BMW K100 Motogadget M-unit Wiring (How-To)

This video describes in detail how-to connect your OEM wiring harness to the #Motogadget M-unit for a BMW #K100. Also other tips and tricks for a clean install of the total wiringloom. #tutorial
Please also check out the information down below:
BMW K100 M-Unit Wiring Diagram by Mikeyfrompiha
drive.google.c...
BMW K100 ORIGINAL Wiring Diagram
www.kbikeparts....
Mikeyfrompiha's rewire informational video
• BMW K100 MOTOGADGET M ...

[@davidmanchester2182]

This was a very well put together video. A must watch for those tackling the m-unit wiring on a K100. Covers the D+ connection for alternator charging, the cooling fan switch, upgraded (and necessary ground and postive/starter wires and more! Great job Sijard 🤙🏼

[@corner.custom]

Try my best to make the info as clear and complete as possible, especially for the important details like the D+ signal. Also the upgraded/thicker wires will help a lot with the start up of the bike 👍🏼

[@BayCityRestorations]

Excellent video brother! This should be very helpful for anyone looking to do and munit on a K100. The bike is looking killer too! Can’t wait to hear it fire up! 😎

[@corner.custom]

Thanks for the kind words buddy. Like you said, I hope a lot of people will benefit from this video. Time to bring her to life!

[@jawracing911]

Great job mate, although the lack of noise in the video had me questioning my device there for a bit 😝🤣

[@corner.custom]

Haha your device is perfect, only I got a notification from YT saying I used copyrighted music, so I first deleted all the music to be sure that was sorted. Now I'm busy replacing the flagged music

[@mikeyfrompiha]

Mate am loving that analogue speedo ! Can't wait to hear her fire into life !

[@corner.custom]

Thanks Mikey. The analogue speedo really fits in nicely with the overall look of the bike. Can't thank you enough for the diagrams, really makes this a walk in the park. Now it's full steam ahead to finish her and know how she sounds!

[@djojolegyptien]

Le travail de fou. Superbe. 👍

[@corner.custom]

Thanks 👍🏼🤙🏼

[@jurianrabie2451]

Hi mate, awesome work. I know this video is from way back. I can't find any info on BMW K-Series regulator rectifier chargers for changing to lithium battery. I have a K75 1986, just bought an antigravity ATZ10-AH restart battery. No clue if I also need a reg/rec? If anyone knows?

[@corner.custom]

Not directly needed, but recommended. Why skip on that part when you go that far. Better safe than sorry 👍🏼

[@csboi]

Why not keep the fan controlled by a temperature sensor on the motor?

[@corner.custom]

You can do that, but why not turn on the fan before it gets too hot when riding in traffic for instance

[@csboi]

@@corner.custom You can do that, but what if you forget to turn on the fan or turn on the fan after the engine is already a bit too hot?

[@michaelburgstaller3056]

Hello, I still have a question about the injection pump. When I use the keyless go function and turn on the ignition, the injection pump works loudly. In your video you can't hear the pump when you start the motorcycle. how did you solve it? I also connected the pump to the ignition as shown in the diagram from piha.

[@corner.custom]

Maybe you couldn't hear it, but it was running constantly with the wiring diagram used in this video. Mike from Piha made a additional video to his wiring harness video in which he put an fuel pump relais to it. Then it only pumps from the point when the start button is pressed. Check that video out and then it's all self explanatory. I check it, and it works 👍🏼

[@michaelburgstaller3056]

@@corner.custom thanks! ☺️👍

[@corner.custom]

@michaelburgstaller3056 Your welcome, good luck!!

[@twistedfatebuilds]

Great work Si 💪

[@corner.custom]

Thanks mate 👊🏼👍🏼👍🏼

[@ethaneckstein281]

Awesome channel I love your content!!

[@corner.custom]

Thanks, that's great to hear. There's a lot more to come soon!

[@kt-lg5md]

I'm working on wiring the m-unit on my k100. But when I turn my ignition switch on the charge light doesnt light up. It's a basic bulb (no led) with 2 wires. One wire to aux2 and the other to the blue wire from alternator. M-unit works, any ideas?

[@corner.custom]

The two wires from the bulb should be wired like this. One wire to the switched 12v supply (I took it from the ingition switch) and the other to blue wire from the alternator. It's been a while since I did this, please let me know if this solved your problem

[@CUMBREVALLE]

@kt-lg5md I am on the same boat. Did that work?

[@CUMBREVALLE]

@corner.custom the ignition wire you mention here is that the same as the ign-o in the m unit? So I have to tap into the one harness that soders all these wires?

[@corner.custom]

No with the ignition switch like mentioned above I meant the switched 12V supply from the key 👍🏼

[@CUMBREVALLE]

@@corner.custom thanks man! would the kill switch work as well? or just the ignition key cable?

[@Lexified_]

I’m at the end of my build and I just followed Mikey’s video on the fuel relay install. But I’m confused on how I wire my fuel tank. Where do I plug in the positive wire? To ignition output? Or to the fuel relay?

