Cadillac cruise control is on but cant maintian the seed Why

[brian]

When driving with cruise control on i was driving at 100 for more the half n hour but then somehow the speed started going down

100-90-80 it was very gradual so i didnt notice so i accelerate and switch on the cruise control again and it was engaged but only for 10 min.

What should i do.

[james]

check the fuse relay if it is working.