95 EZGO Medalist wont go

[LOADER]

Hello all, I have a 1995 ZEZGO 36V Medalist golf cart that wont move. I have visited the diagnostics area and found all of this forum’s information to be very helpful but I have hit a snag and am now asking for ideas. The specifics are as follows. The cart always functioned ok, and never had any issues with her but a few days ago, she suddenly wouldn’t move forward or backward. The solenoid clunked every time the gas pedal was depressed but it refused to budge. I examined everything but nothing appeared burnt, broken, or loose, but trying to be thorough, I began to clean up connections (one by one) although all were fairly clean, with little corrosion and after cleaning everything up, she ran like a dream. Two days later, she dies again, wont move, still only a solenoid clunk when accelerator was depressed. I have an old solenoid in parts bin, so I try an exchange, to maybe see if this changes anything. Please understand that at this time, I hadn’t discovered this forum or all of its helpful advice so now I feel rather foolish looking back over my inexperience in diagnostics! I now know that a lot of stuff tossed into parts bins are possibly bad and I shall endeavor to empty this box to better stay out of trouble next time but the solenoid swap resulted in the same clunking noise when pedal is pushed, seems to be doing the same thing…Subsequent online exploration, I find this forum, and exploring various posts, I discover that I can remove a panel to better access motor area, and looking down, I see a wire going to motor has burnt in two at the terminal. When I cleaned the connections earlier, I was working from underneath and only saw the two rear motor posts, not the front two. With this motor cover panel removed, it (obviously) opens up the view better and I can easily see & access the other front two terminal posts.. I replaced the burnt wire with new ( 2 hr drive to cart store) and put it back together and hit gas, she jumped forward-SUCCESS!... I button her all back up, hop on, and nothing…no solenoid noise, no movement-nothing. I tried putting original solenoid back on but that one wont even click. I now know that my earlier "repair" success after cleaning up the connections was probably the result of the burnt wire terminal getting jostled back near enough to the motor pole that some contact could be made making cart run again and appearing that the first repair efforts were successful. I hesitate to post this confession as it immediately labels me rather foolish and I wish I had explored my options deeper before changing solenoids and the fact that I missed the front motor posts (with the burnt off connector) deepens my embarrassment, but I hope that someone has an idea or two that may give me hope. I triple checked the new wire (just in case ) and it is verified good.

From the diagrams, I still am not sure if this is a DCS, or Non- DCS cart but I took off the cover on the left wheel well underneath the seat, beside the batteries (under this cover is the solenoid and a black box) and my black box behind the solenoid has four LARGE terminals on top whereas the diagrams in the stickies all seem to share that they have three large terminals on them with two small wire posts on the far left and this one definitely has 4 large with a 6 pin white connector (only 4 positions used) below and center of the four large terminals.

The black control box behind the solenoid reveals the following voltages.
Far left = 35.8 middle left = 35.8, middle right = negative 0.0, and far right shows 35.9 and there is no change on voltages regardless of whether gas pedal is pushed on not.

The small white connector that plugs in below and center of these 4 large posts shows left / RED = 0.5 and 2.2 when pedal is pushed…. Orange = negative 0.0-…Black = 0.0 and White = negative 0.0

Solenoid testing reveals that the battery pack reads 37.6 volts. There is NO reed switch at all where the battery charger plugs in, (I cant find any evidence anywhere that my reed switch has been bypassed, the charger input only has two large wires)… With my black test meter lead grounded to battery negative, the original solenoid reads 37.7 at both large posts, regardless of whether or not pedal is pressed. Small red post on solenoid reads 0.6 when in FWD, key on, and changes to 2.2 when pedal is depressed. Placing the test meter between both small solenoid posts shows 0.6 and changes to 2.2 when pedal is pressed, in FWD or REV, with key on (solenoid not clicking). My solenoid has small diode between the two small posts and the stripe faces left. There is a larger(diode?>) that runs between the two large solenoid posts and this layout matches the illustrations shared in the “Basic EZGO Golf Cart wiring and manuals” sticky, as does all of my other wiring so original wiring routing is preserved. The donor solenoid from my parts box didnt have diodes attatched but I put the two from my original on it during the swap. For the record, I cant remember where this donor solenoid originated but it is labelled 36V.

Under floor switch by gas pedal testing shows that with my test meter negative lead grounded to negative battery post, key on, and in both forward and reverse, the RED wire reads 0.5 and moves to 2.1 when gas pedal is pressed. The GREEN wire reads 32.3 and moves to 2.1 when accelerator is pushed. The WHITE wire in this area reads negative 0.0 and becomes 0.0 when pedal is pushed. The BLACK wire reads 0.0 both ways... In Neutral gear position, RED = 0.6, then 0.7 when gas pedal is pushed. GREEN = 0.2 then 0.7 with gas…WHITE = negative 0.0 & negative 0.0, and BLACK = 0.0 both ways…

Directional switch assembly voltages are 37.0 to all four of the big posts in FWD and 37.0 to all four big posts in REV….and stays the same regardless of whether or not gas pedal is depressed. The small switches show 37.7 to both posts on BOTH small switches in REV…Oddly enough, in FWD, this changes to 37.7 to both Blue and Red wire to right switch and 37.7 to the red wire on the left small switch and 0.0 to the orange wire @ the left small switch.

