I am researching for a couple of electrical projects, such as adding fog/driving lights and auxiliary horns onto my R53, and I have a few questions for you electrical geniuses out there. Please keep in mind that I am a neophyte when it comes to electricity/electronics. I can tell you everything involved with email, from the client, through the MTA and out to the internet. But for electricity? Thats pure voodoo there!!

1. How do I determine the nominal electrical load for an 06 R53 where the rear defogger is not on, but the HK radio, headlights, and auto air are on? I know that the alternator maxes out 105 amps. The headlights I'm thinking of using are about 5 amps each, whereas, each truck horn from Stebel requires a 20 amp fuse!! Therefore, I'm guessing that I'm gonna need a relay for the lights and another for the horns but will have to plan on adding a total of 80 amps for these two projects. Is that even close to being right?!?

2. My wife wants me to use another toggle panel for these projects and I cannot find information about the feasibility of re-using an OEM switch to this end, independent of the wiring bus. I'd like to mount it below the existing bank. Any suggestions/links for this?

I do thank ya'll for your input and apologize before hand if this is "old territory". The search function does not allow for word proximity searches nor booleans. Sorry...

Cheers!!

 

1. I'm no expert, but unless you've got all the lights on and lay on the horn continously, you should be OK. If you outdraw the alternator, you're just pulling current from the battery.

2. Sounds like you need to talk to Ian Cull (GBMINI) - his autoup circuit intercepts and 'translates' the signals from the OME toggle rack. He might be able to create a custom circuit for you.

If this comes to fruition, let us know! I've got enough add on electronics that I've thought of using a secondary toggle rack as well.

 

Start at the device (lites, horns) and work backward -it's safer. I'd recommend at least one 30 amp relay for the lites, and one 60 - 80 amp relay for the horns (it never hurts to go too big). Fuse them all - between the relay and the device - and use reasonably heavy wire (I like 12 gauge, but that may be overkill for the lites), then shop around for an add-on panel to put switches in to energize the relays. Remember: Momentary On switch for the horn!
One reason for the big fusing on the horns is because they use electric motors to drive the pumps. Electric motors have a high startup current, and running a compressor (for the air horns) uses mucho power.
The OEM switch panel is NOT something a newbie (or even a reasonably experienced DIYer wants to mess with. It's not designed for easy modification.
The Mini's system should handle these loads easily (unless you're planning on playing the long version of "Heard It Through The Grapevine" on those horns...)

 

Skip, thanks for the input. Here's another question for you. How about if I were to use the front of the toggle panel but not the back, the etched board? Or is that gonna be too complicated?

Cheers!!

 

PB, somewhere on NAM is a post about adding to the switch panel, something about modding the auto down/auto up for the windows. The pictures show how tight the area is in the panel, and it's not just a question of popping off the cover, drilling a hole for a new switch and putting it back together.
One possibility, at least on my '02, is to use the two spots on either side of the tire monitor reset switch below the handbrake. It's an easy area to get to, with lots of room. I'm thinking something on the order of pushbutton switches rather than toggles. If they were the lighted kind (light when on) it could look pretty cool.
Not sure if your 06 has anything similar, tho.
I'll see if I can find the window mod thread for you.
****Found something better:
>>go here: Sticky: Install Guide: R56 Rear Fog Light Retrofit

Check Wolfshiem's .pdf file for some useable ideas and great photos.

 

In case you haven't seen it:
http://www.gbmini.net/wp/2005/04/ins..._switch_panel/

The issue with using the toggle switch panel for new circuits is that the switches really aren't switches at all!
They are plastic pieces that press a conductive rubber mat on to PCB traces, giving a signal but at very low current - not enough even to turn on a relay!
You have to have electronics between the switches and whatever you want to control.

 

Great point, GB. With that type of switchery -keyboard, calculator, etc.- it would be far easier for Poppa Bear to get that extra switch panel he was looking for, gut it, and install toggles that match the originals. Then mount that one under the first panel.

 

Fellas, thanks for the input. I'd actually seen Ian's switch mod back in the day. It was that information which gave me the idea to use an OEM switch for this project. My wife insisted that..., erh, I wanted to use OEM toggles instead of these Radio Shack switches. I had planned on surface soldering onto the switch leads that would then connect to the relays. But, if I'm understanding ya'll correctly, there isn't enough voltage crossing the pads to activate an automotive relay? In order to use the OEM toggles, can ya'll give an idea as to what electricalicity thingys would be needed? I'd rather not make this deal too complicated, however, I would like to evaluate the options against my minuscule skills to determine if it'll be worth it in the end.

I do appreciate ya'll's feedback and look forward to hearing back, thanks!

Cheeers!!

 

You need some sort of electronic buffer circuit between the factory toggles, and your circuit.
If you can "diy" a circuit, it's easy.
I could create some sort of interface PCB, but it would probably cost $100 or more!

Some searching on the web led me to these links, which are for a PCB that you could use - see "kit 74" here:
http://www.kitsrus.com/kits2.html
One place to buy it - looks like OK price - is here:
http://www.electronickits.com/kit/co...lec/ck1601.htm


I have NO experience with this kit or the suppliers - but using a ULN2803 to interface between the toggle switches and relays is a very good way to go, and the $40 price ASSEMBLED is pretty reasonable, especially since it includes 8 relays

 

Something else just occurred to me.

The toggle switches are, as we know, momentary; not latching. They are "on" while clicked and "off" again when you let go.
With a circuit like above, the relays then would be on only while you click the toggle.
You want instead want an output that "toggles", turning on when you click a toggle, and off when you click again - but staying on/off in the meantime.

 

I want to do the same thing as Poppa Bear, using a second back to control lighting. I have no skills what so ever in this area. So i buy this kit and then what?

 

GB, I really do appreciate your advice here as I know this is your forte. I don't think that I understand enough electralicity theory to get how a relay works. So, when the Radio Shack switch is thrown, it maintains contact which subsequently enable the relays, whereas the toggles only briefly touches contacts and hen disconnects, right? How would I change this behavior/effect?

I'm not trying to build my own nuclear power center control room here but am still intrigued enough to find out if this is a "doable" project. Thanks again for ya'll's advice and suggestions.

Cheers!!

 

You're right.
When you push the radio shack switch, it stays pushed. But the toggles go back to center(=off) when you stop pushing them.

So you need something that changes from off-to-on when you push a toggle, and stays on (like the radio shack switch), till you push the toggle again.

There are such things as latching relays for special applications, but expensive ... the better solution is some electronics that does the "stays on" stuff.

 

Sorta like your auto-up windows, right?

Cheers!!

 

GBMINI,

As I am completely lost with electrics and electricals, an office mate, who is a UK (RAF) Electrical Engineer and intrigued with my ambitious plan, is willing to teach/assist me with this mod. In order to minimize the amount of discovery learning, do you have either a wiring diagram for the toggle panel or perhaps a link to one?

Keeping in mind Rule #1 for my MINI (Must not hurt Maggie!!), Steve's going to advise me on how to go about this project. I hope, along the way, to pick up a rudimentary knowledge of DPST control relays, amps, resistors, etc. and any assistance you could provide would be greatly appreciated.

Cheers!!

 

Send him to my auto-up windows pages, where he might gather some info ...
http://www.gbmini.net/wp/auto-up_windows/diy/
In particular, the schematic has the connection pins labelled.
http://www.gbmini.net/MINIcircuit/MINIcctSchematic.pdf