So my wife calls me the other day to let me know the 05 XK8 won't start. Says it is going "click, click, click" when she turns the key and all the panel lights are dim. I'm thinking dead battery. When I arrive the ONLY two lights on the panel are the red lights on the oil pressure and voltmeter gauges (and they are on even when the key is not in the switch) When I turn the key I get absolutely nothing - no clicking, no lights, nothing.

I attach the jumper cables from the other vehicle and it starts right up like nothing was ever wrong.

Subsequently for the last two days it has fired right up like there was never a problem. I can see no indication of corrosion on the battery cables but have not had them off yet to clean them. I pulled the OBD2 codes and there are some cylinder misfires but nothing electrical comes up.

Any word of wisdom for me - ignition switch, relay, ...........????

 

Yes to those, but also check all the power connections. Especially from the battery to the main fuses, the batt. ground cable and the engine to chassis ground on the passenger side under the car.

 

Sounds like a partially discharged battery issue. If it's not a daily driver, it needs to be on a battery tender. Modern Jaguars are very sensitive to battery condition. Typical life is around five years although a few members have reported batteries lasting ten years and more.

The vehicle should go into 'sleep' mode which shuts down everything but essential security features. The ignition switch has a sprung cover over the keyway. If this doesn't close when the key is removed, it can prevent 'sleep' mode.

Graham

 

There was a posting recently that mentioned the 'junction box' that the cable go's into from the battery, the connnections may need tightening. It happened a few times when I first got the 'cat', the lights on the dials would flicker and it wouldn't start. After the bolts were nipped up the issue went away.

 

The note about oil light on key out of ignition made me think of the old key flap getting stuck open so car thinks a key is in the ignition. That'll deplete the battery too.

Look to see if removing the key from the ignition allows the little door/flap in the ignition to properly close.

John

 

As usual you all provide a wealth of information - thanks for the input - now all I need is the time this weekend to check it out!

 

To the OP, what was the final solution? I apologize for resurrecting a year-old thread, but this is EXACTLY the issue I have.

So far, after my first 5000 no-issue miles post purchase (at 96k miles):
1. First time, it started working again on its own when I came back to the car about 90 minutes later. Got home, battery charger showed low (72%) battery. Charged fine. Started fine.
2. Second time, my daughter was close and we jumped it. Started easily. Took it home and battery charger said low charge (70%). Charged fine. Started fine.
3. Third time, got frustrated and replaced the battery, even though the previous battery was a one-year old Autozone battery which both they and I confirmed seemed to be fine. Started fine with new battery.
4. Three days later (moderate driving) same issue. Jumped via starter box. Ran fine on the way home. Charger showed low battery (68%). Charged fine. Started fine.

All happened over about a 3-week period. When running, the OBDII reader is indicating 13.8-14.1V as reported by the ECU. The gauge on the dash always shows dead center 13V, of course.

My current theory is either a failed/ing cable or corrosion at some terminal. I have disconnected, sanded and replaced all of the pos and ground wires in the trunk (boot). As of yesterday, I am now checking the battery voltage with a multimeter prior to each trip. Don't seem to see a significant drop in voltage in the battery prior to starting the car, (has ranged from 12.5 - 12.8V). So far so good. I'm hoping messing with one of those cables was the magic pill, but not confident taking her very far afield.

Question for the WOTG: Is there a fuse that protects the circuits driving the oil pressure and voltage gauges? Seems weird that I would get those two lights on, albeit very dimly, with no key in the ignition.

I'll report back after some more time (opportunity to fail) has elapsed. I wish everyone would do that...

 

Kevin,

The OP's statistics show Last Activity: 05-16-2018 so it's either fixed or he's stuck somewhere.

The checklist is in this thread:

1. battery charge and condition
2. connections to High Power Protection Module (see item 5)
3. flap in the ignition switch stuck open




The terminals in the HPPM can loosen or start to break up. A regular cause of starting issues. A stuck igntion key flap prevents the vehicle going into "sleep mode" and causes rapid battery discharge.

Graham

 

My sincerest apologies - didn't mean to be rude by not adding to the data base. The new battery did the trick. My best guess at this point is that one of the plates in the battery may have come loose and occasionally caused a dead short internally depending on how it was jostled about during driving. I'll try to be a little more timely next go around - you guys are an awesome group and greatly appreciated.

 

I believe I have finally figured out the solution for this intermittent issue. I was able to replicate (actually, was plagued by!) the "disconnected" battery nearly daily and found that I could "reconnect" it by jiggling the braided ground wire. I have replaced that with one that NAPA has made for me and the issue has never resurfaced. I can see no corrosion in the original cable, and I had previously cleaned the post and nut, but there must be an internal (not much internal to a braided cable, I agree!) issue.

Either way, I am back up and running and a happy driver.

 

I imagine that sometimes the end connector crimps just aren't crimped tight enough. Doesn't take much oxidation in there to starve the starter motor.

 

Certainly not the first to encounter this problem, let's hope others take note.

 

Glad to hear you are back up and running. Over the years I have found that even if an electrical connection appears to be tight the slightest bit of corrosion between the metal connections can cause an intermittent condition. Clean everything well and use the dielectric grease!