Hi all.

got a new battery. Did well for 5k miles. Now it doesn’t start but there were telltale signs prior to this so I’m not shocked.

I need to get the battery tested. Assuming it works, what else could it be? Do I need to clear Earth cables? If so, how?

1. my car is lpg converted.
2. The car would attempt to turn over, but would stop E.g I’d hear one click and then silence. I’d have to turn the key two or three times before the car would start.
3. The car is completely dead as if the battery has died. It revives itself by displaying the mileage on the dash, but if I attempt to start the car, flat it goes again.

What could it be?

 

If you have a multi-meter, I would do just a cursory check of the battery to see what voltage it's giving out.

Attached is a diagram of the body ground locations as well as the main power distribution. Considering the car goes completely, lights out, dead, I would be suspect of big picture things:
Check the positive and ground leads on the battery, make sure there's good contact.
Follow the positive lead to the high power protection module with all the fusible links, Make sure there's good contact there.
Follow the ground lead to it's connection on the body. Verify that it's clean and solid.
You can try measuring voltage drop with the ignition on and resistance across these areas as well.

If you can get the car cranking for a bit, see if you can feel around for any hot connections around the battery area (Hot = high resistance = bad connection).

https://www.mediafire.com/file/j4irvgbrd4f6dk4
Here's a link to an electrical troubleshooting guide with more information.



Body Grounds

Positive power distribution

 

I would suspect an electric issue, like:

a.) parasitic voltage drain: that happens, if somewhere in your car something consumes power when the car is parked, even though it should not. Also, you did not mention, how long the car was parked, before you have that issue - I'd say, if it is more than 2 weeks, this could possibly be "normal" for a Jag, as they use quite a bit of power, when parked.

b.) a broken alternator would do that: Obviously, it does not matter, that your battery is new, if it does not or not properly get recharged.

c.) a new, but faulty battery could also be the reason.

You definitely need a multimeter (they are cheap) to investigate further, and you need a battery charger anyway - if you have a Jag, you need a battery charger: A CTEC, 7A or 10A.

If it turns over only 1 click, it cannot start, regardless, if you have switched to 95/98 octane or LPG.

 

Does the car have a volt meter on the instrument cluster ?

 

Tachometer, speedometer, gas gauge and temperature only...

Not that I would trust an instrument cluster volt meter, oil pressure gauge or the temperature gauge to be particularly accurate in any case (as an indicator of "not quite normal" perhaps but no more than that and the idiot lights probably do just as good a job of that).

PS apologies for the dust in the photo...

 

"One click and silence" surely sounds like a "not enough juice" issue.
If a voltmeter gives you more than 12 volts across the terminals of
the battery, then I would first check to make certain your ground is
good. Terminal connections and starter checks from there.

 

@ Randy: Yes (ground-issue, if battery is fine).
@ thread starter (with the many letters): It all starts with a multimeter, as I wrote above... - did you see my post?

 

Just to echo the great replies you have already received, the most common cause of your symptoms is low battery voltage while cranking or attempting to crank. The second most common cause is high resistance in the battery power and ground connections throughout the car between the battery in the trunk and the ECM, alternator and starter in the engine bay, causing the voltage while cranking to sag low. If the voltage sags much below 11 volts, the ECM will not trigger the ignition to fire.

Good regular maintenance on Jaguars is to disconnect the battery, then work your way from the trunk to the engine bay, cleaning every battery power connection and ground point you can locate and access. Critical ones include the battery cable terminals, the battery negative cable ground points at the body, all the megafuses, studs and ring terminals at the high power protection module, the connections at the alternator and starter, and the engine ground strap (both ends). If your engine ground strap appears corroded (green), add a second ground strap between a lower transmission bell housing bolt and the body (clean the ground strap connection at the body). The bolt where the original ground strap attaches to the bell housing cannot be removed with the catalytic converter in place, which is why I just add a second ground strap. Most auto parts stores carry a suitable short cable with eyelet/ring terminals on both ends.

To clean the power and ground connections, I remove the nut or bolt that secures the cable terminal, remove any star washers, and thoroughly clean the threaded stud, washers, nut, and all cable eyelet/ring terminals on both sides with a small brass-bristle brush and electronic contact cleaner (I use CRC brand but others are available). Reassemble each connection and snug the nut - tight but not too tight - some stud threads can be damaged or the entire stud snapped off the body if overtightened.

You can take your battery to an auto parts store to have it load tested, but a good independent shop may have a more sophisticated battery analyzer that can better assess the battery's actual capacity versus its rating.

See Rob's (avt007) electrical troubleshooting guide that asdf provided the link for - it is a great reference.

Cheers,

Don