if the flasher unit fails, then it will not flash at all. The reason they are flashing too fast is because the bulbs are not drawing enough current, you will notice that if you see a car with a fast flashing indicator then one of the bulbs will have blown, so it isnt drawing as much current, hence the fast flashing.

What should the chaser have as standard? Does it have side repeaters? If not, remove them and take them out of the equation for now. The front and rear indicators should have 21 watt bulbs as standard, so they pull enough current to make the relay flash at the correct speed. Make sure that they both have these bulbs.

When thats done let us know what happens and we can go from there