M-unit wiring.

Discuss everything about Honda GoldWing. Feel free to ask any question related to GoldWing.

Moderators: CYBORG, Oldewing, robin1731, Forum Moderators

Post Reply
MegaDan
Titanium Member
Titanium Member
Posts: 373
Joined: Mon Jul 25, 2016 11:05 pm
Location: Omaha, NE

M-unit wiring.

#1

Post by MegaDan »

This mainly has to do with utilizing the factory switch gear with the M-unit. I have an M-unit Basic, a Blue without the bluetooth, coming in the mail. I am working on laying out a plan/diagram, but I don't have the greatest confidence in my grasp on how I should setup the switches. So if you feel like tweaking, critiquing, or suggesting any changes to my plans, or if you simply think I am on to something, feel free to let me know.

I am going off of this diagram: http://www.wiringdiagrams21.com/wp-cont ... iagram.jpg

If you are unfamiliar with the M-units switching function, the input circuits are independent circuits that trigger the M-units programming for the outputs when the circuits are completed. So the switch wiring needs to function differently from the factory diagram.

Turn signal switch: Gray wire (second from left) becomes my ground, with the inputs for the left and right being the orange and light blue. I have a plan for making it a momentary switch by removing the little spring and ball bearing that catch in the detents, and utilizing the built in Auto-off timer of the M-unit, which is 30 seconds after the brake switch input is deactivated.

Headlight switch: Blue and white wire is now the ground, with white going to low beam input, and dark blue going to high input.

Brown and white wires coming out of both are for gauge lights on a fused circuit and can be eliminated from the switch and tied into the headlight circuit to activate.

The white/light blue and white/orange are the power for the running light circuits, which can also be tied into the headlight circuit. I may have to use a bridging diode between the low and high beam to ensure they stay on. Since all of my lights are LED, the current draw can all be handled by the wires with ease, and that really simplifies things. (plus the headlight circuits are rated to 200W...)

The ignition, kill, and starter switches are the easiest ones to figure out, so I don't even need to think much on those.

I still have some other details to figure out, such as how to run power to the fuel level and temp gauge. I may be able to run an Aux output to the 7v regulator, which I can also tie off for my 12V switched power to my Microsquirt. At this point my brain is kind of mushy, so I am going to set it down and walk away.

Feel free to leave any input, I welcome all insights.
1975 GL1000 - Delkevic exhaust with stainless studs, Corbin Touring seat, Race Tech Gold Valve cartridge emulators, Progressive 11-1100 springs, Progressive 412HD rear shocks, Shinko 230 tires, Fork Brace, Trucklite 27270c headlight, X-Arc Signals (run, brake, turn), Hydraulic Clutch conversion, EBC Clutch discs, HD springs, and Barnett Steels + Plate B eliminated. BikeMaster DLFP-50N18L Lithium battery, Rick's Motorsports CBR600F4 Mosfet Regulator/Rectifier upgrade.
User avatar
Easter
True Blue Steel Biker
True Blue Steel Biker
Posts: 2999
Joined: Thu Sep 13, 2012 11:33 am
Location: South of Houston 100 miles

Re: M-unit wiring.

#2

Post by Easter »

I used the M-unit on my "dumpster build" and was glad I did as it was a big improvement over trying to wire in a conventional way but it does require a different mindset. Are you using the M-button? it is relatively cheap and reduces the number of wires running from front to back. I did not use the stock harness at all and think you would find it simpler to start with a clean slate. The only wires attached to the stock ignition switch are the two "hot" wires from battery back to the M-unit.

I am something of a minimalist when it comes to building these old bikes so my wiring is much less involved than would be required with turn signals and safety devices like clutch and side stand switches, etc. Still, it is probably a good idea to use a small fuse panel on the output of the "accessory" connection since you will be connecting multiple wires to it and while the fuses are not mandatory, because the accessory circuit is fused internally, the extra points of connection will be needed. I found it helpful and simplified my wiring to use a long bolt on the coil to frame bracket and just bring all my grounds from the front half of the bike to that one point and stack the connections on the bolt, one above the other. The other ground point is on the M-unit itself for the back half of the bike.
Bikes at present:

83 XL 600r with a 2004 XR650L engine
And a slightly worse for the wear BMW GS adventure bike awaiting repair
83 GL in process :IDTS:
MegaDan
Titanium Member
Titanium Member
Posts: 373
Joined: Mon Jul 25, 2016 11:05 pm
Location: Omaha, NE

Re: M-unit wiring.

