Reed switch question

[paulmcconnon]

Troubleshooting no solenoid click on 93 marathon cart.
Battery pack voltage going into reed switch on charger plug but not going out. Read on the forum that I can bypass it with a wire to battery + from white wire coming out of reed switch. It said I should use a fused wire. As I did not use a fuse my f/r burst into flames.
Next attempt in process, tore out the burnt wires and would like to know where the new bypass wire goes to . Was it to one of the micro switches on the f/r?
Also why did I burst into flames, I am guessing this bypass wire should not have gone to battery +. A litlle help goes a long way when I am stuck.
Paul

[gotmud10]

the bypass wire goes from the microswitch directly to battery 1's positive terminal...when all is done, you will have the black wire from charger port to battery 6's negative post. White wire from charger port goes to battery 1's positive. Then you will ignore the red wire (reed switch wire) and jump from microswitch to postive terminal of battery 1.

[rib33024]

If it's a marathon it does not have a reed switch,, check the micro switches on the F/R switch, check to see if you have 36 volts at the two small post on the solenoid, lets us know what you find

[JohnnieB]

Here is a schematic for a Marathon controller cart with the solenoid activation circuit highlighted.

[paulmcconnon]

Ok all here is what I have....
Obviously this cart is kind of a frankencart so keep that in mind.
I have reference voltage from:
Battery+ terminal to Key side 1 and 2
F/R micro side 1 and 2
Pot box micro side 1 and 2
Both solenoid small terminals
Controller b- terminal and PIN 1
---------------------------------------------
Next I have 3.2v to B+, A2 and M- on controller
---------------------------------------------------
From the battery NEGATIVE terminal I have reference voltage at the solenoid large terminal battery side and 4 volts under reference on controller side of solenoid. Also 4 volts under reference at controller B+, A2, and M-

All above read with key on and in forward with accelerator pressed.

Lastly in neutral the battery + terminal to controller side of pot box micro is 2volts below reference voltage.
Any ideas on why it's not running are welcomed.

[JohnnieB]

Unless otherwise stipulated, all voltages should be measured with the DVM's negative test lead attached to the main negative terminal (B-) on the battery pack.

With key ON, F/R in F and throttle pedal pushed, you should have B+ (38.2V for a fully charged 36V battery pack) on one of the small terminals on solenoid.
IF you do and the solenoid isn't activating (clicking) either the other post is not connected to B- (bad wire?) or the solenoid is bad.

There is a 250 Ohm resistor across the solenoid's main terminals, so getting a voltage 3V-5V less that B+ is normal on the solenoid's controller side terminal when the solenoid is not activated.

Get the solenoid to click, then we can troubleshoot the high current loop if needed.

[paulmcconnon]

Ok. After double checking the wiring for the solenoid circuit 3 times I discovered that the wire for the key was connected to the - end of battery pack instead of +. Now it is on + and solenoid is clicking.
I have the manual from this website for ezgo electric but it is for 2001 and up. Mine has an older controller than the 1206 that is in the manual.
Posts on controller are M-, B+, B- and A2. Also 1,2 and 3 pins. I have my pot box hooked up to ( White on 1, Black on 2 and ms blue wire on 3 ).

[JohnnieB]

Originally Posted by paulmcconnon

Ok. After double checking the wiring for the solenoid circuit 3 times I discovered that the wire for the key was connected to the - end of battery pack instead of +. Now it is on + and solenoid is clicking.
I have the manual from this website for ezgo electric but it is for 2001 and up. Mine has an older controller than the 1206 that is in the manual.
Posts on controller are M-, B+, B- and A2. Also 1,2 and 3 pins. I have my pot box hooked up ( White on 1, Black on 2 and pot box wire on 3 ).

You have a 1204 controller.
The schematic I posted earlier was for a Marathon with a 1204 controller

Jack the rear wheels off the ground (Jack Stands) so the half ton cart doesn't take off unexpectedly and run over someone or something.
Measure the voltage at M-.
Press throttle until solenoid first clicks.
You should have FULL battery pack voltage.

If not:
There is a bad high current cable, connection or set of contacts.

If so:
Slowly press pedal to floor,
The voltage should smoothly decrease to near Zero and the motor should be spinning.

If not:
Pull the small black and white wires off the controller and measure between them with an Ohmmeter.
Pedal up should be about Zero Ohms and pedal down should be about 5,000 Ohms.

Let us know what you find and we'll proceed from there.

[paulmcconnon]

Battery pack negative to M- at solenoid first click = full reference voltage.
Pressing pedal to floor = no change in voltage.
Pulled white and black wires off controller and tested ohms. 0 at no throttle and 2700 at full throttle.
I surmise this means my pot box is either bad or ?.
This pot box has 4 wires - 2 to controller and 2 to ms on f/r.
I recently purchased one with only the black and white wires on it as well as a tiny plug with I believe 3 pins on it. Can this be used to replace the existing pot box and if so how to wire it.

[JohnnieB]

Sounds like the pot box is in the half speed reverse mode.
When the microswitch on the F/R is closed, a fixed resistor is placed in parallel with the 0-5k pot, turning it into a 0-2.5K pot for half-speed reverse.
Disconnect the wires going to the F/R from the pot box and it should read 0-5k.

However, with a 0-2,700 Ohms at the throttle input to the controller, the voltage between M- and B- should dropped to about 1/2 of the pack voltage, so the controller isn't doing what it is being told to do, so it might be bad.

One more check to be sure.
You should have B+ on the third small terminal on the controller. (Blue wire to pedal microswitch)
If it is there, (Key = ON -- F/R = either F or R) the controller is bad.

-----------
I'm not familiar with all the different pot boxes out there. Where do the three wires go to in the pot box?

All that is really needed from the pot box itself, is the two wires that connect to the throttle input pins on the controller.