Troubleshooting Your Super 73 Z1 E-bike.

We on daily basis experience people ordering parts for their Ebike and then realize they misdiagnosed problem.  This can be a costly mistake.  So, in order to help you we created a simple guide to help diagnose the problem.  

First, you need to know that the most common failure on ebikes are the battery.  Many think that just because the "power" light comes on that the battery must be OK.  This is simply not the case.  In 99.9% of cases a dead/bad battery will still light up the power switch on seat.  This is because it only takes a couple volts/Milliamps to light the button.  Also, this seat switch is on a separate circuit in the battery than the Main Power (Output) and the Charger (Input) circuits.  The seat switch ONLY indicates the battery is "Turned On" and does not indicate the battery is actually functional. See Below:

To Test the battery you will need a Multimeter (Voltmeter).  First, turn on Power at seat.  Does Light come on?  If Yes, Turn on power at Throttle.  Does the Throttle Illuminate? If yes does it show full charge? If it Throttle does not illuminate, open seat to access battery.  Disconnect Battery from Controller only (Do not disconnect charger or switch connections).  Turning the seat switch to on so switch illuminates.  Use Voltmeter to see if there is voltage at controller connection.  Voltage should exceed 36V (if not charge battery).  If no voltage is detected battery is Bad.  If Voltage is detected battery should be at least "functional".  This does not mean the battery is "healthy", it simply means the battery should operate the bike.  If you are having short "runtime" issues this is indicator of a battery with low capacity and needs to be replaced.  Typically if battery is more than 3 years old you can almost expect the capacity to be going. Another possible indicator is you plug charger into bike and it never shows "Red" charging indicator. 

See Below:

Turn Seat switch to ON - Should Illuminate

Turn Throttle on.  Lights should Illuminate as shown.  If so, battery is most likely not the issue.  If no lights appear, battery could be bad.  

Access Battery and unplug from controller.  With seat switch "ON" take voltage reading.  If shows zero output - battery is bad.  If shows above 36V battery is almost certainly not issue.  Voltage indicates battery is at least "functional" and should power up the bike.

Replacement Battery can be purchased here:  https://batterygiantaz.com/products/36v-15ah-battery

The next most common failure is the "Splitter" cable.  This is the cable that connects to controller then splits the signal to Brakes and Throttle.  The location of the cable lends itself to internal wires breaking.  

The only way to test the cable is by checking continuity between pins.  You can do this with a continuity tester or using the continuity setting on multimeter.  Link to cable wiring pin out (diagram) is:

11 Pin Controller/Splitter: https://batterygiantaz.com/pages/z1-11-pin-splitter-cable-wiring

8 Pin Controller/Splitter:  https://batterygiantaz.com/pages/z1-8-pin-splitter-cable-diagram

Be sure to inspect Pins to make sure none are bent, broken. or damaged.

Replacement 11 Pin Splitter can be purchased here: https://batterygiantaz.com/products/super-73-z1-control-cable-1t3

Unfortunately, 8 pin slitter is currently not available.  Only option is for you to custom fabricate/repair using above diagram.  The other option is to order a new controller and 11 pin splitter.

The 3rd most common failure is the Throttle.  However, typically the throttle will only fail if it has sustained physical damage.  In other words - a crash, etc. Sometimes if bike is left in rain, water gets into throttle and will damage it as well.  Unfortunately, there really is no simple way to test the throttle.  Basically, if the throttle shows no damage - cracked, broken case or wires; it "probably" is not the issue.  This is not 100% Certain.  However, it is an inexpensive part and never hurts to have a spare.  Especially since Super 73 Discontinued the Z1 and all it's parts.  Currently, we are the ONLY source on Z1 replacement parts.  Simply because we have each made specifically for us.  

 Examples of damaged throttles.

