Upgraded DS trouble-shooting - things got hot

[Steveslf]

I am somewhat new to the CC-DS world. I installed the Scotty B 48v IQ upgrade and everything was working fine (except for the occasional jerky starts) when the cart stranded me a mile from home with the wife, two babies, and a puppy.

We stopped after about 3 miles of paved roads and the cart would not get going again, it just "pulsed" a bit in both forward and reverse. The solenoid was HOT, and the motor was very warm, not hot. I will admit that this particular ride we were raveling at half electric throttle. The IQ Conversion upgrade kit was a 500 AMP Altrax, Admiral A4, and a 400 Amp solenoid. I did not go crazy on tires so I used 20" turf tires.

I towed the cart home and let it completely cool down but the pulsing when the throttle is pressed remains and the cart will not move.

Is there an order of diagnostics I should try first? It is a 1991 CC-DS that I rebuilt from the frame up so I am not shy about tearing it all apart again if needed.

Any help or advise would be appreciated.

Steve

[Tom47]

It sound like you are losing voltage somewhere. Maybe a loose battery terminal or motor terminal. If the motor was hot but you were able to leave your hand on it, it's fine. 165 degrees will burn you but the motor is ok.

Get a wiring diagram which you probably already used and begin from the key switch through all operating switches and components, solenoid, etc. I believe you will find something loose. If there is a loose connection in the main power terminals, they will be hot.

Good luck and maybe someone else will offer assistance.

[Steveslf]

Thank you for the help. I will crawl into and under to see if I can find a loose connection (which is likely). I made the mistake of procrastinating on the cotter pins for the steering linkage. It was almost a disaster!

Steve

[Tom47]

Originally Posted by Steveslf

Thank you for the help. I will crawl into and under to see if I can find a loose connection (which is likely). I made the mistake of procrastinating on the cotter pins for the steering linkage. It was almost a disaster!

Steve

Maybe a good thing it quit running?!?

BTW, I forgot to mention earlier but you can adjust the Alltrax so it will give you a soft start. You can even install a personality switch to enable two settings to your liking. See Scotty about this.

I have mine adjusted so I can floor the pedal and it will just takeoff gradually with no jerk at all. However, sometimes crossing traffic I wish I had a bit more bottom end!

[BBBHC]

Do you know what your voltage was at the time it left you stranded? Could have just been low battery at that time.

I'm not familiar with Scottyb's IQ system. Does it have a run/tow switch? Did you put it in tow when you towed it?

Some pictures of your batteries and components might help us to diagnose your issue.

[Steveslf]

Thank you for your interest in helping out.

The voltage was/is just over 50V (it still has a full charge) When I try to move it drops only 1V to the mid 49.xV range. Engaging the electric pedal causes it only shudder and the cart feels like it is pulsing.

The IQ cart upgrade has a run/tow switch. I made sure to put it in Tow before dragging it home with the car.

I should be crawling around the cart this evening to check for loose connections so I will take pics of the components.

Thanks again for your help.

[Tom47]

Do you hear the solenoid energize when you push the pedal, and does it stay energized while you hold the pedal down?

You may want to raise the rear tires off the ground and try it in case it decides to take off. I know you have a new solenoid but they have been known to fail early more than later.

Hook up a good digital voltmeter across the main [large] solenoid terminals.
Check for voltage across the main terminals before and while you press the accelerator. You should read full battery voltage before you press the pedal and 0 volts after you press the pedal.

If this test is ok, I would definitely look at all the main power wires from the batteries all the way through the solenoid, controller and motor. I think you might find that loose connection. When hooking things up, it is easy to forget to tighten one securely.

Make sure to turn the run/tow to tow or remove the main + and - battery connections before trying to take a wrench to anything. Good idea to remove any rings or watch you are wearing. They conduct electricity very well.

Again, good luck!

[Fairtax4me]

The solenoid was HOT, and the motor was very warm, not hot.

This sounds like there is a bad connection at the solenoid or the solenoid was not making good contact internally. Likely the solenoid has failed.

What kind of solenoid did you get with the kit?
Are your large cables First on the solenoid posts in direct contact with the base of the post? If you have any smaller wires between the cables and the base, the connection there will overheat and can damage the post and the cable, and possibly the solenoid internals as well.

[Steveslf]

Fairtax4me and Tom47,
I will try to answer both of you in this reply:

I put the cart up on jack stands and tightened every connection on the cart. The connections for things like the F/R switch, backup buzzer, and key switch all seemed fine. The larger connections all allowed at least a little additional tightening. I also unplugged the 12V reducer to take all accessories out of play (lights only for now)

When I pressed the pedal, the solenoid did engage and one tire did spin weakly with a shudder every few seconds. The voltage between the solenoid large posts was zero before, and about 50V when engaged. There was a little voltage after the pedal was released which dropped back to zero when the solenoid disengaged.

Tom47, you wrote: "You should read full battery voltage before you press the pedal and 0 volts after you press the pedal.". I believe I experienced the reverse. Full voltage when the pedal is depressed. Is that an issue? I checked between the large solenoid posts.

I believe I have the wires stacked properly on the solenoid which is a MZJ400A. (see pics) Is there a definitive test to see if I ned to replace the solenoid?

[scottyb]

IQ conv. Troubleshooting >
Remove the diode to see if the cart runs. If yes the diode has failed.
All tests Run/tow on. Key switch on. F&R in forward. Rear wheels raised off the floor for safety.
Determine if there is 48v measured between the 2 small solenoid posts when you try to go.
If yes:
The solenoid has failed if there is 48v between the 2 small terminals each time the pedal is depressed and there is not continuity between the 2 large posts.
If not:
Unplug the pedal blue wire and determine if there is 48v (+) on the pedal side blue wire when the pedal is depressed.
If not, check the pedal fuse. If it's bad, replace it.
If the fuse is good, check the output on the pedal green wire. Meter black on the battery main - and meter red on the disconnected pedal side green wire.
The reading should be 0-4.6v when the pedal is depressed.
If no, the Run tow switch may have failed.
If yes the pedal switch for the blue wire has failed.
The solenoid is suspect if both blue and green pedal wires are operating as described above.

The IQ kit includes an in-dash digital voltmeter.
What was the standing voltage when the cart quit?
What was the under load voltage when you try to go and the cart is pulsing?
The motor can get hot (150-200 degrees) under normal use. The solenoid Should not get to much more than 10 degrees above ambient temperature.
Excessive heat is usually caused by a poor connection or low voltage.
Low voltage can cause damage to system components including the solenoid and motor.
What battery pack are you using?