Yesterday my 2002 XK8 would not turn over and start, just a click noise. Using my boost pack the car started easily. I had driven the car 2 days before with no issues.

After starting the car I drove the car about 50 kilometers (30 miles). I turned the car off and then it would not turn over and I had to use the boost pack.

Once I was at home I once again tried to start the car, no luck but this time the car started a continuous clicking noise and the lights on the oil pressure and ammeter gauges started flashing. Also the light beside the park area of the shifter. I disconnected the battery to stop the clicking.

Today I reconnected the battery and the car started first turn.

Any insights or suggestions are welcome.

 

Clean you battery and cable terminals with a wire brush designed for the job. Also after doing so, check the battery voltage after a trip, if not up to 12.5V at least then check it while running, should be in the 13.6V or more, if not a alternator is in your future.

 

Battery age ?

has the battery been tested in a load tester (not just a voltmeter) ?

are you keeping the battery on a battery tender when the car is not being driven (even just overnight) ? That actually does make a difference with these voltage-sensitive old cars.

Z

 

I tested the battery with my battery tester. Showed 12.7 volts and a good battery. Not really sure how much I trust these inexpensive battery testers. I will try cleaning the posts and terminals as that appears to be the only thing that seems to fit what happened.

Thanks to all for our suggestions.

 

Not saying one size fits all, however, my own car experienced many electrical anomalies including not starting before I started using a battery tender. Since then, over a period of nearly 5 years and well over 60,000 miles the car has been trouble free. Maybe a coincidence, maybe not.

Z

PS : FWIW, a volt meter is a valuable tool, but no substitute for a battery load tester.

From Amazon:

Schumacher BT-100 Battery Load Tester and Voltmeter - 100 Amp,Black


https://a.co/d/iCXM26U

 

A proper load test on our 110AH batteries would be to load it to 330A for 10 seconds and if it drops below 9.6v its failed.. How many home testers can do that ?
Those toast rack testers pull at max 100A.
Using a tender does not give your battery infinite life .If the magic eye will not show green change it ( its a built in hydrometer) even then the eye is only in one cell. If it will not go green the sulphate is in the plates not the acid and the battery is useless.
For 20 years I worked with one of the UK best battery experts having run a battery factory in Yugoslavia after the war ...Miserable old *******