turn signal doesn't work fine

When I press the turn signal to right or left (fully), nothing happen. No flash.

But when I hold it (not pressed fully), it flashes, but very very slow.

When I use the 4 way flasher, it work at normal speed.

All the bulb light up.

What can cause this problem?

I thought that it was the multi function switch, but it can't explain the low speed when I hold it. It can be the flasher unit?

Post the year of the car.

It's a 95 cutlass supreme.

Repace the signal switch, common problem on these cars.

Ditto -- I have a 92 olds cutlass supreme and I've replaced the turn signal switch twice. I think it's about $110-125.