Author Topic: Motogadget M-unit Starter output not working  (Read 1575 times)

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Offline blackwell05

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Motogadget M-unit Starter output not working
« on: June 14, 2018, 10:21:35 AM »
I have had my motogadget m-unit installed for a year now, and after having it sit this winter. I go to start my bike and nothing. So I charge the battery, still nothing. Check the solenoid, works fine. All things seem to point to the M-unit not giving an output. The m-unit indicator light is saying it should be giving an output but nothing. The right turn signal output isn't working either. All other outputs work fine. I've heard these things are basically bullet proof, yet here I am. Any help would be appreciated.

Offline calj737

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Re: Motogadget M-unit Starter output not working
« Reply #1 on: June 14, 2018, 02:05:15 PM »
So if you push the START button on your bike, what lights show up on the M-Unit?

Same for the TURN R button? Have you confirmed that neither front or rear TURN are lighting up? What about the instrument cluster? Does the TURN bulb show?
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Offline piefairy

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Re: Motogadget M-unit Starter output not working
« Reply #2 on: June 18, 2018, 05:12:58 PM »
Just to state the obvious... I have tried to start up the bike when not in neutral on more than one occasion. The indicator light on the M-unit will show, but since there is no ground to the motor, you get nothing. Make sure all your starter safety switches are good and that you have the correct neutral/clutch/kickstand position.

Offline blackwell05

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Re: Motogadget M-unit Starter output not working
« Reply #3 on: May 23, 2021, 07:53:33 PM »
So if you push the START button on your bike, what lights show up on the M-Unit?

Same for the TURN R button? Have you confirmed that neither front or rear TURN are lighting up? What about the instrument cluster? Does the TURN bulb show?

The output light still shows up but it doesn’t have any actual output. It hasn’t worked since I posted his three years ago. I just bypassed the munit for my starter button but I want it to work properly

Offline Bodi

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Re: Motogadget M-unit Starter output not working
« Reply #4 on: May 24, 2021, 06:08:25 AM »
I've only fiddled with one, tracking a similar problem. That was a bad ground on the light. But although I didn't look into the controller closely I think many outputs - maybe all - are solid state devices not relays. The troubleshooting guides say to use filament test lamps not LEDs... pretty sure sign of a transistor output.
These transistors - whether junction, FET, MOSFET, whatever - are susceptible to several dangers that relays don't care about.
The little indicators can be fed from before the output device, be lit without the actual output being live. I haven't found any circiit details for the m.unit. If the idiot light is on but you have no voltage on the output... something has failed in there. Solenoid control is a problem for transistors because of the inductive kickback voltage. It is easy to protect against in theory but the protection devices can also fail. A relay will get damaged contacts from kickback arcing but it takes a lot of use and relays tend to be cheap and replaceable. One voltage spike can kill a transistor instantly, often difficult to replace (or actually be designed to be impossible to replace... hello Apple...).

I appreciate the many benefits of the m.unit but I'm a cantakerous old bastard and strongly prefer actual switches. I have a newish car with everthing CANbus and 10 computers yakking at each other but fondly recall my 70s first car that I could actually fix with simple tools. I have no desire to take my old bikes, remove their simple switchgear, and add a black box electronic geegaw controlling everything.