#3

Post by MegaDan »

Easter wrote:I used the M-unit on my "dumpster build" and was glad I did as it was a big improvement over trying to wire in a conventional way but it does require a different mindset. Are you using the M-button? it is relatively cheap and reduces the number of wires running from front to back. I did not use the stock harness at all and think you would find it simpler to start with a clean slate. The only wires attached to the stock ignition switch are the two "hot" wires from battery back to the M-unit.

I am something of a minimalist when it comes to building these old bikes so my wiring is much less involved than would be required with turn signals and safety devices like clutch and side stand switches, etc. Still, it is probably a good idea to use a small fuse panel on the output of the "accessory" connection since you will be connecting multiple wires to it and while the fuses are not mandatory, because the accessory circuit is fused internally, the extra points of connection will be needed. I found it helpful and simplified my wiring to use a long bolt on the coil to frame bracket and just bring all my grounds from the front half of the bike to that one point and stack the connections on the bolt, one above the other. The other ground point is on the M-unit itself for the back half of the bike.
I am not using any of the stock harness, except the existing charging system wiring, which was already gone over and improved when I did my mosfet reg/rec upgrade. I actually have a complete wiring kit on the way to re-do the chassis side. What I am looking to do is maintain the factory switch gear. At this time I am not using the M-button, but even if I were I would still have to figure out the same things in regard to making the factory switch gear work for the inputs for the M-unit, which is the whole point of this thread.

I agree with the small fuse panel. I actually have a small 4 position Mini fuse block sitting off to the side that I originally bought to remove the original glass fuses. It sounds to me like you are saying to maybe used a bussed fuse block though, which the current one I have is not.

I had the same idea for using the coil ground point for the front end. That is honestly where most of the grounds need to go anyway.
1975 GL1000 - Delkevic exhaust with stainless studs, Corbin Touring seat, Race Tech Gold Valve cartridge emulators, Progressive 11-1100 springs, Progressive 412HD rear shocks, Shinko 230 tires, Fork Brace, Trucklite 27270c headlight, X-Arc Signals (run, brake, turn), Hydraulic Clutch conversion, EBC Clutch discs, HD springs, and Barnett Steels + Plate B eliminated. BikeMaster DLFP-50N18L Lithium battery, Rick's Motorsports CBR600F4 Mosfet Regulator/Rectifier upgrade.
User avatar
Easter
True Blue Steel Biker
True Blue Steel Biker
Posts: 2999
Joined: Thu Sep 13, 2012 11:33 am
Location: South of Houston 100 miles

Re: M-unit wiring.

#4

Post by Easter »

Regarding the fuse panel, I was only saying you will need multiple outlets from the "accessory" terminal of the M-unit and a fuse panel is an easy way to connect. I did not use the factory switch gear so I can't offer help there. My strategy was to work one circuit at a time. I am using a digital tach/fuel gauge (which I have not been able to get the fuel gauge to work, but looks nice) and a mini mechanical speedo with dummy lights. I would like to add a water temp gauge and get the fuel gauge working. I played with it a bit taking the power for the 7 volt transformer from the accessory terminal but it did not appear compatible with the digital unit. Anyway, can't be much help with your plans beyond these suggestions.
Bikes at present:

83 XL 600r with a 2004 XR650L engine
And a slightly worse for the wear BMW GS adventure bike awaiting repair
83 GL in process :IDTS:
User avatar
Rednaxs60
Silver Member
Silver Member
Posts: 974
Joined: Mon Nov 30, 2015 11:14 pm
Location: Victoria, BC, Canada

Re: M-unit wiring.

