Stuck without a ride! Precedent lurches then rolls to a stop

[Sergio]

Maybe the safest way is just to take the voltage readings (New Version):

1) Set volt Meter to 200vDC and use alligator clips to measure the voltage on Controller B+ to B-.

Get the lowest voltage reading.

If the difference between the controller voltage reading and Your lowest pack voltage reading is more than 2v, the solenoid or cables are bad.


2) Test the MCOR resistance:

Set your meter to 20kΩ scale.
Disconnect the 3-pin MCOR connector
Measure the Resistance on the MCOR pins that correspond to Yellow and Purple wires.
Pedal Up to Pedal down should be from 1kΩ to 7kΩ (within 500Ω).

Measure the Resistance on the MCOR pins that correspond to Yellow and White/Black wires.
Pedal Up to Pedal down should be from 7kΩ to 1kΩ (within 500Ω).

Look for a smooth resistance change and no out of range (0L on most meters) readings.

[Camogolfcart]

Testing the controller; this feels like a stupid question but I assume I need to put the batteries back in and put everything back where it goes in order to test it per your instructions....correct?

[Sergio]

Yes, and you have to drive the cart to get the lowest voltage reading.

[Camogolfcart]

Okay I will start putting it back together and figure out a way to secure the tester ends to the controllers positive and negative....I will try and get back to you in the next 30 to 45 minutes I'm not sure how long it will take me to put everything back together.

[Camogolfcart]

Sergio, while I have the car taken apart and when ahead and disconnected everything in removed the solenoid altogether from the cart I also gave it a few taps because this is something I used to do with the solenoid in my old Jeep in college I'm not sure if it had anything to do with it but upon putting the solenoid back in The cart and putting all the batteries back in I just ran the cart around the neighborhood and stopped maybe 10 times and the cart seems to be running perfectly and picking up speed no problem!!!

[Sergio]

Did any of the connections looked bad?

Did the pre-charge resistor accross the big solenoid posts looked burnt?

That sometimes can indicate a solenoid that is going bad.

Hopefully it will keep running.

[Camogolfcart]

No real corrosion to speak of......while I was out I figured I'd run it through its paces before I turn it over to my folks for a week and pulling on to my street coming out of a stop the cart tried to bring itself to a heavy stop really quickly then went back to running normally. My wife said it felt almost like an axle or wheel fell off for a split second. I will run the test you mentioned on the controller and the Mcor to try to figure out the issue tomorrow. Is this forum something you check regularly? I feel bad asking you so many questions.....please know I really appreciate the help.

[Sergio]

I do check the forum often, but there are plenty of other folks here that regularly jump in when they can help.

At this point it is just speculation from my part since You don't have the voltage readings, but if the MCOR micro switch fails (same as pedal Up braking), the cart will use Regen Brake to slow down (main solenoid is still engaged).

If the Solenoid itself drops out, the Controller will use Dynamic Brake and it will be a lot harder (the same as roll-away braking after the cart has been stopped for over 10 seconds, main solenoid is not engaged).

Did the pre-charge resistor have any signs of overheating?

You mentioned back in post #9 something about a black wire connected to the solenoid for a flasher.

Did You disconnect it (since we don't know what circuit that wire is connected to)?

[greg-g]

A few things to check the two wires connected to the key switch and that circuit, wires connected to run tow switch