[@corner.custom]

There's a video on Mikey's channel on which he explains the part where you can make an change to the wiring like I did in this video. I believe you need to run the positive wire trough the fuel relay, but that's all mentiond in his video. Check that out and it will explain itself

[@rileymcconaughey6760]

I am having trouble with a brown and black wire, and a brown and white wire where the fuel pump connects into the tank. Do you happen ti know what those wires do? Great video!

[@corner.custom]

You can only connect the wires in the tank in one way due to the size of the connectors. The external connector to the tank has 4 pins, one ground, one powersupply and the two others are for the indication on the 4 and 7L fuel warning level. The green/white wire from the connector needs to be soldered up to one full wire like shown at @4:37 and then that wire needs to go in the IGN output

[@rileymcconaughey6760]

@@corner.custom can the fuel warning level lights be wired up? Or is it not comparable with the M-Unit?

[@corner.custom]

@@rileymcconaughey6760 It can be wired up, but then it will go around the M-unit, but that's ok. Just like the wire up on the blue alternator wire, that also goes outside the M-unit, but needs to be there to let the bike charge up correctly

[@rileymcconaughey6760]

@@corner.custom thank you very much. I have another question. Do you have any neutral indicator wired up? Or did you completely remove that?

[@corner.custom]

You can wire that up, but it depends on the speedo that you use. When it has a neutral indication light, I'll wire it up. For all my R builds I did wire it up, but on most K builds I haven't. Because of the speedo that I used. Off topic. I rather know the oil pressure than the neutral light, more important to know 🤓

[@Coffeeracershahbazz]

the bike looks good even without the body 😂😂🔥🔥😍

[@corner.custom]

Thanks Chief! I hope to show the end result soon 😁

[@AlbinoDyno]

Thank you for this, I'm about to start a similar project and this is the most informational video I've seen on this topic. Do you mind sharing what clutch and brake levers you are using?

[@corner.custom]

Awesome man, great to hear. I'm planning to put out more how-to video's. It's a Brembo | Grimeca | PS16 mm and the matching clutch lever

[@corner.custom]

By the way there's more detailed info on my IG page, Corner.Custom

[@AlbinoDyno]

@@corner.custom awesome, thank you!

[@corner.custom]

@AlbinoDyno Any time👍🏼

[@keithm7741]

Hi Love the video, this is a great build. Do you know how to connect the OEM ignition switch to the M-Unit. I have a red, green, grey & grey/blue wire. I'm only interested in getting it started but not sure which wires go where into the M-Unit. Any help would be appreciated.

[@corner.custom]

I don't know, but it is wise to make a small test setup with a separate battery and a light to see which wires are the switched 12V and the ground.

[@anaal121]

which seat is that (or where to get it). love the style of it

[@corner.custom]

It's a handmade seatpan which got upholstered by Miller Upholstery. I made up the design myself

[@DanukaLP]

Hi mate, nice work. How did u mount the aluminium plate to the frame?

[@corner.custom]

Bolted with 4 M5 bolts to the backbone of the frame. Just drill, tap the threads and done 👌🏼 Oh yeah and don't forget to put some Loctite on the threads as well 👍🏼

[@DanukaLP]

Nice, thank you. Do you still remember the size of the metal plate? I can't reach my bike the next days :D

[@corner.custom]

@DanukaLP I sold my last K100 two years ago, I think you'll have to wait a couple of days 😅

[@rubengonzalez9682]

Any links for handlebars, brake master cylinder, clutch levers you used on your build? Or a parts list used in the video?

[@corner.custom]

Handlebars are from caferacerwebshop.com and the other parts from motolab.com, Brembo Grimeca. Don't have a full partslist sorry

[@rubengonzalez9682]

@@corner.custom appreciate the response! Thanks!

[@corner.custom]

@rubengonzalez9682 you're welcome buddy 👍🏼

[@Bornamortezaei]

Sehr interessant 😅 Out Light to Brown Motoscope Pro ! Wenn das Licht eingeschaltet habe wird das Tacho aus !!! 😂 Brown soll in AUX 1 or 2 eingeschlossen werden!!!

[@corner.custom]

Ok thanks for the feedback 👍🏼

[@g.b.7990]

Great location for the wiring, how thick is the aluminum plate u use?

[@corner.custom]

Thanks. I've used 3mm. The plate isn't that large, so it's nice and stiff 👌🏼

[@ClintPrior]

Where did you get the little incandescent light from? Do you have a link?

[@corner.custom]

If you Google the part number that's on it, you'll get a hit on the RS components site 😉👍🏼

[@clintprior9989]

@@corner.custom I tried that but didnt get any hits. but the RS components was enough of a hint to get some hits. legend thanks

[@andreasedlinger7621]

nice work :) the place of the electic is nice, but isn´t there a problem with rain/water?

[@corner.custom]

Thanks 👍🏼 I've kept some space between the plate and the frame 👌🏼

[@andreasedlinger7621]

ok perfect :) another question, the electric plan shows that the fuel pump is direct connected to the ignition. so when you turn on the ignition the whole time the pump runs? isn‘t it?

