sequential turn signal playing up on 68

on my 68 tbird i have noticed that the turn signals have started playing up a little. rather than going one two three they go one & two at the same time and then three the first two lights or the three light up first at the same time . cant see any random wires loose etc so do you think the unit is starting to die???

Cougars unlimited has a small troubleshooting guide on their website.

thanks that helped us - then we found a relay in the back hidden right near the rear seat which was rusty so we fixed that and they work really well now.