I'm at my wits end and no amount of reading on here has lead me to any conclusions yet. First off, I have a 2007 LR3 with the 4.4 engine. It has lived it's entire life in the American southwest, so it doesn't have a single spot of rust on it anywhere thanks to our dry climate. About 4 or 5 months ago, I started noticing a hesitation when I would go to start it. Turn the key and nothing would happen, before I could turn the key back off, it would crank and start. This would happen maybe once or twice per day. Occasionally I'd get a check engine light and when I read it out, it would tell me it was a camshaft sensor. I'd reset it and it was good for 2 or 3 days. About 2 months ago, when it would hesitate starting, all sorts of warning lights would come on. If I read it out, I got no errors. If I merely shut it off, allowed it to reset, it would start as normal and work fine. This might happen 2 to 3 times per week.

Fast forward to a month ago. I stopped at the store on my way home from work (a 25 mile drive each way). When I came back out, I tried to start it and nothing. No click, nothing. I caught a ride home and had my neighbor drive me back with some jumper cables. Didn't hook up the cables, but tested the battery with a good (Fluke) multi-meter and got 11.9 volts. Out of curiosity, without hooking up the jumper cables, I gave it a try and it started right up. I drove it home and while the engine was still running, I checked the voltage - 13.5 volts. Figured it was a bad battery as it was 3 years old (in Arizona because of the heat, you don't really buy batteries, you rent them as they only last about 3 years). I left it on a charger overnight and then went and replaced the battery the next morning. Everything went fine for about a week.

After driving home one night I had to run an errand. I made it about 5 miles from my house and all of a sudden I had all the crazy warning lights come on. I started to get off the freeway and got a warning message saying speed restricted. I limped it onto a side street and shut it off. As soon as I saw the dome light come on, I knew I had a dead battery. Grabbed my meter and sure enough it was below 10 volts, closer to 9. Called for a wrecker and had it towed home. Once I got it home, I put a high output charger on it and started it up. Checked the voltage and it showed about 10 volts with the engine running. Alas, I figured it was the alternator! Should have checked that before I paid $200 for a new battery. Oh well. So, I slow charge it overnight and then drive it to my mechanic the next morning. I leave it with him for the day. The owner of the shop calls me that night and tells me that they really don't want to change out the alternator, because they have now way of determining if it's the alternator or the computer or both. Feeling confident that it was the alternator, I make a deal with him. I won't hold him responsible for any warranty or any follow up if they just go in and replace the alternator. This is something I could have done myself, but I couldn't see myself laying in my driveway with 105F heat bearing down on me. I buy an aftermarket alternator and have it drop shipped to the mechanic. He calls me that afternoon and says it's working great. I pick it up the next morning.

I drive it for a couple of weeks and then stop for dinner on my way home from work. When I come out, same old thing, I turn the key and nothing happens. I check the battery voltage and it shows 11.75 volts. I try a cheapy jumper pack on it and no change. I get frustrated and am about to call for a tow truck when I just keep jamming it over to the start position, when bam! it started right up. Now, I'm think ignition switch, or bad spot on the starter brushes, maybe the solenoid, I dunno. I drive it home and turn it off. I try it 5 times in a row and it starts just fine. Go to bed, get up the next morning and debate with myself if I should drive it to work. I go out and start it and turn it off 5 times in a row. I've now convinced myself it's a bad spot on the starter, so I drive it to work. Half way to work, I hit a bump on the freeway and I get all sorts of warning lights. I continue to drive it with no loss of anything and get to work. Grab my code reader and it can't explain any of these warning lights. So, I shut it off. Try to start and nothing. So, I leave the hood open and go into my office for the day. I come out about 3PM and try to start it and nothing. I played around with it for 3 hours. I pulled out the ground cable from the battery to the body, no rust, not corrosion, no nothing. I clean it up with a steel brush anyway and put it back in. Eventually, I locate the starter relay in the under hood fuse box. I jumper past it. I hear the solenoid clicking, but nothing. I'm now convinced the issue is the starter or solenoid so I call for a tow truck. They tow it to my house. The next morning off to the mechanic. He keeps it 3 days and calls me and says they can't condemn the starter because it appears to be starting just fine. He said the battery was dead when it came in and suggested that even though the battery was new, perhaps it was a bad cell in the battery.

I drive it home and take the day off of work to look into this. I check the battery, it's showing a little over 12 volts. I turn on the park lights and emergency flashers and let it sit for 45 minutes. I check and the battery is sitting at 11.5 volts. I turn off the lights and watch the voltage slowly start to climb all the way back to about 12 volts. If it's a bad cell in the battery, it won't recover on it's own. So, that's not the problem. I start it up and bam, it jumps up to about 13.8 volts and remains there while I have it idle for about 5 minutes. Okay, my new alternator is good. Then I decide I need to have a way to monitor the voltage to see what's going on. I use a cheap panel mount volt meter and wire it (through a fuse) directly to the battery. I run that on a long wire where I can run it from under the hood, through the passenger door and sit it above my glove compartment. I roughly calibrate the meter with my Fluke meter (see attached photo). Sitting still, no engine running, it's around 12 volts. I start the engine and it spikes up to 13.2-13.8 volts.

