Bad PWM cables?

[eneubec1]

I'm looking for a little guidance from those experienced with multiple seasons of FRC electronics.

We are a team entering our 3rd year and my electrical team this year handed me 6 PWM cables and told me "these are all bad".
I have seen pwm cables last year that were causing some intermittent issues on a motor controller, but I thought that was an anomaly. I'm a bit shocked that we would have 6 PWM cables that are bad when the oldest ones we have are 3 yrs old. There really isn't much too them.

Is there some "crimping maintenance" or something else to do with these cables to address what seems to be an intermittent crimp on these cables?

Thanks in advance.

[Mr. Lim]

What kind of speed controllers are you plugging them in to? Victors are sometimes difficult to plug cables in to, as if you don't put them in perfectly straight, the pins miss the connector inside. This is often mistaken for a "bad wire"

[Jon Stratis]

The easiest way to tell is with an ohm meter - check for continuity of each wire from one connector to the next, and you'll know if the wire is bad. I have seen bad wires before.- Usually a Nick in a wire that causes a break somewhere. But that's fairly rare and easy to spot if you suspect it of being bad.

Other than that, I would look at how it's being inserted into the speed controller. With some controllers, it's real easy to insert it wrong (either missing the connectors in the victor, or plugging it in backwards)!

[eneubec1]

We tend to use victors. No preference, its just what we have accumulated over the last 3 yrs.
The intermittent connection last year was definitely with a victor.

[JasonBecker]

As you have said, it is very coincidental that all 6 wires would be considered 'bad'. If it was the same motor controller for each wire I would definitely check that it was connected properly.

If the controllers are receiving no input it may even be a code issue.

[MrForbes]

Do you have any other cables that seem to work better? If so, compare the ends, see if the pins on the "bad" ones are extra thin, or something. I've noticed that some of them have fatter pins than others, and the skinny pins are hard to get plugged in correctly, or they just are not big enough to make good contact.

[Greg Needel]

In your Kit there was a bag that was donated by REV, with 8 brand new PWM cables. These are 22awg, which is on the thicker side of things as normally you see 24 or even 26 awg cables of this size. I would recommend using these first, before you try old ones as each one of these is tested at our factory before we put them in the Kit of Parts.


If you find that any of the new ones are bad, send me a PM and I will personally send you some new ones.

I will also second what others said about it being the motor controller itself, the old Victors are difficult to get the wire in AND tell if it is all the way seated in the connector. (this is one of the reasons we went a different direction with our cable retention on the SPARK).

[eneubec1]

Thanks for the guidance and advice.

[Ether]

Originally Posted by eneubec1

We are a team entering our 3rd year and my electrical team this year handed me 6 PWM cables and told me "these are all bad".

Could you ask the person who told you they were all bad to post here and tell us how that diagnosis was made please?