Here we are as of yet; battery terminals are clean, battery on trickle charger, ground to battery is secure, ground to fuel pump is secure. I read in other threads about the box behind the battery that can suffer from moisture and subsequent corrosion is good. If the fuel pump were to suffer a malfunction or not perform properly, would it throw up a trouble code?

 

Mack73, I have access to ALLDATA but my scanner is down. When I get a new one (soon) I'll send you a PDF of the ground locations. There's a butt-load of them.

 

I've seen a few of these early on (circa 2005) where the fuel pump connector inside the tank is loose on the filter/tank cover. This will cause an intermittant stalling complaint. You would need to remove the tank and open it to see this. I've also seen a couple of bad fuel pump relays. Neither of these 2 suggestions were problematic but they can and have happened...

Cheers

 

Land Rover uses some odd system related to ground wire theory but the short answer is that there are ground studs all over the place.

The ground stud that probably most concerns you however is about a foot away from the negative battery post - on the inside fender in the space between the battery and the fender. It is a bit hard to get at but you can.

Just follow the ground cable off the negative post and you will see the stud. You might try to wiggle it or tighten it a bit.

Also there seems to be a history of problems with that ground cable - internal corrosion I gather which means you cannot see it. The part number of the cable for the LR3 is YTB500300 and costs about sixty dollars.

There is a second separate thick ground cable sort of under the engine but the skid plate has to be removed to find it - connects between the engine and the frame I think.

 

Update.. Charged the battery to 100% drove for about 25 min. At about 20 min in I got a rough idle A/C was on, headlights on, radio on, nav, etc. At 25 min it died. No RR tracks or bumps in the road. Got it restarted in a minute or two drove another 1/2 mile home put in park. While rolling up the windows it died again.Put the charger on it and it read 40%. Any thoughts? Bad battery?

 

I'm going to pull the alternator and have it bench tested for direct amp output. Question is, is there anything in between the alternator and the battery that would effect charging of the battery?

 

The Engine Control Module is between the alternator and the battery.

Actually it is the "regulator" that is between the two but the regulator takes it instructions from the ECM in the form of a PWM, (Pulse Width Modulated), signal. That is what makes troubleshooting so difficult. The alternator may put out in a test but the regulator is defective and will not allow the alternator to function during routine operation. The regulator has a default program where it operates like a normal old regulator in the absence of the ECM, as in at start up. Fuse F20E initially provides power to the regulator like the old B+ terminal of yore.

From your previous posts, it appears both the battery and alternator are OK.

Before you start removing stuff, try to determine is how much of a draw is from the battery when all is shutdown and asleep.

The draw should be less than 0.5 amps.

Making this measurement is harder than you would think as the bonnet has to be open, but if it is, the alarm system is alive. You have to fake the bonnet alarm switch into thinking the bonnet is closed, (press the passenger side hood latch down into the locked position), and then roll the drivers window down and lock the vehicle. Pretty soon all will be asleep.

Measure the current draw by removing the ground cable from the negative battery post and inserting an amp meter between the battery negative post and the negative end of the ground cable - this is safer than using the positive - fewer sparks if you drop something.

More than half an amp suggests something is still on so start pulling fuses, first in the engine fuse box as it is easy to get at. Hopefully it is something there as opening a door to get at the lower glove box fuse area wakes up the 3 as the interior lights go on. As such, you have to kill that circuit so the process is not an easy one.

Basically you are looking for something that is drawing the battery down even when the charging system is supposed to be working - heated seats, windscreen, radio amp that will not depower etc.

I went thru this process and discovered that the overhead DVD entertainment system would not shut down and that the screen was active even with the lid closed - but not all the time. You could have a starter motor or solenoid that is drawing power but still works for the most part. I suppose even the alternator itself can do that as well.

 

Thanks bbyer, I'm going to give that a shot tomorrow. If the current draw is indeed less than 0.5 amps whats next? I've looked for but can't find the location of this "regulator". Is the name of it "voltage regulator"? Should I even be concerned with it if you said that it defaults to a normal regulator type function?

 

As to what next, I am not so certain if the when asleep, the amp draw is near 0.5 amps which suggests OK. Actually I think probably it will be OK as the high amp draw could be only when the vehicle is running so not enough current is left to charge the battery, yet no warning lights go on.

I guess the next procedure would be to measure again the amp output from the alternator, (not into the battery), when the 3 is running but with as much off as you can make off. That means no radio, no lights, etc. The number should be a lot closer to 50 amps than 150 amps, the supposed maximum output of the alternator. I guess really the number I am looking for is the amp draw into the starter motor - should be zero when the starter motor is not working.

The regulator, or what what would be called the regulator is built into the alternator as is common on most alternators.

Near the middle of the link below are five files specifically related to the alternator and internal regulator including a pdf of the pin out and wiring diagram. These you can download and print off. My view is that with this PWM signal stuff, the regulator should be separate from the alternator as they were years back and be located in an area of cooler air or at least more ventilation - kind of like the days of old time generators.

[DISCO3.CO.UK Photo Gallery - LR3 miscellaneous

 

Below is an interesting link re somewhat the same problem.

Alternator - Not charging - Australian Land Rover Owners

I am beginning to think that maybe of our electrical problems stem from how LR runs the cables from the alternator to the battery. Note the plural, cables.

The alternator cable first goes the the starter motor and then up to the battery. This can cause some challenges when trying to diagnose a starting or battery problem plus it adds in more variables.

This is so Land Rover.