48 volt cart Main Solenoid will not click in

mattoxh

I just replaced the controller and the cart ran fine. The next day it won’t budge. Brand new Trojan Batteries, fully charged. The two small terminals on the 400 amp controller are connected to pin 1 and pin 17 on the controller. Pin 1 has pack voltage with accelerator pushed. I assume the issue is with pin 17. I removed all the wires and cables from the the large lugs and connected full pack voltage to the small terminals and it clicks in and hold with no issue. The emergency brake is released. Does anyone have any suggestions. Thanks in advance.

BGW

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BobBoyce

You need to be VERY careful probing controller pins. The pin 17 connection is not just an output to toggle the solenoid on and off, it is also a status input to monitor the state of the solenoid. If it detects B+ when the key is turned on, it knows that the main coil is not open, ect. Probing those pins with a DVM can produce signals that are not valid.

Modern computerized controllers are not the same as the older TTL Logic controllers of the past decades that had much simpler logic. I was involved in that logic transition. Input impedances increased by large margins, and the voltage levels that could be interpreted as logic highs has decreased by more than half. The high impedance probe to probe potentials of a DVM in low ohms can affect the status of an active controller input.

Bob

mattoxh

Thanks for your reply. Maybe you can answer a question regarding the main solenoid. The small wires are connected to pin 1 and 17. Pin 1 is from the switch and carries full pack voltage which would be +. If Pin 17 is Pack voltage+ where is the solenoid getting the - or ground. When I rest I remove all wires and cables and energize with 48 + and - and it energizes and holds. Thanks

BobBoyce

When a modern controller is powered up (by turning on the key with some, by switching run/tow to run in others), it goes through a POST (Power On Self Test), very similar to turning on a computer. If all tests pass, it will typically power up the solenoid. It does this by enabling the solenoid - to connect to battery pack- via a solenoid (or main coil) FET (Field Effect Transistor). So if solenoid - is not connecting to battery pack -, there is likely something that is not passing the POST. If you just jumper solenoid - to battery pack -, then you will set another error condition. It detects this as the Main Coil FET being stuck on, ie Shorted. You must disconnect the wire to the controller (pin 17) from the solenoid before connecting it to battery pack - in order to continue your testing. Do not bypass the controllers solenoid - wire for long, as many of these 48V carts are running 36V solenoids, being PWMd from 48V down to 36V by the action of rapidly pulsing pin 17 to battery pack - in a timed fashion in order to limit average voltage to the solenoid to its rated voltage.

I suggest that you download the service manual for your cart/controller from the stickies above, and follow it to the letter, if you do not have a diagnostic handset or station for your cart. These modern controllers are very easy to damage by not knowing the correct diagnostics procedures.

You might as well tell everyone else here the year and model of the cart you are working on. I already know. LOL

Bob

mattoxh

Thanks Bob I was holding off on providing too much info some people go into shutdown mode when you mention R&T. It is a 2009 4 wd. I am not sure why they get such a bad rap possibly since wiring diagrams are non existent. There is only so many ways to build a Golf Cart. This is my first experience with a cart that has a controller. It is a mystery to me. I replaced the Curtis 1268 controller in September also Batteries. It ran like a champ until it stopped last week. I took the car it back to my mechanic and he replaced the new controller with the old one which he had rebuilt. We checked the ITS the main solenoid, the speed sensor on the motor and the motor all testing good. A couple days after the controller was replaced it stopped again. The solenoid won’t click when the accelerator is pushed. The solenoid check out fine when the wires are removed and I jump it with the battery pack. I went through Curtis diagnostic procedure and the only reading that was a little off is pin 17 reads 45.7 volts which is less than pack voltage. The walk away relay may be an issue but I check the voltage on each pin associated with it and the voltage checked out. I have too much invested in this cart to trash it.

BobBoyce

Yea, I would not recommend to trash it either. Please keep in mind that rebuilt controllers are repaired controllers. All of the parts in the controller are of the same age, so when one part fails and gets replaced, another one fails, and so on. The solenoid output of the controller you are working with may be set for the wrong output voltage, which would give you that erronious voltage reading. That is set in the Driver parameters for the Main Coil Driver. Like I mentioned before, if a solenoid had been changed for a different voltage one, the shop could have gone in and edited those parameters. It takes a handset or programming station to connect to the controller and go in there to check the settings.

1268 controllers with the correct suffix codes are sorta difficult to find. If all else fails, you may be able to use Alltrax SepEx controllers. You may be able to integrate the throttle signals so that both Alltrax controllers work together seamlessly for 4WD. If not, maybe just get it running in 2WD first with each axle. It's definitely worth saving!

Bob

Redhorse34

Hey Bob, I hope you’re doing well. Just wanted to see if I can send you my controller to be adjusted? Would like my cart to go about 25 mph or so. Thanks, Darryl



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mattoxh

Thanks again. I don’t have a handheld programmer and it is difficult to find someone that really understands A Ruff & Tuff and how to work on it.

BobBoyce

It's like any other cart in that it has a lot of basic systems combined to create the whole. I've worked on lots of things that manuals are not available for. But my niche is usually in aerospace.

BobBoyce

usgicollector is helping me communicate along those lines while I am recovering. He'll contact you.