DOH! EZGO Battery polarity connected backward to PDS controller!

[Old Foogie]

Yep, the Dufus bug jumped out and got me. I have a 2007 EZGO PDS cart. When I put the batteries back in the cart for the start of camping season, I connected the leads to the controller backwards. I saw a very small spark when I made the last connection to the controller but figured it was just a capacitor powering up. I put the seat on, put in the key, set the switch to reverse, turned on the key and nothing. Not even the backup beeper. I pushed in the accelerator and nothing. I tried it in forward and nothing. I turned off the key, pulled of the seat and found the cables connected wrongly. The cables were very warm when I switched them to the correct battery terminals. I put the seat back on and still had no movement or reverse beeper.

How should I proceed with trouble shooting to figure out what I have ruined?

Thanks

[Volt_Ampere]

Yes. But you can count on replacing your controller.

[scottyb]

Yeah, probably the controller is gone but the micro switches and reed switch may be gone too. You will have a bit of trouble shooting with the meter to figure it out. Here is the diagram for your cart

[Old Foogie]

Thanks for the diagram scottyb. I do not get a click from the solenoid when I try to get the cart to move. I can hear/feel a light click from the accelerator pedal when I depress it. One thing I am going to do is upgrade the battery pack wiring to the controller to 4 gauge. After reading a few posts here I started the troubleshooting by checking the reed switch. I think the reed switch has been removed, please see the attached Charger Receptacle picture and see if I am correct.

My battery pack is at 37.1 volts after sitting this past winter. I checked the voltage from the positive side of the solenoid to the pack and it is 37.1. I checked the motor side of the solenoid to the pack and it is only 1.9 volts. I read the following in the EZGO Diagnostics sticky thread of yours, "Place the (+) probe to the controller side of the solenoid's large post. The reading should be 0.1 to 3 volts less than battery voltage. If the reading is more than 3 volts less the battery voltage, the resistor is faulty. If the voltage is the same as the battery voltage, replace the solenoid.".

So it looks like the resistor is bad. It does look like the resistor has been hot and laying against the A1 wire to the controller. Please see the picture Resistor Vs Wire Insulation.

Do I need to hold off on troubleshooting until the resistor is replaced, or are the other tests I can do with the resistor as is?

Thanks.

[rons]

Looks like we both have the same issue i just posted the same thing for my 2002 txt pds cart i have tried some similliar things as you is there a way to test the controller? i have 36+ volts on both sides of my solenoid also no buzzer and no reed switch?
check out my post as well to see what others are saying to check


Ok so lets start i am a dumb rearend i was replacing all my batteries on my golf cart a 2002 ezgo txt pds cart and hooked them up wrong when i conected the batteries wrong my my solenoid made a poping noise and there was a burning smell and a little smoke I immediately unhooked the wires and then pulled of the cover on the controller and solenoid and i started to check all the wires going into the solenoid they look fine the plastic was slightly melted on the red wire going to the first (large post) of the solenoid it looks like any wire that was leaning up against and touching the solenoid had a small burn on the plastic coating of the wire there was no wires that were completly burened through to the wire. So i re-routed and re-conected the battery cables corectly and the cart wont do anything at all.

Because i suck at electricial i decieded to read up on what i could on the forum and test it. Here is what i did
Quick side note my reverse buzzer has also stopped working so i cant run a pds diagnostic check it did work prior to me hooking up the batterys incorrectly.

Here is what i found i tested the batteries and have 37.9volts and at the solenoid i have 37.9volts on the battery side post and 37.3volts on the controll box side post i also checked the volts at the controll box and i am showing 37.3volts at the top b+ post of the controll box and 37.9 at the micro switch at the pedal this switch is also clicking when the pedal is pressed and the other side of the switch is @ 0.00 volts and when the pedal is pressed it goes to 37.9volts.

And i also have no noise at all comming from the solenoid (should there be a clicking noise is it stuck open). I have also checked the diode on the solenoid at the battery side it is 37.9 volts and after the diode on the controll box side it is 37.3volts. I am unsure what i blew up and dont know where to start solenoid ? controll box? micro switch at pedal? the forward /reverse switch? Motor?

Any help would be great before i waste $ replacing parts that dont need to be re-placed.

Thanks,
Ron

[Old Foogie]

rons - I did see your thread before I posted last. I will keep an eye on your post too.

Thanks.

[yurtle]

I'll let Sepex experts comment on troubleshooting, but yes, your reed switch has been "bypassed". Actually, it's been removed, and wired the same way I did mine, assuming it plugs into the spade connector in the pic.

[JohnnieB]

The PDS is a fly-by-wire system. Meaning the controller controls solenoid activation, the reverse beeper, the direction (and amount) of current flow in the motor's field windings, the amount of current flow in the motor's armature windings and when regen braking occurs and the amount of regen braking. The various switches and throttle, tell the controller what to do and the controller does it, unless the controller is bad.

The switches can be checked by unplugging the plugs from the controller and measuring continuity between the pins the switches are connected to with an Ohmmeter.
Jack and Pin numbers for the various switches are shown on the schematic Scotty posted.

The reason you get 37.1V on battery side of thew solenoid and 1.9V on the controller side is most likely because something major in the controller is shorted out and about 140ma of current is being drawn through the 250 Ohm resister, so about 5W of heat is being generated, which will heat the resistor considerably.

My guess is the controller is blown, but some of the switches may have been taken out also.
The resistor may be good, but it has been hot, so check it. It should be 250 Ohms for a 36V system.

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At 37.1V your batteries are only 70% SoC and are sulfating as we speak.
Hopefully they were charged periodically over they winter, or they might be bad also.