Chevrolet Repair: rapid clicking question, jumper cables, starter solenoid

Question
My wife has a 99 suburban and started getting this rapid clicking sound when she starts the car--followed by what appears to be the starter trying to start the car then followed by the rapid clicking sound again..I used my jumper cables in an attempt get enough juice to first raise the electric driverside window and then tried to start the car again--to my surprise the engine started without any rapid clicking sound..My wife also says that this only happens on the first ignition start of the day--the rest of the day no problem...The first ignition start is usually at 9am pacific not cold about 80 degrees...Can you explain what appears to be at fault...Thank you much..


Answer
Most of time a rapid clicking is the starter solenoid trying to engage with a undercharged battery.

Have the battery tested...if it's more than 3 or 4 years old just replace it.

Remove battery terminals and check for corrosion. - Repair as necessary, new terminals or cables (this has been a problem in the past, battery acid leaking causing corrosion).

If both of the above items are ok, have the charging system tested.

If all 3 of the above items test ok then something is causing the battery to drain down while the vehicle sits overnight. It could be something as simple as a lamp left on or similar. You'll have to have the system tested for an excessive parasitic drain. If you have rear heater/ac the rear fan relays have been known to stay stuck on causing the battery to drain down. It possibly can be that.

Hope this helps