2000 xk8 won't start. The lights go on, but when turning the key, I hear a quick "snap" and then nothing. .

 

Remove the battery and have it checked for free at your local Autozone or Advance Auto Parts.

 

Battery alright. Lights, etc. are all working. When turning key, there is a "snap" sound, then clicking. The engine does not even try to turn over. Just the loud snap, a couple of clicking sounds. Does anyone have another suggestion, please?

 

Sounds like a electrical problem with either on the starter solenoid or the starter motor itself. You might want to be careful; if it is an electrical problem, that could be a lot of amperage to deal with.

 

Just because the lights turn on does not mean the battery can supply sufficient current to start the car. Have the battery checked...it is free.

 

Assuming the battery is ok (again, some batteries will light up the instrument panel, but not crank the motor).....And before you go to the starter solenoid my goto list would read (from easiest to hardest):

1) Check starter solenoid fuse. On a '97, it is in the passenger side (US model) Engine Management fuse box in the engine bay. Consult your owner's manual for location.

2) Swap the starter relay with a less critical relay. (The relay is different from the solenoid.) See Page 21....http://www.jagrepair.com/images/Auto.../jagxk2000.pdf

Or take a chance on locating the relay...the starter relay is the third relay down from the windshield (little brown box) in the engine bay, passenger side. Swap it with the second down - which is the windshield heater or some such. If the engine cranks, replace the bad relay.

3) Disconnect the battery......DANGER...DANGER WILL ROBINSON...DANGER Mommacat...Could be lots of spark, fire, bad stuff if you don't disconnect the battery and/or you cross wires. Proceed at own risk or have a trained technician do this!!!!!! See WARNING from max224 above !!!

In the trunk, disconnect the battery. Use a ohm meter and test the (MASSIVE 250 AMP) fuses in the High Power Protection module, located in the trunk, for continuity. If fuses are open, the car won't crank and/or spark.

4) If 1-3 doesn't work, and the battery is good, and the connections to the battery and Power Protection module are good, time to get under the car and look at the connection to the starter solenoid...and you might end up with requiring a starter replacement. Again, high Amperages are involved. Proceed with caution / Use services of a trained technician.

Note: I have only done steps 1-3 successfully. Never replaced a starter.

 

After everything up above this post, jack the car up, support it with jack stands and block the rear wheels. Crawl under the car and inspect the connections at the starter. There's a post on here somewhere about an XK8 with the same symptoms. The guy found a corroded/disconnected wire at his starter. He fixed it and it fired right up.

 

The ground strap goes to the transmission. Check that connection as well.

While you are checking the big fuses in the trunk, make sure the ground straps there are good as well.

A big snap by itself could certainly mean a grounding problem. A snap followed by some fast clicking usually means solenoid. On these cars, they are one unit so a starter would be in your future. The starters are only held on by two bolts, but one of those is a real bear to get to. Car must be up off the ground and you will need several extensions and elbow/wobble sockets to reach it. However, any decent mechanic can swap this out for you.