#5

Post by Rednaxs60 »

Regarding the fuse panel, McGovern, over on the Classic forum, did some wiring changes that included relays and such. He found that the fuse block from an '85 LTD or '86 SE-i that has fuses and relays incorporated in the same fuse block was the answer. He rewired the fuse block to suit his application, used an air box from the same bikes to install it under the shelter. Has 7 relays and lots of fuses in one package.
LTD fuse block.jpg
LTD fuse block.jpg (69.13 KiB) Viewed 184 times
As for stacking connections on one post, the American Boating and Yachting Council (ABYC), default authority for the marine industry - I lived on a 40 footer for 5 years, recommends a maximum of 4 connections per stud as best practice. The more you stack, the more the possibility of having power issues due to corrosion between connectors. For a ground bus, I have found that marine components by Blue Sea to be excellent and a ground bus can probably be incorporated into your new wiring design. I have used this on my bike as a ground bus for new and old connections:
IMG_20160102_133710398.jpg
IMG_20160102_133710398.jpg (118.45 KiB) Viewed 184 times
Cheers
"When writing the Story of your life, don't let anyone else hold the pen."

Ernest

1985 GL1200 Limited Edition
2014 Can-Am Spyder RT LE
2021 Royal Enfield Himalayan
1995 GL1500 SE CDN Edition (sold)
2012 Suzuki DL1000 VStrom (sold)
Ontario 1985 GL1200 Limited Edition (sold)
2008 GL1800 (sold)
MegaDan
Titanium Member
Titanium Member
Posts: 373
Joined: Mon Jul 25, 2016 11:05 pm
Location: Omaha, NE

Re: M-unit wiring.

#6

Post by MegaDan »

Easter wrote:Regarding the fuse panel, I was only saying you will need multiple outlets from the "accessory" terminal of the M-unit and a fuse panel is an easy way to connect. I did not use the factory switch gear so I can't offer help there. My strategy was to work one circuit at a time. I am using a digital tach/fuel gauge (which I have not been able to get the fuel gauge to work, but looks nice) and a mini mechanical speedo with dummy lights. I would like to add a water temp gauge and get the fuel gauge working. I played with it a bit taking the power for the 7 volt transformer from the accessory terminal but it did not appear compatible with the digital unit. Anyway, can't be much help with your plans beyond these suggestions.
Well the M-unit Blue/Basic model is re-worked a little from the V2. It has 2 Aux spots with 3 outputs now instead of one, so it makes running additional outputs a little simpler. Aux 1 is a 20amp circuit with 2 output slots, and Aux 2 is a single 20amp output. It also has a separate Ignition output built in, and two starter relay circuits for 30 or 50 AMP use. It has some other features over the V2 as well, such as the capability to handle electronic speed sensors.

Thanks for the suggestions. Any information and advice is helpful.
1975 GL1000 - Delkevic exhaust with stainless studs, Corbin Touring seat, Race Tech Gold Valve cartridge emulators, Progressive 11-1100 springs, Progressive 412HD rear shocks, Shinko 230 tires, Fork Brace, Trucklite 27270c headlight, X-Arc Signals (run, brake, turn), Hydraulic Clutch conversion, EBC Clutch discs, HD springs, and Barnett Steels + Plate B eliminated. BikeMaster DLFP-50N18L Lithium battery, Rick's Motorsports CBR600F4 Mosfet Regulator/Rectifier upgrade.
MegaDan
Titanium Member
Titanium Member
Posts: 373
Joined: Mon Jul 25, 2016 11:05 pm
Location: Omaha, NE

Re: M-unit wiring.

#7

Post by MegaDan »

Rednaxs60 wrote:Regarding the fuse panel, McGovern, over on the Classic forum, did some wiring changes that included relays and such. He found that the fuse block from an '85 LTD or '86 SE-i that has fuses and relays incorporated in the same fuse block was the answer. He rewired the fuse block to suit his application, used an air box from the same bikes to install it under the shelter. Has 7 relays and lots of fuses in one package. LTD fuse block.jpg

As for stacking connections on one post, the American Boating and Yachting Council (ABYC), default authority for the marine industry - I lived on a 40 footer for 5 years, recommends a maximum of 4 connections per stud as best practice. The more you stack, the more the possibility of having power issues due to corrosion between connectors. For a ground bus, I have found that marine components by Blue Sea to be excellent and a ground bus can probably be incorporated into your new wiring design. I have used this on my bike as a ground bus for new and old connections: IMG_20160102_133710398.jpg

Cheers
Thanks for the suggestions. The M-unit is actually a solid state relay and circuit breaker setup, so it actually eliminates almost all fuses and relays currently in the system. I may need to add one or two relays with the EFI setup, but even that is an unknown quantity at this point. if I do need extra fuses, then it will only be a couple of them, so large fuse blocks would just take up a lot of space. I am still polishing up my wiring diagram, so I can't be too definitive at this point.