Replacement Throttle can be purchased here:  https://batterygiantaz.com/products/super-73-z1-throttle-replacement

The next is the Controller.  Again, there is no simple way to test the controller without either a second bike or a little more specialized test equipment procedures.  So, if you have tested the battery, determined it is functional.  Made sure the the splitter cable is 100% functional (ALL connections have continuity).  Throttle has sustained no damage.  Then the next most likely issue would be the controller.  Controllers typically will only fail due to improper connections - hooked up incorrectly to bike or electrical issue such as over volting to increase speed or over load condition of some sort. This can be motor drawing too much current, too much weight on bike, poor terrain (sand, mud, extreme inclines, etc.)   So, if you need to replace controller, keep in mind something probably caused the failure and you may want to address it as to not burn up a new controller.  

Replacement Controller can be ordered here: https://batterygiantaz.com/products/super73-z1-controller

Note: Replacement controllers are 11 Pin Controllers.  If you have older 8 Pin Controller you will need to order 11 Pin Splitter Cable as well. 

Lastly, the least likely issue is the Motor.  While they do occasionally fail, in the years of working on these bikes, we have only seen one bike where the motor was the issue.  Unfortunately, this is not a part we have available. If this is the case, or the above tests have yielded no results, you will need to take bike into a professional service center to have repaired. 

Please Note: Be sure you need the parts you are ordering.  Due to the ease of damage to controllers not hooked up correctly and ability to misdiagnose problems they are not returnable.  Rest assured all controllers are tested prior to shipping and are new and working when shipped.  

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 The very first thing you should do if Bike powers up but does not run:  In other words - Seat switch illuminates, Throttle lights illuminate, yet bike does not run:  First, Unplug both Brake plugs.  In some cases the brake switch is defective, or the wires may shorted.  In which case the bike thinks the Brakes are engaged and will not run.  If you unplug brakes and bike still does not run proceed to below checklist.  If this solves problem replace brake or faulty cable.  Or, use unplugged until you can repair. 

Z1 is not working:

  • Turn Power on at seat. Does switch Illuminate?
    1. Yes: Move on to step 2
    2. No: Either you have bad Battery, Bad switch, or bad connection between switch and battery.
  • Turn on power at Throttle. Does Throttle Charge lights illuminate?
    1. Yes: Odds are Battery is functional. Make sure battery is fully charged. Check, Splitter harness, throttle, Controller, and all connections.
    2. No: You either have bad battery. Bad Splitter cable, Bad Throttle. Move on to step 3. If you plug in charger and no charge (Red) light comes on, most likely bad battery. 
  • Open seat to access Battery/Controller. Unplug battery from controller.  Leave switch and charge connectors in tact.  Turn on Switch at seat and make sure switch is illuminated.  With volt meter check voltage on battery.  Is Voltage present?
    1. Battery is most likely not the issue.  If Voltage is below 36V – charge Battery and move on to next step. 
    2. If switch is on and illuminating and you have no voltage battery is defective.
  • Un-plug 1T3 Splitter cable from Controller/Throttle/Brakes. Using appropriate harness wiring diagram from this site, check continuity between each pin. Does every pin on diagram show continuity?
    1. Harness is good reconnect harness. Move on to step 5
    2. Harness is defective. Repair or replace.
  • Inspect throttle for physical damage. Turn on power at throttle. Does Throttle light up showing battery level?
    1. If throttle lights up when turned on, “odds” are the throttle is functional.  This is not a guarantee.  If shows physical damage replace regardless to prevent any further damage. Move on to step 6
    2. If Battery has tested functional, Splitter is testing good, and throttle does not light up,,, Replace Throttle.
  • Controller – this is most complicated to troubleshoot. It is mostly process of elimination.  If battery, splitter, throttle, and all connections are good, then “most likely” a controller issue.  One thing to keep in mind is that even if controller is bad – most likely the throttle light (battery gauge) will illuminate.  Basically, usually bike will power up just will not necessarily go.  This is not ALWAYS the case, but in MOST cases this is true.  The reason for this is that the typical failure on controller is not on primary side of circuit.  In other words, power goes from battery, into controller, to the throttle power switch.  Therefore, even a defective controller typically will light the throttle indicators.

Check ALL connections starting at throttle, Brakes, Splitter to controller.  Battery to Controller, Controller to Motor.