I have a 1998 chevrolet suburban with a clicking noise under the dash and the horn beeps at same time and rate as clicking noise. Replaced turn flasher but no joy. Slowly moved turn signal up no joy. Slowly moved turn signal down no clicking noise but horn continues to beep. When driving clicking continues and horn stops. Regardless if parked or driving the exterior lights work correct and don't do anything abnormal.

 

Hi dgmm4,

Welcome to the Chevy Forums.

I moved this to the Suburban Section, and posted to bring it to the top of the field.
Hopefully you may get an answer here.

 

maybe the horn relay?

 

Replaced horn relay, no joy. Looking for more suggestions.

 

The problem may be a defective connection in one of the outputs from the BCM (Body Control Module) It is located behind the knee bolster and has 3 connectors on the front and on on the rear. There's relay within that activates the horn. It's used for the security alerts, lock snd unlock horn beeps. That clicking you hear most likely is that relay opening and closing thus activating the horn relay located in the box under the hood. Now, why is it clicking on and off. It may be an issue with the security circuit itself.
Now before you operate on your patient, try this:
Open the remote security probably on your key chain by slipping a dime near the ring. When it's opened REMOVE the battery. (assuming the door is unlocked) Then start the car and see what happens. If the problem goes away it's the remote key lock. Probably a short on the little printed card inside. Let us know if that solves the issue. Also if you have 2 remote keys try the other while the battery is out of the first one..