So I got the Cateye CC-MC100W Micro Wireless installed but I won't get a reading. Any advice please.

Are both batteries good? Is the sender "pointed at" the display head. Is the sender's pick up aligned with and close enough to the wheel magnet? Did you read the Cat-eye instruction sheet and follow their recommendations?

Definitely check the 2 diff batteries. 1 is in the display unit and 1 is in the measuring unit on the fork. The zeroing point is marked on the bottom and you can only see it if you look through the spokes. The distance for the signal from the 2 devices isn't that far so make sure you have it close enough. Mine is set up half way on the fork and it works ok. Same goes for the magnet and the device on the fork. The instructions are kinda complicated but one thing I noticed that I overlooked was the button on the bottom of the unit, it's black and quite flat so you might have missed it and that might be used to set it up. I never had to set mine up, had the LBS do it : ).

Keep adjusting the distance and angle between the sensor and the magnet. You'll get it. I have it down to a first-try/everytime dance. It's easy after your first struggle. Measure the distance carefully.

I will look at the setup today try to move the sensor closer. The batteries are all in. It did not come with any instructions as I bought it used but I tried getting them online but I dont see the instructions.

Look here:

https://www.cateye.com/sites/cateye/u...C100Wv2ENG.pdf

good chance that the magnet and the sensor are too far apart

Or too close together. Really.

I just bought one of these and installed it yesterday. Mine worked on the first try, but as the instructions state, the sensor and the part that attaches to the fork leg have to pass within 5mm of each other when the wheel spins. Experiment with moving the sensor up and down the leg a bit, or you can loosen the nut at the top of it to angle the sensor toward the wheel more.

You might also check for interferance from outside sources. I have a CateEye Strada Double Wireless which won't work when its near a television that happens to be on.

When installing a wireless computer the first thing that I do is to install the wheel magnet and sensor. Locate them as high on the fork as you can. Then I hold the head unit close to the sensor and spin the front wheel to be sure that I get an MPH reading. Once I'm sure the computer is working I spin the wheel again and hold the head unit various places on the handlebar and stem, making sure that it works before mounting the head unit on the handlebar.

Wireless computers have a limited range and they also seem to be somewhat line-of-sight. Sometimes if the fork blade or something gets in the way they aren't able to pick up the signal.