Topic: M-unit dying - Possible winter warning

[Rick4004]

I bought an M-unit in 2015, but only got the bike on the road in 2019. It spent the winter of 2019/2020 in a heated garage. Everything worked good in 2020. It spent the winter of 2020/21 in an unheated garage, but we had a pretty mild winter. All was good in 2021, but the winter of 2021/22 was extra cold here in Winnipeg. There were many days/nights where the temps were colder than -30C, so I'm sure then temps in the garage were near -30C.

So, here comes spring of 2022, I install the battery, and notice that the right side running lights don't work. The wiring checks out OK, so I just live with it. Over the next week I notice the running lights work, then don't work. Then the right signal stops working intermittently. Next thing I experience is that the bike is completely dead when I press the start button if the temps are any cooler than about +15C. If I hit the M-unit with a hair dryer, to warm it up, then the bike starts.
I begin to worry that the bike is going to leave me stranded, so I pony up for a new M-unit. Of course they have completely changed the form factor of the new version, so I had to change it's mounting location, and extend the wires to the new location. Not to mention they don't make the basic unit anymore so they force you to pay an extra $150.00 for the stupid blutooth version, that is just a total waste of money.

Since the wires needed to be extended,  I took the opportunity to build a sub harness with Deutch connectors so that I can unplug the M-unit and bring it in the house in the winter.

In all, the original unit lasted 3 seasons, and about 15,000KM. I can't be sure that it was the extreme cold that did the original in, but I don't want to fork out another $600CDN for another one if I don't have to.

[calj737]

You could very easily confirm your suspicions by removing the wires from the mUnit and check them. Given the temps you described, it is entirely possible corrosion has occurred inside the screw port and you are encountering intermittent ground signals to switch the power.

The unit is solid state, and last I checked it’s rated to operate in those temps, so I would have looked beyond the unit itself. I have 2 units going on 8 years (granted I don’t live in Winnipeg) and have not had an issue with them. You’re the first I’ve heard having temp-related failures.

I also prefer the prior model form factor and mounting. I have no use for the BT features on the newer unit. Progress I guess…

[Rick4004]

I found that I could get the right hand running light to work by pressing on the output screw head, so it seemed like an internal mechanical issue to me.

I happened upon the heat related issue because I pulled the unit from the bike to bench test it and video document the problems. I brought it in the house, and by the time I had a bench power supply set up it had been in the house for 3-4 hours. When I tested it, everything worked fine, and I thought maybe the unit had "reset" itself once the power had been fully disconnected.

I installed the unit back in the bike, and everything worked properly. Problem solved,,,until the next morning when I tried to start the bike (temps about 12C). That's when it struck me that the only difference between one day and the next was the temperature. I heated the unit up with a hair dryer, and it worked again.

The temp specs that I found stated -20C, and it was certainly colder than that in the garage last winter.
My local Motogadget dealer said this was the second of the 1st gen units that he's seen with similar problems. I'll probably send it back to the factory for repair, but I didn't want to miss half the riding season waiting for it.