Problem starting

Depending on the year, make, model and engine there may be one or two solenoids and there may be other relays involved in the starting process (Will do the "other relays" later)

For example.. On a car my daughter once owned there was a recall.. Seems the starter solenoid pulled enough current to set the ignition switch on fire. So they put in what is called a "Pilot Relay" (A smaller relay that keys a much larger relay (Solenoid) that causes something to work) Some vehicles are designed that way from the drawing board.

It may be the pilot relay you are hearing, but if it's not making contact.

Page 2.

The "other" Epically in a motor home you might have relays for several devices on the ACCESSORY board, and there may even be an automatic "Disconnect" Solenoid all of which click when you start the ride.

That said: Knowing how to "Work around" a failure.. VERY IMPORTANT, and it appears.. You know.

Sounds like a bad connection to me. Check the tightness of all nuts on all battery cables...including the cable to the solenoid. We had this problem when we were on our Alaskan trip...took two days to determine that the nut on the cable connection to the starter was very loose. Tightened it up, and never a problem since.

Ron

The starter solenoid relay probably is mounted away from the starter on the frame.
I had to replace mine for the same reason.

Do you have a handheld meter?

The clicks you hear are probably the starter solenoid relay opening and closing. This can happen from a dirty/failing solenoid relay or lack of enough power to keep the relay closed. First step would be to measure battery voltage and check connections to make sure everything is clean and sound. If the battery is measurably good, the relay has failed and a new one is the remedy. A two post solenoid is still under $10, AFAIK.