Hi all i have a mk5 1.3 escort and the heater has stoped working

but this is what i have checked i have checked the switch in the dash and it is reading 10.55 volts the main fuse box is reading 11/12 volts and the fuse has not blown, the main plug on top of the heater blower is reading 5/6 volts is this to low and if it is what is caseing it and how can i put it right??

i have also ran a test wire to the heater blower and it works fine on all three speeds so i know its not the blower and the horn has also gone very weak it hardly makes a noise could this be a bad earth mybe any help with this will be great

as i have hit a wall and it is driving me mad many thanks shaw109