If you are having issues with your Touchpad / Trackpad not working or not working properly, try installing the following with Synaptic: xserver-xorg-input-synaptic.
This is the older X.Org Server Touchpad Driver and will supersede the newer one once installed. Reboot after install.
I found this solution over on a Manjaro Help Forum. The Touchpad on my old Dell laptop would not side-scroll and would act erratic like I had a "Drunk Finger". After an install and reboot, Touchpad worked as it should.
