Heavy Spark on new batteries.. Trying to troubleshoot

[Mooncarter]

First check and make sure you don't have some nekked cables touching each other or the frame.

[dazed-n-confused]

I appreciate the direction, but need some clarity. So I have a gator clip on the the disconnected large black lead which I will connect to my negative on the multi-meter. I am a bit fuzzy on the positive side. Am I disconnecting the red large wire and isolating the batteries from the controller, obc etc from the batteries and ohm out the smaller wires, or am I needing to keep the red large positive connected and then ohm out the disconnected smaller wires.

Sorry for the confusion and thanks for your patience.

[WalterM6]

Negative connected to the black wire. Connect red probe one at a time to the large red wire and then the small wires. You should read a short(zero resistance) or low resistance on one of the wires.

[Fairtax4me]

Checking resistance tells us next to nothing when dealing with cables this large.
Can you post some pics of the wiring on your motor, controller, and solenoid?
Something is not connected correctly or there is an obvious problem (missing or burned insulation) on the main cables that go to the controller or motor.

[WalterM6]

Checking resistance tells us next to nothing when dealing with cables this large.

Care to explain that?

[Catchinrays2]

OH NO!!!! I am having the exact same problem on my cart and I was hoping to see the solution....but it just ends. If ANYBODY has any idea what the fix to this problem is or was, please post the solution here....I'm about to go crazy here trying to figure it out: I have everything hooked up correctly - Curtis 1266-5201, Advanced ZQS48-3.0-T motor. But each time I go to attach the last wire (Negative lead from controller to batteries, I get a spark that's powerful enough to weld). Thanks for any help.

[HarryT]

Did you check all the batteries to make sure one or more are not charged in reverse.
Harry

[Catchinrays2]

Originally Posted by HarryT

Did you check all the batteries to make sure one or more are not charged in reverse.
Harry

Yes, I get 50 volts at the + and the - battery terminals before going to their respective attaching points (well, I tried to hook up the B- on the Controller to the negative battery post - and that's when I started trying to weld). Does any of this problem have to do with attaching the M- on the controller to the A2 or the A1 on the motor? One diagram I found has M1 going to A1, the other has M1 going to A2. Does it matter? Thanks.

[ls1chris]

have you probed the solenoid for continuity on the large lugs? stated it has been replaced with a heavy duty, is it a N/O or N/C? sometimes they send you a wrong one. why was the cart parked in the first place? have you checked the motor to see if it is grounding to the case? ( lug leads to case with a meter) i guess you could disconnect everything ( lead to solenoid, controller, motor) and reattach one by one and test for lightning on the batteries again one by one to find the broken part.
and this " Does any of this problem have to do with attaching the M- on the controller to the A2 or the A1 on the motor? One diagram I found has M1 going to A1, the other has M1 going to A2. Does it matter?" was it previously working in this state? or did someone tinker on this recently?

[Catchinrays2]

have you probed the solenoid for continuity on the large lugs?

I have checked the solenoid on the work bench - seems to work fine with a 48 volt input to the small probes (should they need 48 volts at the small probes to activate it?) and I can hear it clicking and turning on my "Test" light just fine - but the odd thing is that when everything is hooked up (other than the the big negative wire to the battery) it already is registering continuity between the big posts on the solenoid, so that really confuses me.

stated it has been replaced with a heavy duty, is it a N/O or N/C? sometimes they send you a wrong one. why was the cart parked in the first place?

I don't know what a N/O or N/C is, so I don't know if I have the correct one or not.

have you checked the motor to see if it is grounding to the case? ( lug leads to case with a meter)

I have not done that, but I have checked the motor directly to batteries and it seems to work just fine.

(i guess you could disconnect everything ( lead to solenoid, controller, motor) and reattach one by one and test for lightning on the batteries again one by one to find the broken part.

If have disconnected everything, and reinstalled everything, but not one by one - I really wouldn't know what to test for as I attach each component.

One diagram I found has M1 going to A1, the other has M1 going to A2. Does it matter?" was it previously working in this state? or did someone tinker on this recently?

This is a project cart and is being passed from one person to the next, and so, far as I'm the next owner in line, have not figured out what the problem is. I would imagine its something very easy because of the massive weld spark i'm getting when trying to attach the last - battery lead to the battery, and would guess it hassomething to do with the solenoid, becasue it just doesn't seem to act right once in the cart, but since they're simple switches, I just have no idea why I'm getting continuity between the big posts once I install it.

I appreciate the help.