Cart won't go!

[cpacetti]

Based on the sticky I have identified my cart as a Sepex / PDS type. Put it on jack stangs and did the diagnostic check - that seems OK and I can hear the solenoid clicking to engage. If you spin the tires as you hit the accelerator the motor kicks on but not too strong. Nothing seems to be heating up, just barely turns the tires.

I bought this cart about 6 years ago - it's lifted with 22 inch tires and as far as I can tell it's totally stock other than the lift and tires. Batteries are 1 year old and testing good. I have used this cart off road and had it shut down and then go again after a few minutes, seemed like the motor was overheating. Have I cooked the motor?

Thanks for any help,

Chuck P

[Bowslayer]

The controller is most likely shot. Stock PDS controllers don't like over sized tires.

[scottyb]

If you can verify the battery pack voltage is not dropping drastically under load & the controller output is full voltage then the motor would be very suspect.

[JohnnieB]

Yes, it could be a motor problem, but the problem could also be the batteries, the controller, the high current cables, the solenoid contacts or the ITS (Throttle). Plus a few other things.

What is the battery pack voltage about 12 hrs after the charger turns off?
Should be 38.2V, Each battery should be 6.37V and all six should be withing 0.1V of each other.

Connect the negative test lead of your DVM to the B- terminal on controller.
Connect the Positive lead to the M- terminal.
With Run/Tow in RUN, Key ON, F/R in F and pedal pushed until solenoid first clicks, you should read FULL battery pack voltage.

If you don't get FULL battery pack voltage, there is a problem in the high current loop.

If you do have full battery pack voltage, slowly press throttle pedal to floor. (Wheels off ground)
Voltage should smoothly decrease to zero.
IF not, we will have to check out throttle input and some other things.

Tell us what you find and we will proceed from there.

[cpacetti]

OK, thanks for the input - I'll do some more checking and report back.

[cpacetti]

Where is M-??

[JohnnieB]

Originally Posted by cpacetti

Where is M-??

Oooooops! M- is called A1 on PDS carts.

[cpacetti]

What is the battery pack voltage about 12 hrs after the charger turns off?
Should be 38.2V, Each battery should be 6.37V and all six should be withing 0.1V of each other. The battery pack voltage is 37.2, batteries are equal.

Connect the negative test lead of your DVM to the B- terminal on controller.
Connect the Positive lead to the M- terminal.
With Run/Tow in RUN, Key ON, F/R in F and pedal pushed until solenoid first clicks, you should read FULL battery pack voltage. Reads 33.7 before pushing pedal, drops to 2.8 to 3 once solenoid clicks, then decreases to zero as pedal is pushed to floor.

If you don't get FULL battery pack voltage, there is a problem in the high current loop.

If you do have full battery pack voltage, slowly press throttle pedal to floor. (Wheels off ground)
Voltage should smoothly decrease to zero.

Check out this photo - this is the + battery cable. It has gotten so hot that it had melted into the controller. Whoops, I guess I can't add photos yet.

[JohnnieB]

Originally Posted by cpacetti

1. Should be 38.2V, Each battery should be 6.37V and all six should be withing 0.1V of each other. The battery pack voltage is 37.2, batteries are equal.

2. With Run/Tow in RUN, Key ON, F/R in F and pedal pushed until solenoid first clicks, you should read FULL battery pack voltage. Reads 33.7 before pushing pedal, drops to 2.8 to 3 once solenoid clicks, then decreases to zero as pedal is pushed to floor.

3. Check out this photo - this is the + battery cable. It has gotten so hot that it had melted into the controller. Whoops, I guess I can't add photos yet.

1. The batteries are only about 70% charged, so the plates are sulfating as we speak.
Charge them and keep them charged as fully as possible. (IE: Charge after each use.)

2. The 33.7V before the solenoid clicked is due to the Precharge resistor across the solenoid's main contacts.
Only about 3V when solenoid clicks tells me you've got some very high resistance in the high current cables or contacts, or bad batteries.

3. Sounds like you found a problem.
This would be a good time to replace all 10 of the high current cables, the rest of them probably aren't in much better shape the the one that's getting hot.

These are the ones (2Ga) I use. http://www.cartsunlimited.net/Batter..._Upgrades.html

[cpacetti]

Thanks Johnnieb - it looks like I would need kit #11. You think I should get the cables, install them and then go from there? Is there further diagnostic work I need to do before ordering the cables? Sorry to ask so many questions, but this forum and you are a great resource!

Chuck P