'97 Ezgo solenoid not clicking & weird voltages

[tdl8956]

Hi, my '97 DCS Electric Ezgo one day stopped moving and started making a groaning sound, further testing revealed that the solenoid was not clicking, and the solenoid's small terminals read 20v instead of battery pack voltage of 36v. I tested the voltage at the motor's terminals, and when the pedal was pushed, it read 3v, but when pedal was let up, it read 36v for a few seconds before returning to 0v. The motor didn't turn during any of this. I talked on the phone to a guy from a local cart shop who said it is probably the controller or the motor, but I would much rather order whatever the new part is and do it myself than have it fixed. Thanks for the advice

[scottyb]

Attach the meter test leads to the battery pack and try to go.... what does the pack do?

[tdl8956]

The pack's voltage drops 1/2v-1v. Might I add that the direction lever was in reverse, not that that should make a difference.

[scottyb]

So when you try to go there was really no draw on the pack... with the meter, check .... there should be 36v at every place the red wires go when you try to go..... can you tell us where you are missing 36v + on the red lines and if you have 36v - at the blue line?

Lets see why the solenoid is not closing

[tdl8956]

I found that we are getting pack voltage into the controller (the red wire) but I'm having trouble understanding the diagram and where to check next. Thanks.

Edit: I just tested again and with key on, in forward position, I press the pedal. There is a 2.5 second delay until the solenoid clicks accompanied by a tiny bit of forward motion from the cart. I let go of the pedal and the solenoid clicks again. This is very weird, does anyone have any advice? Thanks.

Edit #2: Tested again, confirmed f&r micro switches are working. The solenoid will not not click. There seems to be intermittent failure of solenoid operation, and I used to think it would not click at all, hence the title of this post. I also checked voltage on M and B+ of controller, which (I think) goes to the motor. 0 volts for that. I believe it is the controller, unless there is something upstream of the controller. I have confirmed everything upstream of the controller is working other than the pedal switch.

[JohnnieB]

The first order of business is getting the solenoid to click when the pedal is pushed. Then we can troubleshoot further as needed.
(The solenoid should click if the motor is good or bad or disconnected)

Lift the rear tires off ground and place jackstands under the axles so the half ton cart doesn't take off unexpectedly and run over someone or something.

With charger disconnected from cart, Run/Tow switch in Run, keyswitch ON and F/R in Forward, you should have FULL battery pack voltage on Pins 6, 7, 9 and 10.

If not, trace the missing voltage on attached schematic.

If so, press the throttle pedal about 1/4 to 1/3 the way down.
You should now have Full pack voltage on Pin-5 and the voltage on Pin-7 should go to zero.

If not, the controller is most likely bad.

If so, the solenoid is probably bad.

[tdl8956]

Here are my voltages:
Pin 6 -29v
Pin 7 - 29v
Pin 9 - 29v
Pin 10 - Battery Pack Voltage

Might I add that the solenoid is now clicking after a 4 second delay.

[JohnnieB]

You've got probably got some poor switch contacts and/or connections and/or wires causing the low voltages on Pins 6, 7 & 9.
Pin-9 has the same voltage source as the other two, so fix it and you'll most likely fix the other two also.
Here's a schematic with voltage path to Pin-9 highlighted in red. (First attachment)

It goes through the Reed switch first, and Reed switches have lousy contacts, so bypass it. (Second attachment)

------------
The 4 second delay isn't right. Could be bad controller, could be a sluggish pedal microswitch, could be dirty contacts in the in-line connectors.

Check the voltage at Pin-5. It should jump to pack voltage instantly when pedal is pushed.

FWIW: EZGO uses the NC (Normally Closed) contacts of the microswitches they put in their carts to activate whatever they activate, so getting the cart to run depends on some itty-bitty springs inside the microswitches. (See third attachment)

The spring weakens over time and usage, and they get gummed up, so they no longer close the NC contacts instantly like they are supposed to.

The logic behind using the NC contacts is that the most common type of microswitch failure creates a disabled cart rather than a runaway cart.

[tdl8956]

I tested the the pedal at pin 5 a few hours ago after noticing it on the schematic, it jumps to around 17v and works its way up to 19.5v over the course of several seconds. I'll try to fix pin 9 now.

Edit: See here what I found in the charger receptacle. http://i.imgur.com/Nh9CtJx.jpg About to bypass it, sorry, this sidetracked me.

Edit #2: Bypassed switch, cart now moves. Can't tell you how much gratitude i feel, I was about to buy a $400 controller and all. I never would've realized it was something as simple as a little switch.

Much thanks,
Dean.

[scottyb]

That's impressive.

The cart will not run until the reed switch lead is connected to constant pack (+) voltage. The cart won't charge until you address the receptacle and maybe plug issue that caused this damage