EZGo Shuttle Ain't Goin'

[JohnnieB]

Originally Posted by wakeworld

Voltage decreases to around 36 volts when I push the accelerator all the way down.

That means the controller or the throttle is bad. Since you had previously tested the voltage on the White wire (Terminal-3) and got the correct voltages with pedal up and pedal down, the throttle is good, so the controller is bad.

[wakeworld]

Actually, the white wire test is the one that failed...

"everything seems fine until I get to where I put the positive lead on terminal #3 (white wire) and press the accelerator. It's supposed to slowly get up to 2-5 volts below reference voltage. However, the voltage reading goes from 0 to about 11 volts and stops there."

Plus, I've used two controllers, one that I pulled out of a working cart and another that was just rebuilt, and I've gotten the same results. I'm guessing this points toward the throttle, correct?

[JohnnieB]

Originally Posted by wakeworld

Actually, the white wire test is the one that failed...

"everything seems fine until I get to where I put the positive lead on terminal #3 (white wire) and press the accelerator. It's supposed to slowly get up to 2-5 volts below reference voltage. However, the voltage reading goes from 0 to about 11 volts and stops there."

Plus, I've used two controllers, one that I pulled out of a working cart and another that was just rebuilt, and I've gotten the same results. I'm guessing this points toward the throttle, correct?

The statement highlighted in RED, is an incorrect statement.

The correct test for the white wire is:

With the pedal pushed just far enough for solenoid to click, the White wire (Terminal-3) should read 1.6V
With pedal pushed to floor, it should read 2.5V.

What voltage do you read on the white wire when the solenoid fist clicks and when the pedal is on the floor?

If it is 0-11V, it may be the ITS sensor.

[wakeworld]

Ok, my apologies. I got some of my tests/results mixed up. Sorry about that. The results of the white wire test are 1.6V-2.72V.

The test that failed was actually the "Checking Controller Output" test. In this test, I put my positive probe on the B+ terminal of the controller and the negative probe on the M- terminal of the controller. As I depress the accelerator, voltage goes from 0 to 12 volts. However, the testing procedures say it should go to 2-5 volts under reference voltage. It tested the same way with the orange reverse micro switch wire removed. The manual says to "replace the controller" and this is why I initially sent the controller in for a rebuild.

[JohnnieB]

The controller output test in the manual (M- to B+) is more or less the reciprocal of the M- to B- test I asked you to do. I like my way better because it identifies faults in the high current cables/connections/contacts immediately, and then goes on to identify a fault in the controller's output.

The control element (MOSFETs) in the controller is electrically located between the M- and B- terminals, so it doesn't matter if the rest of high current circuit is in really poor condition, the voltage will decrease from whatever it is when the solenoid clicks, to near Zero when the pedal is on the floor, unless the controller or throttle is defective.

The throttle signal in your cart (White wire) goes from 1.6V to above 2.5V like it is supposed to, so the controller is bad.

I'd retest the ITS steps 2 and 3 on page G6 of the manual I posted, just to be sure, but step 5 is good, so I'm at least 99.9% sure the "Rebuilt" controller is bad.

[wakeworld]

The only problem I see with that conclusion is that I also tried it with a controller out of a working cart and got the same readings. :( I retested all the steps on G-6 and they all passed.

I did go to page G-8 and ran that test on the white wire in the ITS box and got some weird results, but, again, I did this on two different ITS's and got the same results on both. It says the meter should read 0.45-0.53 through 1.5 volts at full pedal. However, I got a reading of 1.55 through 2.72 volts at full pedal. Does that tell you anything?

[radioman]

If the tests JohnnieB recommended B- to M- and the ITS is inconclusive why don't you try putting the suspect rebuilt controller you are troubleshooting in the working cart you borrowed the controller from to test and see if it works in it or not. This might help prove whether controller is bad or good.

[JohnnieB]

Originally Posted by wakeworld

1. The only problem I see with that conclusion is that I also tried it with a controller out of a working cart and got the same readings. :( I retested all the steps on G-6 and they all passed.

2. I did go to page G-8 and ran that test on the white wire in the ITS box and got some weird results, but, again, I did this on two different ITS's and got the same results on both. It says the meter should read 0.45-0.53 through 1.5 volts at full pedal. However, I got a reading of 1.55 through 2.72 volts at full pedal. Does that tell you anything?

1. Are you actually telling me that you have access to a working EZGO 48V series cart with an identical controller?

If so, why may I ask, did you not check the controller output of the known good controller when it was installed in your cart, and/or test the rebuilt controller in a known good cart?

BTW: Based on 50+ years of troubleshooting experience and teaching of said subject to some of the brightest young men and women this nation has to offer, the conclusion that the rebuilt controller is defective is valid, but it is also based on the information you have provided, so I stated I am at least 99.9% sure, rather than 100% sure, because some pertinent information may have been omitted.

2. It tells me the EZGO Tech Writer cut and pasted most of page G-8 from a previously written service manual for a 36V series cart with a Curtis 1206 controller and the verification and validation process of their technical manuals is lacking.

[radioman]

It is nice to have a spare golf cart to swap parts to troubleshoot. Use care though or you might wind up with two inoperative carts.

[wakeworld]

I don't have access to another working cart. However, I do have access to another controller that came out of a working cart (but I didn't know my buddy had it until after I had mine rebuilt). Mine is a Curtis 1205-210 and the one out of the working cart is a 1205-211. I mentioned swapping out for this other controller in the original post. Sorry if that wasn't clear. When I swap out with the other controller I'm getting all the same test results.

When I test continuity on the big posts of the solenoid before it is connected, I get none. However, once I install it, I'm getting continuity even with the key off and the switch in neutral. Is that right?