95 EZ Go Medalist Series will not go

[BoBoMcC72]

I am troubleshooting my 95 EZ Go. It is a Series medalist. She is will not go. The solenoid clicks when the pedal is depressed. I have jumped it and depressed the pedal and still no go. my understanding is this means the solenoid is good. My voltage from batteries is good (39.4). The voltage reads right on the Solenoid as well. The Voltages on the controller read B- 0/0, B+ 37.8/39.3, M- 19.6/0.6 (normal/pedal depressed fully). I do get a transition from 5 - 0.6 on the M- as the pedal is depressed after the solenoid clicks.

From other information I have gotten, I believe my controller to be faulty. Can anyone here confirm this diagnosis? I don't want to spend that much on a part and not fix the problem.

[JohnnieB]

The voltage between B- and M- terminals on controller should be Full battery pack voltage when the pedal is pushed just far enough for the solenoid to click. Then it should decrease to near zero as the pedal is pushed to floor.

I appears that you are not getting Full battery pack voltage between B- and M- when the solenoid first clicks, which means you've got some bad cables or connections in the high current loop.

See attached schematic with high current loop highlighted.

Bad F/R contacts is a common problem in series drive carts.

[scottyb]

Is there a resistor on the solenoid ? If yes, does it get hot when you try to go?

[BoBoMcC72]

I have been having ongoing problems with wiring and recently replaced the F/R Contact board due to that. Everything worked fine for a week or two. Then I got up the other morning and she wouldn't go. All Connections and cables appeared fine the other day. I am going to double check the wiring and connections. Will check the resistor while I am at it. Thanks.

[BoBoMcC72]

Ok... I dont see that resistor, but diode checks good... Still checking wiring, but everything looks good so far...

[BoBoMcC72]

ok... I am reading 19.5 volts on the C contact of the F/R switch. When I disconnected the wire, the voltage was on the wire but C returned to 37.5. This is a point of confusion for me because B and C are electrically the same point, but read different voltages with the everything normal. Anyway... I did not find a resistor to check. All cables tested electrically sound. I am reading 19.5 V on M- with the wire connected and 19.1 V without. Roughly 24V on the cable when disconnected from M- which also made C of the F/R Roughly 24V....

[BoBoMcC72]

Oh... I almost forgot. I checked again and 19.5 jumps to 20.5 then drops immediately to 5v when the solenoid clicks. Not sure if that means anything.

[BoBoMcC72]

JohnnieB, are A, B, C, and d points on the switch shown as you look top to bottom on the switch? I am still looking but cannot find anything except my bottom and side posts appear to be the same electrical point while the top post is isolated from the other three. Is this a correct configuration? I would like to think it is as i do not see how the cart ever would have worked if that were not the case.

[BoBoMcC72]

Ok... I think i have at least part of the problem. When i rotated the F/R switch, connectivity through the contact board posts did not move. Obviously this is at least part of the problem. I took the switch apart and put it back together several times. No joy.
I will get back to you when I have more.

[JohnnieB]

Originally Posted by BoBoMcC72

JohnnieB, are A, B, C, and d points on the switch shown as you look top to bottom on the switch? I am still looking but cannot find anything except my bottom and side posts appear to be the same electrical point while the top post is isolated from the other three. Is this a correct configuration? I would like to think it is as i do not see how the cart ever would have worked if that were not the case.

A, B, C & D are the studs the cables are connected to. Approximately the same F/R assemble has been used for several generations of cart designs. It was mounted with pointed end down in Marathon carts and pointed end up in Medalist and TXT carts.

C (Top post in a Medalist) should connect to B when F/R is in Forward and to D when in Reverse.

A (Bottom post) should connect to D in forward and B when in Reverse.

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There are more than one way to connect the cables and get the motor to turn clockwise or counterclockwise and have the reverse beeper to sound while in reverse, but the way shown in the schematic will work.

If the cart has moved with the cables attached as is, the problem is in the F/RE high current contacts.

On an 18 year old cart, the whole F/R assembly probably needs to be replaced. http://www.cartsunlimited.net/F_R_Switch_Upgrades.html