Jaguar Repair: Series 3 XJ6 headliner, etc..., deep cycle battery, starter solenoid

Question
QUESTION: Howard,

Thanks for the headliner tip. I imagine that is to say the sunroof needs to come out again to do the sunroof section, correct? I have low confidence in my ability to pull this off. I can rebuild engines and replace and repair mechanical bits, but I generally have proven myself to be all thumbs with paint/body/interior work, so I'll likely still hire that out.

Now, I have read much of your advise to others regarding the use of a deep cycle battery on this vehicle, and always meant to ask if this is a design flaw, as in is this factory recommendation, or something you figured out along the way? Or, do these cars "develop" a need for such cranking power?

Mine sometimes only clicks when I turn the key, then on the next attempt, I may get a crank, but no start, then maybe a couple of subsequent attempts will only produce a click until it finally cranks, and starts on the fourth or fifth try. This is only when dead cold, first start of the day. On the other hand, in a day of driving, each place I stop for a visit, or dinner, it starts right up on the first turn of the key.

Does this indicate I need the deep cycle battery perhaps in addition to a starter, or is this a typical symptom of needing the deep cycle battery? On any other vehicle, I would just run a charger on the battery, then begin to suspect loose connections, then lastly a starter, so any thoughts?

Thanks,
Michael

ANSWER: The deep charge battery was Jaguar's idea. I found that I could test to see if that was a reason for a no start when it would spin fast but not start. I connected a good jumper and it started.
I don't use a battery charger because most a pulsing DC current.

A "click" and a no start sounds like something else. When it goes click it can be a relay not connecting or a  starter solenoid not connecting, a dead spot on the commutator of the starter or even a bad battery or ground connection.

The only way to test that is to put a test light on the white w/red tracer wire on the relay and make it just "Click". If the test light lights up it is not the relay. Then you need to put the test light on the Starter motor post of the solenoid and have it "Click" and if it lights, the starter or battery cable is at fault. The ground test is easy, just put the clip of the test light on the battery negative and the probe on the engine itself and if it lights up on a "click", you have a loose ground. Another test of cables (+ and -) is to turn the head lights on and hit the starter and if you get just a "Click" note if the lights go out which is an indication of a bad connection.

You have to test it in it's failed mode. (just a click)
Howard



---------- FOLLOW-UP ----------

QUESTION: Thanks,

So was I correct that the sunroof mech has to come out again to have headliner material fitted?

I haven't gone back yet to do the tests you described, but I can say that since I wrote the first question earlier, I did connect my battery charger, and it quickly indicated a full battery, as in the gauge went to "charged" as I watched it, within 2 mins. This suggests that the alternator is charging properly and the connections to the battery are proper as the vehicle was driven just three hours prior. What is the location of the relay you mentioned? Is that in the bank on the firewall? Also, peering in from overhead, I was not able to visually locate the starter. Is it best reached from underneath the vehicle?

Thanks again,
Michael

Answer
Yes, the sun roof has to come out but that is not a difficult job. But you should purchase a service manual which you need if you intend to keep the car.

If you are talking about what I said about the ser III needing a deep charge battery, it has nothing to do with the battery being charged. If you are trying to use a standard battery not a deep charge battery, do the test I outlined by adding a second battery in parallel like you would with a jumper battery to see if that makes it start. If it does, get rid of the existing battery and get a deep charge battery. The old battery may be just fine for any other brand car, sometimes for years.

There is a pack of relays on the firewall. A red one (not a relay) two black plastic relays, (main and fuel pump) and there is one metal can relay which is the starter relay. The 12 gauge white w/red tracer wire is the trigger wire for the starter solenoid so that wire can be tested there instead of at the solenoid. The starter solenoid is on top of the starter below the intake manifold so it is difficult to access without removing things.

Howard