one is as clever and useful as his last, but this one is also just downright cool to see in action, as your interior LEDs dim.
I will post a small video later, stop by again to check them out. Thanks

To contact Dave about his upcoming Dome Light Module:
PM “Bitsyncmaster” on

Addendum 04/13/09:
The 2nd prototype has been installed and is working great. With some additional wiring at the time of installation, it brings some new neat functionality.  Below is a picture of the unit installed:

(Click on picture for a larger view.)

As previously discussed, the shipping version will be potted units, so it will look even better installed than the picture above.

Also, we've completed a first draft of the features, installation, and programming document. You can find it at DMCTalk.

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