05' CC Precedent MOCOR replacement

[Keith]

Gaminde,
I'm back home from our lake place where I keep my golf cart and wanted to let you konw that I installed the new MCOR and my cart runs like a new one again. I have the old MCOR and I couldn't resist cutting it open to see what made it tick. From what I discovered is that the OEM mocors are epoxy sealed and there is no way anyone is going to just open them up. It also appears that the only way anyone can remove the circuit board is that you would first remove the screws then melt the solder and lift the board from the pin plug connections. I can continue, or if you still want me to send it to you, let me know. Keith

[gaminde]

Hell yea keep going looks like they make there own pots. Lots more pictures please

[gaminde]

How much are new units

[relentless]

The cheapest I've seen are around $120. I think list is about twice that much.

I'm still driving mine around with the two pin connector jumpered and bypassing the mcor. It runs ok for a bit then suddenly will drop out the solenoid, but moving the pedal re-engages the solenoid and the car takes off again.

I thought I saw an exploded view of the mcor once that had a series of contact plates and resistors that determine the output voltage to the motor. Keith, did you see any signs of burned parts or smell burned silicon when you opened it up?

[Keith]

O.K., I'll keep disscecting this thing and take lots of pictures. There were no signs of corrosion or bunt parts. That's what I was hoping to find.

Ya, I paid $120.00 plus $8.95 shipping for my new one.

[Keith]

Here are some additional pictures with the board removed.
pic-2: static cling of sawing dust. If you look closely you can see the end of the spring for the pot pivot arm.
pic-4: pot track cleaned.
pic-5: ohm tested limited switch again (original failure) and it failed again.
pic-6: shows the two copper rivets that hold the limit switch together. I drilled them out so that I could seperate the halfs.
pic-7: the contact points are suppose to pivet in unison even though they are mounted indepently. I found that one of them was hanging up and not making contact.

After playing with it for a while I noticed that they were back in unison again so I reassembled the limit switch and ohm tested it again. After at least twenty cycles it passed every time.

I hope this may be helpful to you guys for future trouble shooting of the MCOR in or CC's.

[gaminde]

Keith nice job I now have a very good idea of how these things work and the type of problems that will be encountered. Thanks for all the work.

[relentless]

I found my test procedure for the MCOR but not the exploded view picture.

MCOR Test

1. Lift rear wheels. Position jack stands under the frame cross member between the spring mount and side stringer, just forward of each rear wheel.
2. Note – The key switch should be placed in the OFF position and left in the OFF position for the duration of this test.
3. With the batteries connected, place the Tow/Run switch in RUN. Using a multimeter set to 200VDS, place red probe on battery no. 1 positive post and place black probe on the purple/white wire at a point close to the 3-pin connector at the MCOR. The reading should be approximately 45-50 volts (full battery voltage).
4. If reading zero volts, check the purple/white wire continuity from the 3-pin connector at the MCOR to the 16-pin connector. If all the continuity readings are correct and the connectors are wired correctly, replace the SPEED CONTROLLER.
5. With the multimeter set to 20 VDC place the black probe on battery no. 4 negative post and the red probe With insulation piercing probe) on the white wire at a point close to the 3-pin connector at the MCOR. The reading should be approximately 4.65 volts.
6. If reading is zero VDC, check the white wire continuity from the 3-pin connector at the MCOR to the 16-pin connector at the speed controller. Check terminal positions in 3-pin connector at the MCOR and the 16-pin connector. If all of the continuity readings are correct and the connectors are wired correctly, replace the SPEED CONTROLLER.
7. With the multimeter set to 20 VDC, place the black probe on battery no. 4 negative post and red probe with insulation piercing probe on the no. 18 yellow wire at a point close to 3-pin connector at the MCOR. The reading should be approximately 0.32 volts with the pedal up. Slowly press the accelerator pedal and note the readings on the multimeter. As the pedal is pressed, the reading should increase until it reaches 4.65 V when the pedal is fully pressed.
8. If the reading is not approximately 4.60 Volts with the pedal fully pressed, the vehicle will not operate at rated top speed. Check the MCOR resistance.
a. Disconnect the battery cables as instructed. SEE WARNING “To avoid unintentially starting…” in General Warning, Section 1, Page 1-1.
b. Disconnect the 16-pin connector at the speed controller.
c. Set multimeter to 20k ohms. Connect the red probe of the meter to the yellow wire at the MCOR 3-pin connector with an insulation piercing probe. Connect black probe to the purple/white wire with an insulation piercing probe.
d. With the accelerator pedal fully up, the meter should read approximately 1k ohms.
e. Slowly press the accelerator pedal while monitoring the meter. The resistance should rise as the pedal is pressed. When the pedal is all the way to the floor, the meter should indicate between 5.67k ohms and 7.43k ohms.
f. Using a meter set for 20k ohms, connect toe red probe of the meter to the yellow wire at the MCOR 3-pin connector with an insulation piercing probe. Connect black probe to the white wire with an insulation piercing probe.
g. With the accelerator pedal fully up, the meter should indicate between 5.67k ohms and 7.43k ohms.
h. Slowly press the accelerator pedal while monitoring the meter. The resistance should drop as the pedal is depressed. When the pedal is all the way to the floor, the meter should indicate approximately 1k ohms.
i. If the MCOR does not operate as described, replace the MCOR.