My 1998 XJR has a dead battery. How do I open the trunk to charge it? The remotes do not work of course, but when I turn the key in the ignition the console lights go on. I guess there must be a reserve power source?

 

Inlitero, you should have a + post inside the engine compartment. So, what you can do is since you can get into the passenger compartment, you can pop the hood and using a set of jumper cables and a second vehicle, you can use a set of jumper cables to temporarily supply power to the car to get the trunk opened via this post. Then from there you can charge the battery.

 

One enterprizing chappie on here crawled under the front of his car and clipped a 12volt supply to the starter motor. (Two leads requ. of course, and don't get them crossed, at your peril!) All goes live, end of problem.
Leedsman.

 

Thanks for replies, gents. Because I was able to get into the cabin and pop the hood, I hooked up my battery charger to the positive post at the fusebox and grounded the neg to the engine. I was then able to start the car without accessing the battery. For some reason my key doesn't open the boot lid, though it turned out not to be needed anyway.

 

Lateral thinking at it's best.

 

I have a 2001 XKR, and for some reason I could not get the battery to take a charge from the hot lug next to the big black box. I had left the car out on my car lift to inspect and/or change the left bank O2 sensor. and for some reason the battery went down to 1 volt. It has never done this before. Could it be that when you unhook wires here and there, it causes a drain on the system?

I used the lift to get under the car and attach the battery charger directly to the starter to recharge it since the key will not open the boot/trunk.

Since they tell you to disconnect the battery when doing service work, how are you supposed to open the trunk to reconnect it? Something isn't right about this.

The only saving grace would be to power up the car using that hot lug so you could open your trunk. Has anybody run across this before? Why can't I recharge the battery thru this hot lug while grounded to the engine? I can read voltage thru it.

Before someone speculates that the battery was so low I couldn't detect it charging. Please let me say that I could detect it when hooked up directly to the starter. I'm about to run an extra wire because we not so lucky always to be sitting on a car lift when we go open circuit dead.

 

Simply use the key to open the trunk. Those of you who say the key doesn't work, you need to spray some lube in the key hole because it probably hasn't been used in a long time, if ever.

 

Yes. That's the standard first step. My trunk lock doesn't engage at all. It's not a lube problem. I sprayed enough lube in there. Passenger door lock to enter the cabin, no problem, but bootlid no go. Anyhow, the hot post under the engine compartment worked fine.

 

The short answer Mark is, yes, unhooking wires CAN create a drain in the vehicle systems. Just depends what wires they are. Multiplexed systems have modules that have things to do after key off, then they go to sleep. [if all is right] If they are not properly powered, or are not fully connected, they can't do what they need to do and then power down. In many cases removing power to something wakes the electrical system up, and the very same disconnection can then prevent the shut down. Confusing, huh?

Cheers,

 

Thanks guys. I finally got the key to open the trunk with some hard jiggling. Still wondering about that disfunct hot lug.

Went for a jaunt and it left me. Had to jump start it. After a couple miles a lot of noises under the hood started. Put in a new 950 cca battery. Engine still running rough and smells like a gasoline leak. Alternator is charging fine.
Changing sparkplugs, the upstream left bank O2 and running 1/2 gallon of injector cleaner didn't help my random misfire at all. Cyl's 5,6,7,8. I checked the right bank cam tensioners since that is the easy side. They were perfect, and hoped the left side would be the same. Working on checking the left side today, because I got a severe rattling noise now since the battery quit on me. Sounds like the belt pulleys are loose. It's still throwing codes 1638 and 1642. I see what JTIS has to say about it, but it doesnt mean anything to me except that replacing an ECM is out of the question.

After I check the cam tensioners on the left bank, I'll switch all the ign coils from side to side. Doesn't make sense to have 4 coils go bad to me, but right now I have to eliminate everything I can. All the plug wells are free of oil and the coils look new. I'm hoping the gasoline smell is because the left bank isn't buring it's fuel properly for some reason. I fail to see how the cam tensioners could be causing this. (A cam sensor maybe?) I ohm'ed both cam sensors. They almost identical. I will give special attention to the camshaft itself. I would think the purge valve (fuel smell?) would cause some misfire on both banks in a SC engine.

 

Forgot to mention all the rough running goes away after 1,500 rpm, but the fuel smell is still there.

 

OK, ME AGAIN. I pulled the left side valve cover and lo and behold what I see but a loose secondary cam chain. Hummm. The right side was tight as a drum.

Could this be messing with the ECM?
Make a random misfire on the left bank?
Keeping the spark plugs from firing properly?
Smells the raw unburnt fuel from the back of the car permeating the interrior?
Sounds like pulley noises, but you can't hear or make a belt squeak?

We shall see. I ordered one from FORD to fit a 2004 Lincoln LS 3.9L with a pack of 4 bolts for under 100 bucks.

 

First thing you need to do is bump the starter and turn the engine until the two flats on the RH cams are parallel with the head surface. Then check the LH cams. If they are parallel as well, you're lucky, fix the tensioners and you're back in business. If they are NOT parallel like the RH side cams, you're out of time and may have tagged some valves, then you need to take the head off. Or at least run cylinder leakdown tests to check the valves.

Cheers,

 

Good info. Thanks Steve.
It hasn't jumped timing yet. It's still a long ways from that point. The car runs very good with only a shaky misfire at idle speeds. The compression is 180+ across the board. My XKR has 78,200 miles on it.
(My mechanic told me I had 4 bad coils and fouled spark plugs. Looking for a new mechanic that knows more than that.)
There are no bad coils and no fouled plugs. The MAF, MAP, O2's, KS, cam sensors, crankshaft sensor are all very good. Under the hood and under the car it all still looks like new. My firends and I am still very impressed with the quality of this car overall. It is very out of character for the car to be idling as rough as it is and it smells like leaking gasoline.
At this point the tensioner is just starting to go out on the left bank. The engine is strangely quiet for such a loose chain. The misfire does cause the gears in the supercharger to rattle a little bit but only under 900 rpm.
Thanks, Marc