my dad has a 03 1.8 focus. it had a problem where it would cut out at junctions so i did some research and replaced the clocks with a brand new set from my local ford dealer. fitted them and it doesn't cut out anymore which i good

but apparently now, if you accelerate quickly form a junction the speedo doesn't work until you stop and pull off again.

also (apparently) the radio goes quieter until you stop and start off again, and if youve got the lights on at night they go dim until you stop and start off again like theres a voltage drop or something

can anyone shed some light on this strange problem for me?