I agree with you on stacking grounds. My plan was to use a common ground wire much like the factory wiring, with a single 16ga. main wire going back to the ignition ground point, or the grounding point on the M-unit that is built in. 16ga. wire is actually more than enough to handle the amperage used by the LED head light, signals and running lights, and gauge lights on the bike. The other grounds are for momentary switching from the handlebars back to the M-unit, so their current draw is next to nothing. If I felt like a little insurance I could always move up to 14ga wire.

The bus bar suggestion does give me an alternative idea though.
1975 GL1000 - Delkevic exhaust with stainless studs, Corbin Touring seat, Race Tech Gold Valve cartridge emulators, Progressive 11-1100 springs, Progressive 412HD rear shocks, Shinko 230 tires, Fork Brace, Trucklite 27270c headlight, X-Arc Signals (run, brake, turn), Hydraulic Clutch conversion, EBC Clutch discs, HD springs, and Barnett Steels + Plate B eliminated. BikeMaster DLFP-50N18L Lithium battery, Rick's Motorsports CBR600F4 Mosfet Regulator/Rectifier upgrade.
User avatar
Rednaxs60
Silver Member
Silver Member
Posts: 974
Joined: Mon Nov 30, 2015 11:14 pm
Location: Victoria, BC, Canada

Re: M-unit wiring.

#8

Post by Rednaxs60 »

I put the ground bus bar under the seat on top of the rear fender.
Ground Bar Location.jpg
Ground Bar Location.jpg (154.28 KiB) Viewed 159 times
"When writing the Story of your life, don't let anyone else hold the pen."

Ernest

1985 GL1200 Limited Edition
2014 Can-Am Spyder RT LE
2021 Royal Enfield Himalayan
1995 GL1500 SE CDN Edition (sold)
2012 Suzuki DL1000 VStrom (sold)
Ontario 1985 GL1200 Limited Edition (sold)
2008 GL1800 (sold)
User avatar
sunnbobb
Facebook Admin
Facebook Admin
Posts: 21272
Joined: Thu Jan 10, 2008 4:09 pm
My Album: http://www.ngwclub.com/gallery/v/wingmans/sunnbobb/
Location: LaConner, WA

Re: M-unit wiring.

#9

Post by sunnbobb »

Fun aren't they?
I found the end of the internet

---- Bradshaw Bikes custom polishing for your wing. Visit us on facebook!

1978 Learning Experience
1980 County Road Hauler "Brain Damage"
1978 Cafe Custom Gl1000 "Vyper"
1977 Bulldog Inspired "Vaincre"
1981 Street Fighter GL1100 "No Quarter"
1983 Supercharged Street Drag "Anubis" (in worx)
1983 gl1100 mint restoration "Kristen"
1985 Aspencade..pondering.
MegaDan
Titanium Member
Titanium Member
Posts: 373
Joined: Mon Jul 25, 2016 11:05 pm
Location: Omaha, NE

Re: M-unit wiring.

#10

Post by MegaDan »

sunnbobb wrote:Fun aren't they?
A challenge for sure, but honestly the hardest part is simply working what the change to make work and what simply gets tossed.
1975 GL1000 - Delkevic exhaust with stainless studs, Corbin Touring seat, Race Tech Gold Valve cartridge emulators, Progressive 11-1100 springs, Progressive 412HD rear shocks, Shinko 230 tires, Fork Brace, Trucklite 27270c headlight, X-Arc Signals (run, brake, turn), Hydraulic Clutch conversion, EBC Clutch discs, HD springs, and Barnett Steels + Plate B eliminated. BikeMaster DLFP-50N18L Lithium battery, Rick's Motorsports CBR600F4 Mosfet Regulator/Rectifier upgrade.
Post Reply
  • Similar Topics
    Replies
    Views
    Last post

Return to “GoldWing Tech Discussions”