2005 EZGO TXT Repair / Upgrade Project - Thoughts on Controller Options / General bui

[MantaRay12]

Originally Posted by JohnnieB

The voltage on Pin-4 ought to be FULL pack voltage. Get that corrected and the controller might start working right.
Voltage to Pin-4 starts at main positive on battery pack, through reed switch, through MS-2 on F/R assembly, through keyswitch, through pedal switch, connects to one side of solenoid coil and then paralleled to Pin-4. Four sets of switch contacts and over a dozen wire connections, any of the could be causing the voltage drop, maybe more than one.

JohnnieB,
you got me thinking, so I re-ran some tests. The #'s I posted yesterday are from a few days back. Here are some fresh stats. Our Pin 4 started fluctuating again in voltage, then miraculously held steady @ reference voltage. I walked away, came back an hour later and still the same readings. I did go through the line to jiggle connections (with the exception of getting behind the key to check things out). The other day, I was getting voltage fluctuation in Pin 4, the wheels would move slightly then shutter, then higher voltage spikes would move them more, then no movement, yet voltage fluctuation still present. Now I've got reference voltage, and absolutely no wheel movement, so go figure :). Stats are attached below, am I'm curious to see if you still think it's a wiring problem, stock controller problem, or maybe a mixture of both or even ITS related. I still have not inspected the Pedal Box yet, but plan to do so here this afternoon. Your tech genius is appreciated.

[JohnnieB]

Originally Posted by MantaRay12

JohnnieB,
you got me thinking, so I re-ran some tests. The #'s I posted yesterday are from a few days back. Here are some fresh stats. Our Pin 4 started fluctuating again in voltage, then miraculously held steady @ reference voltage. I walked away, came back an hour later and still the same readings. I did go through the line to jiggle connections (with the exception of getting behind the key to check things out). The other day, I was getting voltage fluctuation in Pin 4, the wheels would move slightly then shutter, then higher voltage spikes would move them more, then no movement, yet voltage fluctuation still present. Now I've got reference voltage, and absolutely no wheel movement, so go figure :). Stats are attached below, am I'm curious to see if you still think it's a wiring problem, stock controller problem, or maybe a mixture of both or even ITS related. I still have not inspected the Pedal Box yet, but plan to do so here this afternoon. Your tech genius is appreciated.

The "Honey-Do" list caught up with me yesterday afternoon.

As for thinking it is a wiring problem, I'm a troubleshooter, not a guesser. If something is being told to do something and it isn't, it is bad, but the controller wasn't getting full pack voltage on Pin-4, so it might not be being told to pass amps to the motor. Low voltage on Pin-4 is an identifiable issue that needs to be corrected.

The new voltage data provided identified another voltage issue that is very likely to be a wiring issue.

B+ to M- should read Zero volts when the solenoid clicks and increase to near full pack voltage as the pedal is pushed to the floor.
B- to M- is the reciprocal. It should read full pack voltage when the solenoid clicks and decrease to near Zero as the pedal is pushed to floor.

The B- to M- voltage reading when the pedal is up indicates something is amiss in the high current cables, their connections, high current contacts in the F/R assembly or the motor. That is another identifiable issue that needs to be corrected.

The Pin-2 voltage isn't right (Ought to be 9.0v - 11.5V for a Curtis 1206 series controller) but the voltage at Pin-1 is varying as it should, if you have a Curtis 1206 controller, so it may or may not be an issue.

[MantaRay12]

Originally Posted by JohnnieB

The "Honey-Do" list caught up with me yesterday afternoon.

As for thinking it is a wiring problem, I'm a troubleshooter, not a guesser. If something is being told to do something and it isn't, it is bad, but the controller wasn't getting full pack voltage on Pin-4, so it might not be being told to pass amps to the motor. Low voltage on Pin-4 is an identifiable issue that needs to be corrected.

The new voltage data provided identified another voltage issue that is very likely to be a wiring issue.

B+ to M- should read Zero volts when the solenoid clicks and increase to near full pack voltage as the pedal is pushed to the floor.
B- to M- is the reciprocal. It should read full pack voltage when the solenoid clicks and decrease to near Zero as the pedal is pushed to floor.

The B- to M- voltage reading when the pedal is up indicates something is amiss in the high current cables, their connections, high current contacts in the F/R assembly or the motor. That is another identifiable issue that needs to be corrected.

