2000 Ezgo TXT Series drive with no reverse

noxin

I just acquired my first cart, and before any of the upgrading starts I need to get some of the basics working for cruising the neighborhood. My main issues are loose steering and no reverse. The steering I improved a little by greasing the steering rack (apparently this cart had not been well maintained). Now on to the reverse...

Here is the information I know about the cart (all 36v stock as far as I know):
Year: 2000
Model: Ezgo TXT
Drive: 36v Series
Motor: Advanced DC motors A95-4005A
Controller: Curtis 25864G05
Solenoid: SAS 4303
Batteries: (6) 6v Trojan T-105 (1 week old)
Cables: Brand new 2 gauge (full 13 piece set)

Batteries charge up fine, the cart will move in forward (though not overly quickly), and reverse buzzer will sound and solenoid clicks when pressing the pedal in reverse. I removed the FNR switch and cleaned all contacts, checked for continuity in attached microswitches.

I tried to look through some of the diagnostics to get some readings, but some of them were very strange so I assumed I was getting confused on what to measure. Here's what I got so far for voltages:

Pack: 41.7
Solenoid on battery side: 41.7
Solenoid on controller side: 41.4

Then I think maybe I was looking at the wrong set of instructions, because I thought I needed to measure these with the accelerator pressed:

Controller B(+) to M(-) in reverse: varied between 24-41.5 volts
Controller B(+) to M(-) in forward: varied between 0-200+ volts. Made me question my meter

I also verified pack voltage across the small studs of the solenoid with the accelerator pressed, but I'm not sure if I need to just focus on probably having a bad controller and test more there?

BGW

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noxin

I'm going to try to look at this again today. Should I be using the Series drive, ITS, and high amperage sections from scottyb's site here:

http://www.cartsunlimited.net/ezgo-troubleshooting.html

And can I use section E from this manual, even though it says starting with 2001 model?

http://products.jacobsen.com/img/manuals/28646.pdf

noxin

So I'm just now getting a chance to go through diagnostics, and one of the simple things I thought I would check first is the diode. Looks like the band on the solenoid diode is on the controller side and not the BL+ side.

From what I've looked at, this is wrong? Should I be getting forward motion at all if it's on backwards? I figure swapping it would be a quick test, but I'm worried if I'm looking at it incorrectly I'll screw something else up...

scottyb

DO NOT swap the diode around for a look see. You will be doing some damage.
Your assessment of what is + and - is incorrect on this one. Reversing the diode will cause damage.

noxin

I'll take your word for it, but the unbanded end of the diode is currently on the small post nearest the large post connected to positive terminal on battery pack. There's no telling what the previous owner may have done to the wiring, so I guess I need to double check everything.

noxin

Ok, so I'm colorblind and the diagnostic tests mention checking voltage to post with yellow wire, etc. =)

I'm getting pack voltage at the solenoid on the large post connected to BL+
I get about 0.5v less on the other large post with the resistor connected.
I get pack voltage across the 2 small posts when I press the accelerator (positive in the opposite direction of the diode btw)
The next step mentions the yellow wire on the small terminal, and I have none. There are 2 black wires coming from one small post and 2 red coming from the other.
When I press the accelerator and activate the solenoid, I get pack voltage from BL- to the small post on the controller side of the solenoid (which also connected to pin 4 on controller). I get nothing on the other small post that is connected to B- on controller

Hope that is confusing enough for everyone =)

noxin

Here is a picture showing the solenoid and diode, and how they're connected to the pack and controller.

Large post on the right goes to pack positive, left one to controller B+.
Small post on right goes to B- on controller

Attached Images

Screenshot_20170707-195101.jpg (88.2 KB, 0 views)

usgicollector

Looks all right to me.

noxin

Thanks! I was worried that the positive on the large post and small post needed to be the same =)

usgicollector

Does this help?

Attached Images

Ezgo Series solenoid activation diagram.jpg (107.9 KB, 0 views)