Possilbe MCOR Failure on 2005 48V Precedent Club Car

[jhannaman]

I think my MCOR is not working correctly. The cart will not go in forward at all and sometimes it goes in reverse for a short distance. My reverse buzzer does work. I followed the troubleshooting guide for my electrical system and tested solenoid for continuity and the activating coil...OK.

MCOR Voltage: testing the wires at the 3 pinned plug into the MCOR I did a voltage test on the purple wire to the positive battery and was OK at 48V. Also,the white/black wire to the negative battery, and I got 1.040V vs. the required 4.65V. Also I tested the yellow wire to the negative battery and got reading of 0.03 to 1.030 as I pressed the foot pedal vs. the required 0.32 to 4.65 Volts.

MCOR Resistance: At the same 3 pinned plug to the MCOR, I tested the yellow wire to the purple wire and read 2.25k ohms vs. the required 1k ohms. I Slowly pressed foot pedal and read between 2.25k ohms and 7.60k ohms vs. the required 5.67k to 7.43k ohms. I tested the Yellow wire to the white/black wire and read 7.60k ohms vs. the required 5.67k-7.43k ohms. I then slowly depressed the accelerator pedal and it ranged from 7.6k ohms to 1k ohms

Are these readings an indication that the MCOR should be replaced? Many thanks for your kind assistance.

[Stevegrmich]

First, welcome to BGW . . .

Second, you have tested and noted that your MCOR readings are out of spec with the service manual . . . note last sentence of that section of the service manual:

If the MCOR does not operate as described, replace the MCOR.

. . .

[jhannaman]

I thought so, but appreciate your reassurance. Many thanks and Happy Holidays!

[BRS]

I am no expert (disclaimer), but if your solenoid is engaging then your mcor is not bad. I' have a similar problem with my precedent and at this point believe it to be the controller. My half cent....good luck!

[Rockstar007]

Any updates on your problem?
I am expercing similar symptoms with my '04 P
I have not performed the testing that you have simply because it sounds like my issue may be less frequent than yours.(mine is an intermittent problem) and I can hear my solenoid click.
I am in agreement with BRS, the solenoid coil being energized should rule out the MCOR. Should this be a fairly accurate assumption?
My new solenoid is on its way. After 9 years I am sure that it cant hurt to replace the old one anyway.

[sunoco]

The mcor can engage the solenoid and still not send the proper response to the controller. I just replaced one that worked fine until it got to about 95% throttle and would cut back. Dont rule out the mcor just because the solenoid activates

[BRS]

Originally Posted by sunoco

The mcor can engage the solenoid and still not send the proper response to the controller. I just replaced one that worked fine until it got to about 95% throttle and would cut back. Dont rule out the mcor just because the solenoid activates

You had to go and confuse me didn't you....
I haven't pulled the trigger on a new controller yet and my solenoid sounds healthy, so back to mcor or controller? This may be a dumb statement but continuity could still be evident and not rule out a thing....yes?

[DJBlade]

Picture the MCOR as a wiper blade on your windshield. Down is off, and a full wipe is wide open. Just because the wiper looks good, wipes from left to right completely doesn't mean it is a good wiper. It can do all this and vibrate across the windshield, have drop out spots where it skips, streak the windshield.....needs to be replaced. The MCOR is similar. Just because it activates the cart when you push the pedal, doesn't mean it won't have drops or spikes in signals to the controller (ie a jumpy windshield wiper blade). Most problems as you describe are MCOR related. I work on these daily....

[BRS]

Originally Posted by sunoco

The mcor can engage the solenoid and still not send the proper response to the controller. I just replaced one that worked fine until it got to about 95% throttle and would cut back. Dont rule out the mcor just because the solenoid activates

Originally Posted by DJBlade

Picture the MCOR as a wiper blade on your windshield. Down is off, and a full wipe is wide open. Just because the wiper looks good, wipes from left to right completely doesn't mean it is a good wiper. It can do all this and vibrate across the windshield, have drop out spots where it skips, streak the windshield.....needs to be replaced. The MCOR is similar. Just because it activates the cart when you push the pedal, doesn't mean it won't have drops or spikes in signals to the controller (ie a jumpy windshield wiper blade). Most problems as you describe are MCOR related. I work on these daily....

Don't mean to hijack...didn't get much response on my other post. My precedent is not intermittent, it does not move at all at this point. Cart is fully charged holding 52 volts, solenoid pops and no movement at this point. I know on my ds I get shuttering then nothing when the controller goes into thermal shutdown...I'm thinking the controller is still the culprit?

[smokey tennis shoe]

my precedent was having similar issues. I replaced the forward/reverse switch, and fixed everything.

My experience with mcors, have been that they will cutout and back in on you, but not completely stop.

When I was thinking my mcor was bad, was when my cart sometimes would not go in forward, but didn't seem to have a problem in reverse.

I posted here on the forum. and David immediately told me, that the mcor was not the problem, try the f/r switch . I pulled the switch out, unhooked the 3 wires, then clipped the 2 wires together, and it went in forward without a problem.

I changed my switch for about 38.00, and all is well.