Have Magic Pie 5 and need help in figuring out why I have lost like 75% power

[Rambler]

Hi,

I am new to the ebike world and have already built 2 bikes. I am in need of some help from you awesome Magic Pie V5 experts.

I have a Magic Pie 5 and need help in figuring out why I have lost like 75% of my power.

I have a 48v 11amp Luna Shark Battery. Which is testing (volt meter) at 52 to 54 volts output. So I'm pretty sure that its not a battery issue.

I bought a new throttle thinking that that was the issue. Both have a button on the bottom. The old one use to turn the lights (on the throttle) on and off when I pushed it. Then about a day before it lost power the button STOPPED turning the display lights on/off. ALSO the throttle does NOT engage until about 70% "turn". Thus the reason I bought a new one. The NEW ONE is acting EXACTLY as the old one did. (lights, 70% turn before power).

I have to the best of my abilities tested and checked the power cables. All seem to be fine and I have unplugged and replugged all of them as needed. 

Everything was working fine until I unplugged the throttle replugged in back in (after I parked it). Any help would be awesome and appreciated.

Thank you

Rambler

 

[Bikemad]

Hi andto the forum.

I'm not sure whether you have a wiring fault or a problem with the +5V output from the controller.
Have you checked the pins on the throttle connector to make sure none of them have been bent or damaged?

The switch on the throttle is supposed to switch the battery voltage to the red lighting wire on the front harness to power a battery voltage LED headlight, not to turn the throttle mounted battery gauge LEDs on and off.

If the motor is down on power, and the throttle does not work for the first 70% of movement, it sounds like the voltage on the +5V supply is too low.
Check out this post for more information.

If you unplugged (or plugged in) the throttle connector while the battery was turned on, it may be possible that the +5V supply could have been momentarily supplied with full battery voltage (via the battery gauge and throttle Hall sensor) if the Battery +ve and +5V pins both made contact before the Ground pin, which could happen if the plug was removed/inserted at a slight angle instead of being perfectly in line. 

I suggest that you check the voltage between the unused thin red +5V and black ground wires on the motor harness (see diagram below) and check that you have around 4.25V across these two wires with the battery turned on.
If you have less than 3V instead of 4.25V, this would explain your problem.



If the +5V output from the controller has been damaged (output is less than 4V), you will either have to replace the controller, or rig up an alternative +5V supply to power the throttle Hall sensor.

Be very careful not to touch the wires together while testing, and also make sure that the four unused wires on the motor harness (and the four unused horn/lighting wires on the front harness) are all safely insulated.

Alan
 

[Rambler]

Hi Alan,

"If you unplugged (or plugged in) the throttle connector while the battery was turned on, it may be possible that the +5V supply could have been momentarily supplied with full battery voltage (via the battery gauge and throttle Hall sensor) if the Battery +ve and +5V pins both made contact before the Ground pin, which could happen if the plug was removed/inserted at a slight angle instead of being perfectly in line.  "

What happens or more importantly IF the above happened...how do you recommend I fix that?


"I suggest that you check the voltage between the unused thin red +5V and black ground wires on the motor harness (see diagram below) and check that you have around 4.25V across these two wires with the battery turned on.
If you have less than 3V instead of 4.25V, this would explain your problem."

The wire that is NOT being used that goes into the wheel with the Red, Black, Blue and Yellow wire?

Thank you for your help Alan. Means a lot to a noob! 

[Rambler]

UPDATE:

I checked the plugs and checked power as indicated. (I think).

After checking everything...now I have lost ALL power to the hub. As in ZERO movement with Throttle. Yet all lights to the throttle works.

I am hoping that this is one of those "for sure" signs that "x" is wrong.

The power seem to test at 4.98v or so everywhere I checked. Including that stray wire by the hub that I was not using.

Is it safe to assume that "x" (what is wrong) is the controller?

My wiring kit has NOT gotten here yet from Luna (tracking says it was shipped Tuesday nite). I guess I'm stuck until I get it since I cannot rule out the wiring harness.

I did read that other string that you attached, looks like the same issue...maybe.

Any help would be awesome.

Thank you

[Bikemad]

If you have 4.98V between the red and black wires that the arrow is pointing to;



then the controller's +5V supply must still be working OK.

It is unlikely that both throttles are faulty, so I would say that it is either a fault somewhere between the throttle signal wire between the throttle and the controller, or the controller itself.

If the new wiring kit doesn't cure the problem (when it arrives) it is likely to be the controller that will need to be replaced. 

If you unplugged (or plugged in) the throttle connector while the battery was turned on, it may be possible that the +5V supply could have been momentarily supplied with full battery voltage (via the battery gauge and throttle Hall sensor) if the Battery +ve and +5V pins both made contact before the Ground pin, which could happen if the plug was removed/inserted at a slight angle instead of being perfectly in line. 

Perhaps high battery voltage has damaged a component on the throttle signal circuit within the controller instead of the voltage regulator for the +5V supply. 

Alan
 

[Rambler]

Thank you Alan.

I don't know if you work for Golden Motors (GM)...but IF you don't...I hope they are giving lots and lots of goodies cuz you are amazing!

I have gotten more info from YOU then my call to GM.

I won't bore you with details, lets just say I am GRATEFUL for YOUR support sir!

Thanks again!

[Rambler]

Alan,

Last (I hope) question sir.

Does this : https://lunacycle.com/parts/hub-motor-parts/golden-pie-twist-throttle/

Work with Magic Pie V5? I have been told NO and YES. May I ask YOUR opinion sir?

My harness came in and it's still INOP, I think the NEW throttle I bought was INOP. It's STOPPED working and my OLD one still work, even though it's still just at about 10% Power. It still works though.

IF you say YES that "twist" will work, I'm going to Luna on Monday to get it.

Thank you Alan

Rambler

[Bikemad]

That throttle should be fine.

The description states that it is suitable for versions 4 and 5, so that includes your Magic Pie V5.
The same throttle is also used for the Vector Smart Pies and the Magic Pie Edge.

The earlier Magic Pies had male pins on the throttle connector plug, whereas the later ones have the pins on the control harness connector and female sockets on the throttle plug (as shown in one of the pictures of the linked throttle).

Do you still have 4.98V between the red and black wires with the old throttle plugged in?

If so, does the 4.98V reading change when you press the red button on the throttle?

Alan
 

[Rambler]

Update:

Issue was Controller! Bought one on the spot at Luna. Jack (from Luna) gave me tools to install it. I did, it worked 100%!

Also: Twist throttle Luna sells worked 100%! So I traded the thumb one I bought for twist, since the one I originally had worked 100%.

Since I was there, and Luna is so AWESOME. I decided to have them build my wheels for me.

https://lunacycle.com/weinmann-dhl80-26x4-36h-fat-bike-rim/

Yeah, double walled and 50.00! So in about a week or less, I'll have my Fat Tire MP5 on my bike! Can you tell I'm excited?

Alan, Once again thank you man! Truly appreciate your help sir!

Rambler