New controller- how to make sure you aren’t about to fry it

[RJM]

Afternoon,

I’m wondering what checks I need to make to ensure that a new controller going in an IQ Plus cart doesn’t get ‘fried.’ I’m not sure what caused the previous 1520-5501 to die, all pin inputs seem to be testing correctly. Wires are in good shape and connections clean, including on the motor. I wanted to do what I can to check the higher voltage connections with a VM before installing a new controller. Any thoughts?

Thanks,
Ray

[Volt_Ampere]

Biggest risk to controller (assuming all connections are correct) is a bad motor. Sometimes a bad motor will kill the controller.

[scottyb]

Buy an Alltrax controller. It's the only one with reverse polarity protection on the input and the output. With a 2 year no questions asked replacement warranty.

Had a customer yrs ago connected the main battery + and - to the solenoid mains.
When the solenoid clicked it blew the top clean off. Alltrax controller was fine.

[Fairtax4me]

Biggest thing is to check the motor for continuity and make sure the motor cables are not damaged.
A shorted motor absolutely 100% WILL take out a Curtis controller. Not sometimes. Every time.

With all cables removed from the motor check the studs for any looseness or evidence of burning or other damage. If any are loose, or look discolored or the insulators around the studs are damaged remove the motor and have it rebuilt or replaced.

With a multimeter set to test continuity
A1 to A2 post, you should have continuity.
F1 to F2 post, You should have continuity.
Any A post to Any F post, you should have NO continuity.
Any A or F post to the motor case (use an unpainted part of the case) you should have NO continuity.
If any of the tests fails the motor needs to be removed for repair or replaced.

[WalterM6]

And after you have tested all of the things FairTax mentioned connect two batteries as shown in the diagram and see if the motor runs. Don't forget to put your car up on blocks. If it runs you're good if it makes a big spark your motor is shorted.

[RJM]

Thanks very much, all! Great advice, I will follow. Much appreciated.

All the best,
Ray

[RJM]

Hey guys, motor checks out fine!

Is there anything I should be checking on the solenoid to make sure that isn’t going to harm a new controller. Here is the current wiring on this iq plus, but I am not sure if it was part of the prob.

I’m not sure about the red and pink wires going into the big terminal on the battery side?

[Fairtax4me]

Pink is power to the Tow/Run switch and then key switch and everything else.
Red may be 48 supply to a reducer. Not sure. Unlikely it would do anything to affect the controller.

What does appear to be missing is the pre-charge resistor across the large posts and the diode on the small posts. The IQ plus cars may not have had the resistor, I'm not 100% sure on that.