good voltage cart won't move

[swsawyer@reagan.com]

Basic Info:
2010 CC Precedent
3 y/o battery pack, consistently holds 50.5 volts
600 amp Navitas Controller with Madjax OTF Programmer (recent dealer install)
400 amp solenoid
Stock motor
6 inch lift, 22 inch tires
Rear Seat

Remaining planned upgrades:
2 gauge battery cables
winch and brush guard
lithium battery pack (one day, when the prices have dropped more)

Issue:
Drove about 300 yds one day, inching along following my daughter on her bike, when I heard/felt (not sure which) a “bump” and the cart stopped. Towed it back home and went inside. A couple hours later, when out to push it into the garage and tried the accelerator (just in case) and low and behold it started moving. I checked voltage (good), checked battery connections (good), so I figured the controller had gotten hot (it seemed to work again after cooling down).

Since I was looking to upgrade from the stock controller anyway, I saw this as a good opportunity to gain approval from Household 6. Over the next 2-3 weeks, anytime I drove slowly around the yard, or with my daughter sitting in my lap steering, the same thing happened again, every time. I got the go ahead from HH6 to upgrade the stock controller to the Navitas, so I ordered one and had the dealer I purchased from install it. Initially, it seemed that this had “fixed” my problem, but it didn’t. Seeking advice and counsel from the good people here on BGW, I installed a 400a solenoid, since the dealer did not, when installing the new controller. After taking pictures of the original solenoid to ensure I got the wires back where they belonged, I put everything back together (feeling a bit of swagger for not having any excess parts when I finished (I am not a natural mechanical type)) and pressed the accelerator….. nothing happened. I double checked my connections (good and tight), voltage measured 50.5v.

Now, given I have already stated that I am not very mechanically inclined, I am a pretty decent analytical thinker, and I have deduced the issue must (probably) lie(s) with the stock motor. Am I on the right track? I was not “planning” on a motor upgrade, but will happily do so, if it will get my cart moving again.

How do I check to see if the motor is getting juice? How much juice should I see on the multi meter?

If the problem is "probably not the motor", any ideas on where it might be?

As a last resort, I was thinking about seeing if one of my local cart dealers would take my stock controller, on barter, to help diagnose the problem. Or, am I being too optimistic?

Any and all help, guidance and positive thoughts are much appreciated. I apologize for the long post, I just wanted to provide as much detail as I can.

Sean

[NoleFan4Ever]

NICE write up and PLENTY of details.....

Do you hear a "click" under the floor board when you depress the Go Pedal? If so, do you hear the solenoid click that you just installed?

It is important you listen very closely for these clicks. (And the solenoid will not click if you do not get the click from under the floor (MCOR))

[Sergio]

The most logical guess is that something is installed wrong with the Solenoid.

Hopefully You disconnected the batteries so no possibility of a short damaging the Controller.

Driving slow with Sepex motors like you have is hard on the Motor and Controller as the Motor field coil can get hot very quickly which increases its resistance and reduces its current carrying capacity which causes the Armature to use more current to generate the same amount of torque.

Maybe turning the "Speed" dial on the Navitas would help, but I would ask their tech support for recommendations for slow driving.

What kind of Solenoid did You get?

Did it have a built in diode or did you add one (check polarity)?

[swsawyer@reagan.com]

Thanks for the quick feedback to both of you.

Listening is kinda difficult, for me, as I am deaf in one ear (too many tanks and machine guns over the years), but I will TRY to listen for the clicks.

To answer the Sergio, I had not thought about the polarity on the diode (external) but will check it this weekend.

Thanks again.

[swsawyer@reagan.com]

Update: I was mistaken, instead of a diode on the new HD solenoid, it was a resistor; i.e. no directional markings and current flows both ways. The resistor is a “Ohmite 40J470E” 10W 470 olms. I pulled the new solenoid off and checked resistance on it too, it measured similar to the old solenoid resistance numbers, too.

I put everything back together, lifted the rear tires off the floor, and pressed the accelerator. I did hear a click when the pedal was activated, but the wheels still did not move.

I failed to answer Sergio’s comment, yes, I did disconnect the battery pack, before starting. I failed to notice the name on the solenoid before putting it all back together but, the box says “5722 Solenoid, 48v, 4P, CC-UP E DS, Prec”.

Any more ideas? Thanks, Sean

[NoleFan4Ever]

Originally Posted by swsawyer@reagan.com

Update: I was mistaken, instead of a diode on the new HD solenoid, it was a resistor; i.e. no directional markings and current flows both ways. The resistor is a “Ohmite 40J470E” 10W 470 olms.

That is the pre-charge resistor that runs accross the 2 large posts.

Originally Posted by swsawyer@reagan.com

I put everything back together, lifted the rear tires off the floor, and pressed the accelerator. I did hear a click when the pedal was activated, but the wheels still did not move.

Was that MCOR under the floor you heard click or was it both that AND then the main solenoid you also heard click? Should be one right behind the other and the main solenoid would be a loud click. (I am trying to determine if your solenoid is closing in or not - as it could very well be a bad solenoid or an issue with the install.)

[swsawyer@reagan.com]

Yes, the resistor is running across the two large posts.

The only click I heard was at the foot pedal, and it was soft. I did not hear anything near the battery pack and/or controller, definitely not a loud click.

[NoleFan4Ever]

Ok, lets see if you are getting the inputs to the solenoid:
(Cart jacked up, key on, rocker switch in Fwd, and pedal depressed)
At the solenoid small posts do the following:
1- Take your DVM and place the red lead on the solid blue wire and the black lead on the main pack negative. You should get 48vdc
2- Next, take your DVM and place the black lead on the blue/white stripe wire and the red lead on the main pack positive. You should get 48vdc
If you are getting those then solenoid should be closing. If it is not, remove the wires from the 2 small posts and check for continuity across the 2 posts. If none, the energizing coil is bad and the solenoid needs to be replaced. If the coil shows continuity, but the solenoid is not closing, tap on the side of it gently and see if it actuates, if it does not, then you will have to replace it. (Also double check all your wiring connections to it. Maybe post a picture of it wired up so we can see it.)

And with a 400a solenoid, you will definitely hear it when it closes!

[swsawyer@reagan.com]

I think I can follow those directions, if you can give me one more piece of advise....

In order to get to the solenoid and controller, you have to take out the middle two batteries. How do you make these checks with the batteries unhooked? And I don’t see a way to reach those places from underneath, either. Or, am I totally messed up trying to follow you?

[NoleFan4Ever]

When you take the T-40 out the tray I "believe" you can lift it just far enough to access it. Not sure if the inspection cover above the motor gets you there or not. I have a DS!