Having been rear ended in two other cars both much larger than my MINI, not sure why I didn't do this sooner......From factory, every 2002-2004 MC and MCS top bulb socket in each brake light housing is dormant with no pw to the bulbs...ready to be activated.

The Cost was $1.49 for two diodes from Radio Shack.....Nice addition to my rear 3rd brake light flasher too.

 

OK, how did you do it? What did you need the diodes for?

 

I had done this to mine for a bit. I used some wire to make jumpers for the bulbs, but I undid it awhile ago because I liked the understated elegance of the rectangular brake light and the fog lights were about twice as bright. It seems your radio shack diodes leveled the brightness.

 

Radio Shack part number 276-1141, from drawer trays in isle. They are black with ONE silver band. $1.49 for the pair. ( Two come in a bubble pack )

The diode acts as a one way switch and prevents power loss and spikes to the bulb extending the life of the bulb. And if you have rear fogs now activated by the dealer, you will have the benefits of both. I bent each end down 90 degrees and used it as a jumper to go from one wire socket to another for each of the two rear light assemblies. Just go in thru side hatch panels, unplug the square sockets and insert the diodes. Just make sure the cathode side goes into the # 1 wire sockets. ( that is the side with the silver band )

That is all there is to it - a piece of cake. Great mod for the buck.



go here to C3 for more detailed instructions: http://www.littlemini.us/technical/brakemod/index.asp

 

Diodes aren't strictly necessary for this mod, and they will drop the voltage by about 0.6V, but they never hurt.

When you would *really* need the diodes would be if the car had functional rear fog lights. With only a simple wire jumper between the fog lights and the brake lights, not only would applying the brakes turn the fog lights on, but turning the fog lights on would activate the brake lights as well, which you don't want.

Using diodes allows the brake lights to turn on the fog lights without allowing the fog lights to turn on the brake lights.

 

Right-o, forgot to add that, since some may have already activated their fogs and switch banks.

 

You need to be careful with this mod as there have been numerous cases of this mod being blamed for a BCM failure. If you want a better alternative you can actually just swap the leads and have the fog light activate for the brake lights and have the lower one for running lights. This way it doesn't subject the BCM to any additional voltage.

 

The OEM rear fog in mine has no avenue to send voltage anyplace else ? And the diode is a one way switch preventing power backlash.

If you use a paper clip or copper wire, i can see how THAT would be an issue though.

 

The concern is that rather than the BCM only having to provide enough current to illuminate the brake lights, after the mod it has to provide enough current to illuminate both the brake lights and the fog lights. This is true whether you use a jumper wire or a diode to make the connection.

If you wanted the same result without putting any significant additional load on the BCM, you would have to use relays to power the fog lights from the battery, and use the brake light wiring to activate the relays. The coil in each relay only draws about 1/6th of an amp, so the setup would only draw an additional 1/3 amp from the BCM.

 

Great...........

Guess it's off to Radio Shack or the auto parts shop for some more parts..........Hopefully it should still end up being a decent mod costing less than 5 bucks though. I'll take pics along the way and have this mod updated.

 

Another way to make this mod safe is to replace the fog bulbs with LED. They draw little power and would be easily handled by the BCM. However good LED bulbs cost a lot more than $5 each.

 

Since this post links to one of my pictures of my rather defunct personal MINI site, not related to my c3 (Cooper Club for Charities)...this was a mod that was popular among first gen owners in 2002-2004. While there were reports of some BCM failures, there were also many more people that had no issues for years. I ran mine for 3 years without issue--from 2003 to 2006 as did hundreds of others.

Richard

 

Richard is correct.
I bought my car with 8400 miles on it, and this mod was one of the first few things I did.
My car now has 82,000 miles and I have not had any issues at all with it...and I used a paper clip.

 

But there are still a lot of folks that had one go bad. A co-worker had his replaced because of this. Fortunately he removed the mod before going to the dealer.

The possibility is there and the BCM is not cheap.

 

Well the way I see it, is that any mod you do has a potential risk especially these DIY type. When we were modding our factory nav software, a certain percentage of people also killed their units because the firmware upgrade failed, or they did something wrong during the process. A large percentage of us got to experience the latest BMW X5 software in our MINIs and some ended up having to purchase new DVD units.

For any DIY mod that hasn't been engineered, you take your chances and weigh the risks versus rewards.

Richard

 

I've been using the diode for mine for from 45000 miles to 77000 miles without an issue. Good safety mod so that others are more aware that your MINI is on the binders.

 

Is the problem only with those who also have rear fog lights?

 

When adding a wiring harness for a utility or boat trailer....99% of the time these are used: Hardwired directly from a OEM rear housing wires.



And the lights in these trailers are drawing 5-8 AMPs for turn signals ect.

A brake light bulb in a MINI is drawing what - maybe 3 AMPS ?

Not exactly sure how this mod is any different than adding a trailer connector ?

If so, maybe someone here can explain.......

 

If fogs are the common link it would be good to know if your co-worker had OEM rear fogs activated or not ?

Info may help us to establish a link for the purported failures.

Can you find out ?

Thanks.

 

Those generic "tap kits" are still in widespread use because they're what most people grew up with, and for most vehicles (including modern ones) they still work.

In older cars, the lighting system just consisted of fuses, wires, bulbs, mechanical switches and mechanical flasher relays. You could add extra lights, and as long as you didn't exceed the current-carrying capacity of the wires or the fuses, you were fine.

But in many modern cars, the lighting systems are computer-controlled and computer-monitored, and you can't automatically assume that you can increase the current draw without running into problems. If you look at websites that sell trailer lighting equipment, many of them recommend "lighting modules" (which are pretty much just relay packs) to isolate the additional lighting from the car's factory lighting wiring.

For any particular car, perhaps the engineers designed in a "fudge factor", and you can safely add extra lights to the stock wiring, but for the price of a few relays, why take the chance?

 

I think these rear brake kits are sold by some vendors here. Wonder what those "Kits" consist of for a mere 15 bucks.

And if a 40 dollar module is all that is needed, and just hook it up to the battery and brake lead - IMO that would still be worth it .

Thanks.

 

I don't know what's in the vendor kits, either. If it's just a pair of diodes, they're wildly overcharging, but $15 would be a fair retail price for two diodes, a relay and some wires.

I'm a big fan of relays in general, because you don't have to worry about exceeding the capacity of the car's wiring, no matter what you install. Want six driving lights on the front of your car? Use a relay and some heavy-gauge wiring to the jump-start terminal under the hood and you're all set. 140 dB air horn? Same thing.

Relays are also cheap and *extremely* flexible. With a couple of standard SPDT Bosch-type relays, you can make a latching circuit (one pulse energizes your accessory, and the next pulse turns it off). You can use them to convert a positive signal to a negative signal or vice versa. You can use them to convert a pulsed output to a constant output. I've even used them to remotely switch subwoofers from a series configuration to a parallel configuration and back. You can even make an entire car alarm, complete with flashing lights, siren and door monitors with just relays and a few ancillary components like pin switches, resistors and capacitors.

 

I did this on mine as one of the first mods to my car, and i LOVE the way it looks now. Don't think it really helps people to stop further back though; drivers are kinda crazy where i live.

 

The cars I were reffering to DID NOT have the rear fogs activated. Doesn't make much sense to have them activated and try to use them as additional brake lights.

The mod I was reffering to is still the safest one. The lower lights are the running lights and the upper rear fogs are now the brake lights. A little higher and a bit brighter than the dual bulb. And no possible problem with the BCM.

 

Can someone who has done this check the change with a meter to see what the increase with the diode actually is over OEM?