MP not running- all throttle lights are on?!

[magicaffair]

Morning all, I've been enjoying my MP2 for a while now, but on the way back from the shops the other night, the bike stuttered and died?! Throttle lights disappeared then came on again with just the red showing. (battery had a full charge) I've now got all lights up on throttle, but noting at all from the motor. All connections seem okay too (moving the main battery cable at the terminal caused intermittent lights, but i've plugged it firmly and they're on now. Still no power at all?)

 The wheel did grunt a couple of times immediately after it died... but now i'm getting nothing... just three lights, and no movement. Any ideas? I'm thinking a loose connection... but all seems okay. (i do have an external GM controller but all looks okay there too) 

[Bikemad]

Poor battery connector contacts or switch contacts can sometimes prevent battery power reaching the controller, but as you appear to have all three LEDs lit up, it would seem that the battery voltage is reaching the controller under a no load situation, but this may change when load is applied, if one of the contacts is still poor.

As you have the external controller it will be a lot easier to carry out some simple checks with a voltmeter to see if anything obvious can be found.

Set the meter on a DC voltage range suitable for your maximum battery voltage and start by checking the battery voltage at the controller between the B+ and B- terminals.
Leave the black meter probe connected to the B- terminal and then test the following contacts with the red probe:

• G Should show battery voltage
• Z/0V Should read ~0V
• B Should read high with the brakes released and ~0V when the brakes are activated
• T1/5V Should read ~5V
• T2 Should vary between ~0.8V and ~4.5V when throttle is activated (make sure the wheel is clear of the ground just in case it starts to spin)
• H+/5V Should read ~5V
• H-/0V Should read ~0V
• Ha Should alternate between 0 and ~5V when the wheel is moved very slowly by hand
• Hb Should alternate between 0 and ~5V when the wheel is moved very slowly by hand
• Hc Should alternate between 0 and ~5V when the wheel is moved very slowly by hand

If all of the above checks produce the expected readings, you will need to check the phase wires to rule out the possibility of a break or poor connection on either the phase wires and/or the motor windings:

• Turn off the power and disconnect the three thick Yellow, Green and Blue wires from the controller.
• Turn the wheel by hand and make sure it turns smoothly.
• Use a bare metal paper clip (not a plastic coated one) to connect the Yellow and Green wires together and check to see that the wheel is now stiff and notchy to turn by hand.
• Remove the paper clip and reconnect it between the Yellow and Blue wires and see if the wheel is also stiff and notchy to turn by hand.
• Remove the paper clip and reconnect it between the Green and Blue wires and see if the wheel is also stiff and notchy to turn by hand.
• Reconnect the three phase wires to the controller and check that the wheel now turns smoothly again by hand.

If the phase wire checks also produce the expected results, I suspect that the controller might have been damaged if a battery connection had become intermittent during use, especially if you had been braking at speed just before the failure occurred.

Please let us know what you find with the tests.

Alan
 

[Morgen 3Eman]

Hi Magic..

Alan is an absolute genius for troubleshooting, but he forgot one thing to check.  If the brake switch is made, the motor won't run.  Check your brake levers aren't ajar.

TTFN,
Dennis

[Quiro]

You can re check as well the cable signal. I have had a problem like that and I was worry that something broke down but after I twisted a bit the signal cable was working again with out problem.

Quiro

[Bikemad]

Alan is an absolute genius for troubleshooting, but he forgot one thing to check.  If the brake switch is made, the motor won't run.  Check your brake levers aren't ajar.

Set the meter on a DC voltage range suitable for your maximum battery voltage and start by checking the battery voltage at the controller between the B+ and B- terminals.
Leave the black meter probe connected to the B- terminal and then test the following contacts with the red probe:

• G Should show battery voltage
• Z/0V Should read ~0V
• B Should read high with the brakes released and ~0V when the brakes are activated
• T1/5V Should read ~5V
• T2 Should vary between ~0.8V and ~4.5V when throttle is activated (make sure the wheel is clear of the ground just in case it starts to spin)
• H+/5V Should read ~5V
• H-/0V Should read ~0V
• Ha Should vary between 0 and ~5V when the wheel is moved very slowly by hand
• Hb Should vary between 0 and ~5V when the wheel is moved very slowly by hand
• Hc Should vary between 0 and ~5V when the wheel is moved very slowly by hand

Dennis, I tried to ensure the tests that I suggested would cover all of the possible problem areas that I could envisage, without having to provide extensive details explaining why each check has to be performed.

If the result of any of the tests is not as expected, we can then focus our attention on that particular problem area.

A stuck lever (or faulty brake switch/shorted brake wires etc.) would have been highlighted during the third check that I suggested, as the voltmeter would have been continually reading ~0V, even with the brakes released.
By checking the reading with the brakes applied and released, it helps to identify where the problem could be.
If the reading remained high with the brakes activated, this could simply signify a fault with either the brake switches or their wiring, or more likely a break (or poor connection) somewhere in the main ground connection between the controls and the controller, which would definitely prevent the motor from running. Test no 5 could also help to confirm the same fault if the throttle signal remained high when the throttle was released.

Certain tests that I sometimes suggest, may appear to be unorthodox, unrelated, or perceived by others as totally unnecessary, but after decades of troubleshooting and problem solving (both mechanical and electrical) I have learnt to keep a very open mind, and never to rule out the unexpected. 
So there is usually a valid (and logical) reason for the questions I ask, and the tests that I suggest.

Sometimes I just wish I could remember what that reason was.


Alan
 

[magicaffair]

Thanks again everyone for quick responses. Thanks Alan for your surefire advice. I checked all connections yesterday and everything seems ok. I even took the throttle lever apart to check innards... all looked ok (what I presumed was was a hall sensor inside, but this seemed okay too)

Went up the road with same problem persisting, after ten minutes or so pedalling and continually trying throttle, the motor grunted a few times.. then came back to life!!   

The throttle is not working this morning, however, so i'm thinking there must be a poor connection somewhere.  My voltmeter is with a friend so can't test voltages at mo, so im checking and rechecking all cabling now!

[Morgen 3Eman]

As I said, Alan is a genius.

I'll shut up now.

Dennis

[magicaffair]

Hi all, thanks to Alan, as usual :-), I checked the phase wiring, and sure enough the Blue wire had fault somewhere... I traced it back to the motor casing where it was chaffed on the sharp edge. I took the pie apart and rewired it (painstakingly as wires were now too short!) I wired just the phase wires (Blue Green and just the three wires representing the yellow phase)  without the hall sensors, and put her back together. She's now running great in true sensorless mode... just need to be moving and the power kicks in ...thanks for the comments. Happy trails everyone