[@corner.custom]

​@@andreasedlinger7621 Yes correct. The fuel pump stays on as soon as you turn the M-unit on. It is so that when you switch off the engine, the fuel pump also switches off, even if the m-unit is still on contact. When you start the engine again, the fuel pump starts again automatically. On my next build I think I will use the OEM relay so that the fuel pump only kicks on when you actually start the engine

[@leonardfrank2949]

Which exhaust do you have? Nice work 👍

[@corner.custom]

I've shortened the original pipes, the collector comes from BSK and the damper is from Aliexpress at the moment. Had a hard time finding a decent one, so this will do for now.

[@leonardfrank2949]

Yes, im searching too. I will try one from leovinvi, after Electric project.. 😁 Thanks for quick reply. Greets from germany.

[@corner.custom]

@@leonardfrank2949 Sounds good! No problem buddy, good luck with the search

[@user-qe9wo3mf1u]

what kind of exhaust dud you installed and won did it affect the engine power ?

[@corner.custom]

I've shortened the original pipes, the collector comes from BSK and the damper is from Aliexpress at the moment. Had a hard time finding a decent one, so this will do for now. The shortened exhaust will help for better flow/less restriction. In combination with the open air filter and the new 4 point injectors, the engine will feel better than the original. Probably going to do a dyno session to measure the difference. There will be a specific video about that

[@samuelbakos39]

Awesome video, I was working through a rats nest of wire and trying to figure out how to clean it up (despite being an electrician). Do you have links for the mount in stem start button and fan switch? I've asked powerbrick about where they get it but haven't gotten a response.

[@corner.custom]

And I'm not even a electrician haha. I had to drill out the stem to make the button fit though and also had to tap thread into the stem. I bought it online from RS-Components but can't remember the part nr. The fan switch was just a simple switch from a local store

[@martingladwell7970]

? Are you based in the UK 🇬🇧 , also any chance of getting a copy of your video sent so easier to view . Regards Martin. Looking to build a flat track version.

[@corner.custom]

Hi Martin. I'm based in The Netherlands. There's a download function on YT to download the video. Good luck with your build👍🏼

[@boomhour1976]

Nice video Sijard, love the digrams. Does the black and yellow wire from the ECU get connected to anything? looks like the fuel injection black and yellow goes straight to the starter relay and then to the munit start output?

[@corner.custom]

Thanks man. There are two wires that go in the starter output of the Motogadget M-unit, the black/yellow from the starter relay and the black/yellow from pin 6 from the ignition module. The link to the full wiring diagram is in the description of the video

[@user-bj8db5lx4n]

@@corner.custom the reason I ask is that I have it all hooked up that way but I don't get a spark at the plug when I hold it up to a grounding point. Not sure if that is an issue or not but I've seen other videos where this is done as a test to verify correct wiring.

[@corner.custom]

@@user-bj8db5lx4n Ok and how did you connect the ground wires? Did you had any spark before you started working on the wires? How did you connect the 4 into on wire that goes into the ING output?

[@boomhour1976]

@@corner.custom I have 12 volts at the coils with ignition on at both the front and back of the coils. the ground wires from the coils are just tied into a common ground on the frame.

[@corner.custom]

Ok and how about the other things I've mentioned before. Did it ran before, IGN output?

[@nxlax16]

No choke?

[@corner.custom]

No it isn't directly necessary

[@swavecb]

Why switch for fan?

[@corner.custom]

Because I don't see the point of getting the engine to such a high temp before the fan would be switched in by the relais. You'll know when to cool the bike when running so you can already manual switch the fan on to prevent it. Also there wasn't a lot of room left for the big temp relais

[@andreasedlinger7621]

@@corner.custom thought the temp relais is also for the injection control, but I think you are right. Wouldn´t it be possible to conncet the now free temp sensor with the speedo (i use a motoscope pro)?

[@corner.custom]

@@andreasedlinger7621 The temp sensor I the housing is essential for the ignition of the bike, the relay isn't. I haven't used a Motoscope before so can't help you with that, sorry

[@mruniverse5704]

Is it compatible with k75 bricks?

[@corner.custom]

I do believe so, but haven't done this on a K75 before so don't know for sure

[@mruniverse5704]

@@corner.custom thanks 🙏🏼

[@corner.custom]

@@mruniverse5704 Your welcome 🤙🏼

[@luissalgado8464]

Will this work or be similar to a k1100?

[@corner.custom]

I'm not 100% sure, haven't done a K11 before. I wouldn't be surprised if there are some minor differences, but 90/95% will be the same IMHO

[@luissalgado8464]

@@corner.custom Thank you so much for the haste response! Great video and descriptions, you have given very valuable information ! I feel a little more comfortable starting my K bike journey.

[@corner.custom]

@@luissalgado8464 Sometimes you just have to start and continue from there. You'll be alright 👍🏼

[@jacobl7899]

I jumped the gun and tossed out my entire oem wiring harness 😪🥴

[@corner.custom]

No succes you mean? What kind of bike do you have?