I am having a bit of trouble diagnosing what's wrong with the cruise control on my EL, I have followed the troubleshooting guide on here, and the conclusion I have come to is that the ON switch is not working. I also have no HORN operation. I am suspecting these 2 are related. I have tried another ON switch that was working in another car (it doesn't work) and I have replaced the clock spring (still doesn't work) What's left? will the horn relay cause similar issues?

Gab

I was going to say clock spring, but since that has been rectified I suggest you look at fuses/relays and brake lights and brake light switch. Do you have a clutch switch as well?

Also have you checked the light bulb in the cluster to make sure it hasn't blown?