my 99 TL is making a rapid clicking noise when I attempt to start the vehicle. All lights (headlights, cabin and instrument) appear to be fine but fade once I turn the ignition so I believe the battery is fine (tried jumping it just in case, but clicking sound remained). The rapid clicking noise is the only response I get when I turn the key.

It is my fiances' vehicle and we are attempting to sale it. We have an interested party, but need to get it started. Car has sat idly for about a month. Previously the car would start sometimes fine and other times she would need to instantly give it gas in order for vehicle to start. From doing some perusing on here tonight, it appears this might be a common issues with the 99 TL...

 

Sounds like a dead battery, take the battery out and have it load tested at a shop or battery store.

 

As per the post above, you may need a new battery, go get yours tested (this is free in almost every automotive store).

 

when a TL sits for a month it can kill the battery,,the clock and alarm will wear it all the way down
When its that low on voltage, it wont process a jump start thru it,,
example--hooked up jumper cables and immediatly tried to start..without letting some juice get pushed over to the dead unit for 5-10 minutes then try

use home battery charger, or remove batt and take to parts store-
they do a `quick charge` for an hour then load test it- simulating a starting load and the batteries abilty to handle and recover from that
It passes or it needs a new batt

Assuming batt, once installed- drive it 30-45 minutes without extra load-(headlights, fan on high, seat heat, leave off) so the alternator can get the new battery to `fully charged- to the cars liking`
then have the charging system tested at parts store--thats free too
Make sure all is well now

if the battery is 3-4 years old you can expect failure anytime

 

money saving tip: ask for a `blem` (blemished) battery if available
thats cosmetic damage to the case,,a broken hold down tab we dont use etc
I got a 90$ unit at Batteries Plus for $45 that way,,it works perfect

I say to drive it after install because MOST places have the batts sitting for weeks or months on the shelf-slowly draining their own power

Batteries Plus was unique in having a `Battery Tender` machine charger system- every batt off the truck in weekly shipments gets put on the charger so its full full for the customer

 

if its not the battery then you are having starter issues.

Also to note, starting a car with a low battery will eventually kill the starter.

good luck and post back with your results.