Inside An MCOR 01-04 DS

[Marshred]

I was trouble shooting my CC DS today and found the MCOR to be the problem. After much research, I see that this is a problem part on these carts. I figured being the machinist I am, I'd take this thing apart to see if it might be repairable... It can be done. I am going to get a used one but try to fix this one to have as a spare.

[Volt_Ampere]

What was wrong with it? It looks like it's very simple - a pot and a microswitch.

[Marshred]

The micro switch is bad. I am sitting here playing with it and an ohm meter. It is not making up correctly. It has 4 terminals. It uses the terminals that are "NC" normally closed. When the pedal is up the button on the switch is pushed so you have an OPEN circuit. When you depress the pedal, it releases the button and CLOSES the circuit. The "NO" normally open terminals are not used. It is showing a good bit of resistance instead of closing.

[Marshred]

Switch is:
LICON #11-304
Part is around $25.00.

Here is a little issue. Switch is only rated for 28 VDC. Does CC know that? That might be why these MCORs don't last...

[Marshred]

To open this up without breaking it....
I used a Rockwell Sonic cutting tool. I installed the thinnest curved blade. I put the MCOR in a wood vice so that when the blade was resting on the vice, it would cut just below the glued seam. Be careful cutting around the curved portion as you don't want to cut into the POT shaft. There is a glued pin on each side of the shaft, so be sure to cut deep enough to cut them but not the shaft!!! Carefully pop apart!
The contact pins must be desoldered from the PCB in order to lift it out. You can also desolder the switch posts at this time also. Lift the PCB out and unscrew the switch from the PCB.
It has some sort of dielectric grease on the wiper and PCB surface, so it will need to be cleaned off and recoated after changing the switch.
The switch I ordered should be here the middle of next week. I will post pics of the repaired MCOR.
Switch with shipping: $35

[sunoco]

You may be the first person to try this. I hope it works out

[RPatten]

I am curious how it is going to be sealed back.

[scottyb]

Silicone and zip ties or 2 part epoxy should close it. You want to seal water out.

[simple man]

I'm curious as to the resistance values of the pot. Seems like this would also be pretty easy to obtain from an electronics supplier!

[Marshred]

Well, the POT looked great! A little dielectric grease on the carbon surface will fix it up. The main thing to watch for when putting this back together will be the fact that the saw Kerf is about 1/16 inch. This will tighten up the end play of the pot shaft when I put the lid back on. I can use some shim material if needed and RTV SEALANT between the lid and box. There you have it!
{{{warning}}} I would not remove the pot shaft. It has a pretty heavy return spring that would not be fun to put back into place.