since my mod is just the brakelights, and no Rear Fog issue involved, would you use a simple jumper, or that diode ??

 

You can use either. I recommend the diodes just in case you want to add rear fogs later on, but if that's completely out of the picture, a jumper is fine.

 

Yes, there is a heap of those drivers in the BC1. Here is a pic (click on it for a 2048x big version where you can read the part numbers for yourself!):


The main protection for these devices is the thermal protection; if there is too much current they get very hot then self-protect - if that happens they will either switch off (no lights) or pulse on/off (dim or flickering lights) depending on the design - I have not read all the spec for this particular part.
So trailer wiring could overload the device and trip its protection. There will be some difference in the exact trip point from one part to another; there is also the issue of the back of the PCB being bonded to the metal frame of the BC1 as a heatsink - if the bonding was not so good, thermal shutdown would be more likely if the device was overloaded.

 

Great Picture, thanks

On a NON MINI topic.
That board has a higher component density that the ECU I had to repair the power supply section on in my other car. There are 6 years of (NOT Seimens) ECU starting about 1992 used in over 50% of the worlds cars that used electrolytic caps that leak after 8 years. The engine stops because the electrolyte eats through the main B+ bus, or the fuel injector power bus. Lots of rebuilders will fix it for you for about $300. Your GM dealer will sell you a new ecu for about $800. All you have to do is replace the leaky caps (change every damn one), and bridge over burned out traces and the car runs just fine again.) It took me an hour to find the ECU up under the dashboard , about a half hour to get it out, and another half hour to fix it.

In my case half the board was engine ecu and half was transmission control, so if a car stops shifting properly this is a supect. I suspect the reason the anti lock brakes quit working was the same as a similar box for the brakes was located next to the ECU.

Hopefully the "German Engineering" specified decent parts!

OK lets all go back to (ab)using our cars!

John