The Motor is a General Electric 36 volt 2 HP, has EZGO I.D. label attached and appears to be original to cart.Voltages at motor at all four posts reads 36.8 volts regardless of pedal activation or not.

I have removed both positive and negative wires @ battery pack as some readings appear alarming to my untrained mind and I don’t want to cause additional damages due to inexperience. I apologize in advance if I have provided unneeded or too much/too little info as I am striving to not waste too much of your valuable time and Ive tried to be concise enough to provide proper info to assist in helping me get her back running again,

Thank you !

[rabbitreborn]

Hopefully this should help. From what I am reading you are losing power on the solenoid activation circuit. your circuit is somewhat different as you have no reed switch, it sounds like they are pulling power straight from the batteries to themicro closest to the battery pack on the F&R switch. I would start checking for power at the blue wire on that micro and go forward from there to determine where you are losing power.

Txt solenoid activation
power starts on the white wire on the 36+ of the battery pack.
Power travels to the charger receptacle, goes through a reed switch inside the receptacle and comes out on the red 12 gauge red wire. ( check for power here, 1st!)
the red wire travels back through the loom to the forward and reverse switch where it attaches to a micro.
The other side of that micro has a blue wire attached that runs under the cart to the front and arrives at the keyswitch.
The keyswitch then transfers power to a green wire which returns to the area of the forward and reverse switch.
The power then goes through a 4 pin molex connector and travels to the "pedal box" (located under the floorboard of the car) where it goes through a micro and comes out on another red wire.
That red wire comes back up to the controller/f&r area where it once again goes through the 4 pin molex connector and continues on to the small post of the solenoid.


BTW, you have an early production Series cart, the extra large lug on the controller goes to the A2 post on the motor(actually it goes to the F&R but eventually makes it to the A2 post on the motor). This was done to allow "plug braking" which basically prevented you from rapidly switching the power flow through the motor from one direction to another. It has since been abandoned and any replacement controller you may purchase in the future will eliminate this post and you would simply eliminate the wire that was attached to that post.

[LOADER]

Thanks for providing help, I have a better outlook, now, with the assistance you provided and will check out the solenoid activation circuit.

Thanks again!

[LOADER]

Not getting power to the two small terminals on the solenoid....This may be (another) foolish question, but can I put a "jumper" wire between the green and red wire at the underfloor throttle box mini-switch without danger of frying something ?.. I get power up through the key switch, key switch checks out and is good, power all the way to green @ floor box, but no power exiting small switch red wire lead (goes back to soleniod exciter, correct ? ) making my untrained suspicion that maybe underfloor throttle micro switch = bad.... any thoughts on this ?

[scottyb]

Power in & no power out of a micro = a bad switch... Yes you can jumper it for a test only.... but likely you need a new one.

[rabbitreborn]

That Micro costs $10 or less...... there is absolutely no reason to not replace it. While you have the cover off the Pedal box assy, drill a couple of 1/4 inch holes in the bottom of the plastic to allow drainage in case of riding in wet locations.

[LOADER]

Think I will snag a spare or two while at cart store since they are so affordable. Looks like a bad area to collect dirt, dust, H2O, great idea to drain it !.. I bypassed switch with jumper (rear end off ground ) but still a no - go... Get battery pack voltage back to small red post on solenoid, yet no dice. Both solenoid large posts get batt pack voltage on this new solenoid. I replaced the diode and resister w/ the new solenoid and I still I get batt pack voltage to far left, center right and far right posts on my older 4 terminal passenger rear wheel well control box but center left reads 5 volts +/_...... Any ideas or areas to checkout further?

[scottyb]

It sounds like a bad controller.

[scottyb]

If you take a spare battery cable & connect it to the solenoid's 2 large posts ... will the cart run?

[LOADER]

Success !...Got her running again last night. The past few evenings I was growing discouraged and I kept hitting dead ends & various roadblocks but I kept coming back to the "TXT Solenoid activation" diagnostic / stickie...
that Rabbitreborn posted for me...Finally,, everything clicked and it all made sense, but in becoming clear, it exposed my anxiousness to get the thing back on the road and in doing so, I foolishly "overlooked" a few tidbits and that was the block. Final diagnoses was faulty microswitch in underfloor throttle ( sometimes it worked, sometimes not ) and it's hit or miss voltage readings. Problem number two was green wire from key switch. There is a inline soldierless spade terminal that mates to a matching female connector by F/R switch. I was taking readings from this CONNECTION (which always gave positives ) , but not on the wire leading away and this thing had a small area without insulation and the wire itself was broken, also giving intermittent positives as well !.. Thanks scottyb & rabittreborn for the help!