curtis pmd troubleshoot help

bacord

I have a new to me golf cart it looks like a ez go maybe late 80's. When I bought it didn't run and was told it ran but the charger went bad so the batterys are shot. I bought a brand new set of batterys and a brand new charger and new Heavy Duty Solenoid . I turn on the key and push the acc petal and nothing, no clicks or anything. The throttle postion thing has 3 wires coming out, 2 to the controller (black and blue) and the third wire (green) goes to a small post on the Solenoid. The micro switch on "Throttle postion thing.????" works. It's a Curtis PMC mod#1204-017 275 amp 24-36 volt . I get 38.4 volts from key to neg on last battery. I get voltage on one side of key with key off and voltage on both side of the key switch when key is on so I guess that's ok. On the big solenoid I get 36.7 to neutral on the larger post with 2 4 ga wires, One going to A1 on motor and one to the bottom right connector on controller (see pic) and 38.4 on the other large post on solenoid going to POS on #1 battery. From the 2 wires (black and blue) that comes from the acc petal to the controller I start with about 750 ohms at rest and climbs as I press the petal up to about 4000 ohms then O/L at full throttle.I see Scottyb's Ezgo diagnostics I just need to to know if it's a ITS, DCS or what ever.These are old pics and I cleaned all connections one at a time. Is the black thing between the solenoid and F/R switch a back up alarm or what. If some one can point me in the right direction I think I can save her. THANKS . .

BGW

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rabbitreborn

That controller setup reminds me more of a Melex (which would look VERY similar to an E-Z-GO since Melex was a Polish made cart based on the E-Z-GO Marathon design)

That being said, The pic of the controller you posted makes me concerned... it appears that there is a gap in the sealant of the controller that could have allowed water/dirt inside the unit.

If your meter is going to O/L when doing the test on the pot box, that typically means the pot is going out of range which would make me suspect a bad pot.

Try jacking up the rear end and place your volt meter on the 2 small posts of the solenoid and then depress the accelerator pedal. you should get full battery voltage at that point, if not, we need to look at the activation circuit of the cart.

bacord

Thanks for the fast reply. With the back end jacked up and I press the acc I get 0 .01 volts between the 2 small post on solonoid. I don't want to pour a bunch of money just changing parts.The floor was rusted out so I put in a wood floor so the pedal needs to be adjusted. The cart is in really good shape other wise.

bacord

I tested the voltage at the 2 small terms on solonoid in F, N, and R and nothing. From neut on battery #6 to all 4 post on F/R switch is 36.7, and battery pack is 38.4. I did find a bad micro switch on F/R switch for forward but still no reverse or anything.

rabbitreborn

The forward Micro is actually a power micro. For a temporary test, bypass that micro. The easiest way would be to jump power straight from the main battery positive to the small post of the solenoid that has the red wires on it. once you do that, press down the accelerator pedal and see if you get tire spin. Make sure the rear is supported on jackstands before doing this of course.

bacord

WOW a dead short without giving any pedal. A wire jumper from battery + to little post on solonoid and instant short.

bacord

With a little searching I found out it's a 412 and found this wireing diagram for it but it don't show the throttle part, or much on F/R switch

rabbitreborn

I have a feeling the problem is that controller. trace the 2 small red wires on the solenoid. 1 should go to the micro on the FNR, the other should go to the controller. If I am right and dirt/water has been entering that controller, then that would cause a dead short.

bacord

One of the red wires goes to the controller and the other goes to the micro on the box that the acc petal connects to. I get 36.8 volts from both small post to battery #6 + and 0 from same post to neg. Thanks for putting up with so many questions and bearing with me. I think the whole thing needs to be rewired I just need a wiring Dia. THANKS SO MUCH

rabbitreborn

ok, here is the activation circuit on that cart (wire colors could be anything so I am just going to tell you how they route):

from D/S front inside battery to the keyswitch.
from Keyswitch to the micro on the F&R.
From F&R micro to a micro on the Pot Box
From PotBox Micro to the solenoid.
From the solenoid to the controller.

On the ground side, it usually jumps from the B- on the controller to the solenoid.

that being said......
Key on, Cart in gear, pedal depressed, you should see full battery pack voltage between the 2 small posts of the solenoid. If you are seeing that and the solenoid doesn't click, you have a bad solenoid. If you are not seeing that, you have to retrace the circuit until you find where you are losing power at.

If the solenoid DOES click, and the wheels still do not turn, you have to check voltage between the main pack negative and each of the large posts of the solenoid. If they match and the wheels still don't turn, then we can test further. If they Don't match, then you have a bad solenoid.

If they do Match, then we can run tests further......