The Pin-2 voltage isn't right (Ought to be 9.0v - 11.5V for a Curtis 1206 series controller) but the voltage at Pin-1 is varying as it should, if you have a Curtis 1206 controller, so it may or may not be an issue.

Thank you sir for that feedback. So I've got a complete set of cables on order per my upgrade plan. As I wait for those to arrive, I'm following through on following the Pin4 voltage issue by checking connections & continuity. I'm stuck @ reed switch. Are they typically located in the charger receptacle or can they be found elsewhere. I ran a search on what I should be looking for, but I'm not exactly sure what I'm looking for to check it. Below is a pic of my charger receptacle box opened. Am I missing something? I've read sometimes people will bypass it, so I'm wondering if the previous owner may have done just that. Please advise.

[JohnnieB]

Originally Posted by MantaRay12

Thank you sir for that feedback. So I've got a complete set of cables on order per my upgrade plan. As I wait for those to arrive, I'm following through on following the Pin4 voltage issue by checking connections & continuity. I'm stuck @ reed switch. Are they typically located in the charger receptacle or can they be found elsewhere. I ran a search on what I should be looking for, but I'm not exactly sure what I'm looking for to check it. Below is a pic of my charger receptacle box opened. Am I missing something? I've read sometimes people will bypass it, so I'm wondering if the previous owner may have done just that. Please advise.

Your reed switch has been bypassed.

The next place to check is the in-line connector shown in your picture.
I had that connector fail when I was out in the middle of nowhere. Fortunately, I had a pair of nail clippers with me.

[MantaRay12]

Originally Posted by JohnnieB

Your reed switch has been bypassed.

The next place to check is the in-line connector shown in your picture.
I had that connector fail when I was out in the middle of nowhere. Fortunately, I had a pair of nail clippers with me.

OK, so I have a troubleshooting update so let me lay out the scene. Since my pack voltage was getting lower during my last testing procedures last week, I decided to start from scratch. I charged the Pack 2 days ago and let things rest for a day, then proceeded to go back through the motions, with the target of chasing down why Pin 4 voltage was not at reference voltage. Here’s my summary:

Post 1 Day Charge @ rest:
38.4 – Pack Voltage
38.4 - Battery B- to Bat Side Solenoid
37.8 - Battery B- to Contr Side Solenoid
37.8 - Battery B- to Contr B+
37.8 - Contr B- to Contr B+
Solenoid Engages = YES

Now after testing simple motor function etc., the Pack Ref Voltage Dropped to about 38.0 to 38.1 sustained, so I proceeding troubleshooting Pin4 voltage issue I was having previously. Now prior to charge, I did conclude Continuity on the following:
Solenoid
Charger Wires
Red Wire from Reed Switch Bypass
Connection Points @ Charger & Key switch connection
MS-2 F/R & MS / Pedal Box
Pedal Box Black to Control Harness Black
Pedal Box White to Control Harness White

So JohnnieB, your comment of “if something is being told to do something and it isn't, it is bad” was digging into my soul (By the way, JohnnieB, I used that line in a meeting earlier this week so thanks for that phrase of simple yet foundational logic). Now back to the Pin4 voltage issue. I measured out @ 37.8V from Battery B- to Pin 4 with Solenoid Engaged So I decided to trace this along the path I’m assuming this was the correct way to go. With the Solenoid engaged, Bat B- to the following : Positive Terminal, White Charger Positive Pin, Red Reed Bypass Ring Terminal, Red Connector, MS F/R Red Terminal, MS F/R Blue Terminal, Green Key Switch Wire, Key Switch Terminal Blue, Pedal Box MS Green Terminal, & Pedal Box MS Red Terminal All Came in @ 37.8V along the line.

Now here is where I had an “ahaa” moment digesting your comment. When Pedal was fully engaged, Voltage was still fluctuating @ Pin4, just like previous measurements last week before my recent charge. Values were between 35.4V & 36V. The same fluctuation was also occurring at all measurement points in the line. Hmmmm.. So maybe all points in the line are “Not being told what to do because of a bad battery cell perhaps? Not sure, and I’m no battery expert. I’m attaching Battery Stats in the below Grid (also note my reference voltage did drop when I performed this test).

What do you think? Battery # 1 & # 3 are looking suspect? Or is this normal? At this point I’m beginning to think my pack has been the root cause all along. What are your thoughts on this latest data set and my above observations? I feel like I know way more about this cart now then 3 weeks ago. Am I on the right troubleshooting track here?