EZGO F&R issues and wiring.

[Jblack]

So it's been a minute since I've posted on BGW. Had a gasser that I sold years ago. I recently picked up a EZGO 36V series TXT. Model # D103 so I assume a 2003 version. I don't have any history of cart since owner has passed.
Cart didn't run when I first got it. (Hadn't runs in probably a couple years) Has newer Duracell pack. Got the cart charged 39-40 volt's when topped off. Cart moved as it should for a few days. Then the intermittent "no-go" in forward started to happen. Solenoid clicks every time. I tore apart the F&R switch and it had been overheated a few times based on the black contacts and burnt fiberglass on the rotating portion. The plan is a complete resto over the winter, but was hoping to get it running until then. I cleaned and sanded all of the contacts and made sure they weren't sunk into the board and put it back together. It worked great for a day and then it wouldn't go forward again.
So I wanted to start checking the high amp wiring thinking I could have a bad cable etc. I searched for wiring diagrams on the site and I couldn't find one that matched how this cart is wired. the Series TXT solenoid activation circuit was the closest I could find, but my routing is different. I might have the motor inputs wrong, as I wasn't sure which post is which on the actual motor. Also I marked the wires based on the F&R orientation, with the top post being the one marked "C".
Obviously the cart works with this wiring, but since I'm not an Elechicken, I don't want to let the smoke out of this thing, by connecting it up wrong!
Any comments would be great!

[Sir Nuke]

the way your cart needs to be wired is like the diagram on the bottom.

[Jblack]

Thank you Sir. That was my assumption, but I'm also curious if the way it is currently wired was the cause of the overheating that was shown on the F&R switch? Reason I ask is when it did work, this thing would bark the tires in both forward and reverse.

[Sir Nuke]

Originally Posted by Jblack

Thank you Sir. That was my assumption, but I'm also curious if the way it is currently wired was the cause of the overheating that was shown on the F&R switch? Reason I ask is when it did work, this thing would bark the tires in both forward and reverse.

it most likely was the overheating issue.....and the orange wire from the microswitch on the F&R to the controller is the HALF SPEED Reverse …. if its not hooked up, your cart will go the same speed in both forward and reverse.

[JohnnieB]

The MOSFETs (speed control circuit) are located between the controllers B- and M- terminals. so whoever designed the thing was thinking in electron current flow terms rather than conventional current flow terms. Apparently whoever rewired it was thinking in conventional current flow terms and thought the armature ought to be connected to B+ instead of M-.

The Armature, Stator and F/R contacts are all in series so it doesn't matter what order they are connected in, the motor will run. There are physical limitations as to where the F/R contacts are located to get the direction lever in sync with the direction the cart travels and getting the Beeper and half speed function to work when direction level is in R, but there are several combinations of wiring that will do that.


Normal forward sequence:............. M-, A1, A2, C, B, S1, S2, D, A, B+
As connected forward sequence :.... M-, A, D, S2, S1, B, C, A1, A2, B+

Note amp flow through stator is the opposite, so I suspect if the orange wire (reverse beeper and 1/2 speed) is reconnected, the beeper would sound in forward and cart would go slow.

[Jblack]

Thanks for the input Gents!

First things first I will get this thing wired correctly and then see where I stand!

Wrangling Pixies is not one of my favorite things to do. I have a healthy amount of respect for those invisible bastards. So I want to make sure everything is in order before trying to hunt down an issue.

I've downloaded the "Chapter E" PDF to start my journey

[Jblack]

Oh one more thing for this double E apprentice. In regards to the terminal connections at the motor. Are the forward terminals the A1,A2??

[JohnnieB]

Originally Posted by Jblack

Oh one more thing for this double E apprentice. In regards to the terminal connections at the motor. Are the forward terminals the A1,A2??

There are no "Forward" or "Reverse" terminals on the motor. A1 & A2 are connected to the Armature. S1 & S2 are connected to the Stator Windings.

F & R are determined by the relative direction of current flow through the Armature and thorough the Stator (aka Field) windings. If the motor shaft turns CW when current flow is from A1 to A2 and from S1 to S2, then it will turn CCW if the current flow is charge so it flows from S2 to S1.

In the early EZGO carts with resistor drives, the direction of current flow in the Armature was changed by the F/R switch assembly, in later carts with electronic speed controllers, the F/R switch changed the direction of current flow in the Stator windings.

[Jblack]

Wanted to follow up on this thread. I ordered a new HD F&R switch and replaced all the battery cables with 2ga. Everything is working as it should :D
Also I did find a wiring diagram that matched how my cart was wired. Thanks to ScottyB @ carts unlimited. 4 blade control series diagram is what I have, according to the link below
https://www.cartsunlimited.net/ezgo-...eshooting.html

next up once winter hits will be a complete teardown and resto