Yamaha ydre wont't run

[ojo]

Hi all,

got a new project, 2007 yamaha ydre, that won't run. cart came without charger, so first loaded batteries separately, pack voltage ~50v. On a first check, i detected the following symthoms:
When switch to on, no click from solenoid
Switching run/tow, no cllck from solenoid
Pushing the cart forth/back, no motorbrake, no click
Only when pushing the gas pedal, it clicks, and when pedal is off, clicks again.

I'm not new to carts, but new to Yamaha and the ydre was so cheap, that i couldn't walk away

Any suggestions, from where to start?
Rgds ojo

[Volt_Ampere]

There are two weak points on the YDRE: Motor and Controller. I would first suspect that the motor is shot - brushes worn down to nothing. (if it's the stock Hitachi motor) Does the reverse buzzer work when you put it in reverse mode?
Measure the resistance between the two armature posts. Should be very low.

[ojo]

Yes, it's the Hitachi motor, and yes, the buzzer comes in reverse. I've just messured at the solenoid in tow position, from battery 49.9v and other post to controller 0.3v?? Resistance between big post's on Motor 0.8ohm.
Thank you!

[camaroluvz28]

Try this...Tap on the end of the motor cap with a hammer while in tow and then go back to run...try the cart again. Sometimes if the motor brushes are stuck this will get cart moving again...that's not a fix, its just an easy way to diagnose bad motor brushes that often works.

[Volt_Ampere]

If you have help, you could measure the voltage across the motor armature terminals while someone presses the pedal in fwd. Either lift the back wheels off the ground or prepare for the cart possibly moving forward. If you get voltage there and the cart doesn't move, then the motor is the problem. If the solenoid doesn't click, then you need to chase the solenoid circuit. The controller controls the solenoid but the run/tow switch and ignition switch also have to be closed to get the solenoid to engage. ALso, there is a 3 amp fuse in that circuit located in the driver's side of the battery compartment. It's not that easy to find the first time. (been there!)

[ojo]

Got a new charger today, so i can charge the batteries completely first and will do the other tests tomorrow. Also trying to find these 3 amp fuse and my 🔨
Thank you Guys, appreciate it.

[cgtech]

Originally Posted by ojo

Got a new charger today, so i can charge the batteries completely first and will do the other tests tomorrow. Also trying to find these 3 amp fuse and my 🔨
Thank you Guys, appreciate it.

If you get reverse buzzer & solenoid click, 3a fuse is good. And I think you have a failing motor.

When the Moric controller fails its usually 100% gone, no solenoid click, no reverse buzzer (both are actuated by the controller).

[ojo]

Yes, you all're right... batteries completely loaded, tried with the hammer (not too hard), but won't run. Found the fuse, as cgtech says, it's OK. Then with lifted rear tyres and a friend of mine at the accelerator, i've checked at the motor and got voltage at green wire, motor still dosn't move! Everything points to stuck/worn brushes... will order them today. Thank you all so far

[Volt_Ampere]

Please explain where you got motor voltage! You want to measure across the A1 and A2 terminals. Not the F1 F2. You can measure there too but the high current that goes through the brushes goes into the A1, A2 terminals.

[ojo]

Was something wrong? I took negative from batt. pack, on A1/A2 = 50.7v, on F1 = 0v, on F2 = 30+ v when accelerating, down to 0v when decellerating.