So, that night I have to drive about 12 miles to visit my wife. Starts out and it's at 13.2 volts. Then as I drive it slowly drops down to about 12.5. It floats around there most of the time, occasionally jumping up to 13.2 like when I step on the brakes. I'm thinking at this point it's working as it should. Then after I drive about 10 miles, I see it drop to 12.2, 12.1, 12, 11.9, .... it gets all the way down to 11.2 as I exit the freeway. At this point I'm calling in all my reserve prayers just hoping to get to my wife's house before it dies. Once I exit the freeway, I make a left turn and bam, it jumps back up to 13.8. It remains there for about another 10 minutes. I'm now sitting in my wife's driveway (did I mention we are separated?) and I just have it idling. It's staying between 12.5 and 13.2. I idle there for about 10 minutes and all of a sudden, it starts dropping again. I let it go all the way down to 10.5 and then I shut it off. I immediately restart it and it jumps back up to 13.8. Finally, she shows up and I shut it down.

I spend about 3 hours at her house (no details here) and then I start the 20 mile drive back to my house. It goes along between 13.2 and 12.5 for about 10 minutes of the drive. Then slowly it starts creeping down. I finally make it home and it's at 11.1 volts. I shut it off and restart and I'm right back at 13.8. I've been driving a backup vehicle all week (a 2000 Nissan Xterra, which has been much more reliable as of late). But every evening I start up the LR3 and it's fine for about 10 minutes then slowly the voltage drops. If I let it go, it will go down to the 10 volt range. Lights on, off, air compressor up, down, seats up, down, forwards and back make no difference. It runs fine for about 10 minutes and then the voltage starts creeping down.

I've read some references here to replacing the brake light switch, but I'm baffled by that one. Can someone please explain to me how the brake light switch would have ANY control over the alternator? The only thing I haven't checked is the ground cable between the frame and body. I'm hard pressed to believe in our dry climate that could be the issue, but I have it up on jack stands at the moment and that's my next adventure. I can try to have the alternator replaced again, but I'd have to pay for it all over again, since I agreed I wouldn't hold them responsible if it didn't work. I'd rather NOT keep throwing money at parts. I'd rather find the actual problem. Don't get me wrong, I've owned about 200 vehicles in my lifetime and my Rover has by far been my favorite...... until I have to work on it!!

Can anyone here please help? (as a note, don't just say stuff like "13.2 isn't enough voltage", please give me some guidance on how to correct the issue).
Here I'm trying to calibrate the cheapy little voltage monitor I built to throw on the dash while I deal with this issue. Yes, I made the laser cut case for the panel mount meter.

 

you might want to check the alternator fuse in the battery fuse box. I think that it is fuse number f20. the fuses can start not to sit correctly and you can get inconsistent voltage. I recently had to wire around the fuse and add an independent fuse. now all is good. I recently posted on the issue. phil

 

See that little black box on the side of the battery connected to the positive? Pull that all out and open it up. This is your main power fuse that sits between all the electrics and on the other side the starter and alternator. While you are in a dry climate, if anyone has recklessly washed the engine bay at some point water can intrude and cause lots of corrosion on the strip fuse. Is even possible the strip fuse itself has cracked causing intermittent issues (this is a BIG problem on E32 BMWs).

 

I checked the alternator fuse as you suggested. The fuse was good as well as the socket. Oddly enough, with the engine running, removing that fuse caused the alternator to go to full output. Put the fuse back in and behavior is normal. I need to investigate this a little further. Still checking! Thanks.

 

Thank you for the tip on the main fuse. As indicated in the photo, I opened that up. Everything appears fresh and clean. I removed it and gave it a good wire brush cleaning just to make certain. But as you can see by the photo, it was fairly clean to begin with. Thanks for the help, but the problem still persists.

 

 

Thank you for the reply! I pulled the black fuse holder off of the battery and checked that fuse. Everything was clean with what appeared to be good connections. While I had it opened, I used a stainless steel brush and cleaned everything up as best as I could. I don't think this is the issue, as it continues to quit charging after about 10 minutes of driving. Thanks for the tip however! I tried to post a photo of it up, but for some reason it doesn't show up when I attach a photo.

 

It sounds like you had the same symptoms that I was experiencing, or at least some of them. You might try routing around the fuse box for the F20 fuse with a separate stand alone fuse, you can clip it in place with the clip-style connectors. My RRS has been running great since I did the fix. $7 in parts from Oreilly's. You can take it off if it isn't the issue. Phil

 

ljdiscovery (Phil), thanks, I checked the socket for the fuse yesterday. I pulled up the fusebox and connected clip leads across it with a multi-meter on it. I wiggled the fuse all around and could never get it to produce an open circuit. I checked and triple checked, so I feel pretty confident that the fuse and holder is in good shape. Although I was really curious that when the engine was running with a VOM on the battery, it went to full output when I removed the fuse. I thought for certain the alternator would just quit when I removed the fuse. I may try a little experiment to see if I can use that as a reset once I notice a voltage drop when I'm driving.

On Saturday night I went for a long drive to meet up with a friend. All total about 30 miles one way. Well, I made it all the way there and everything seemed to work correctly. The voltage never dropped below 12.2 volts, even with the headlights on. Then on the return trip home, I only made it about 3 miles and the voltage dropped all the way down to 11.7. I know that once it drops much more below that, I can't start it. So, I pulled over, shut everything down and restarted. It jumped up to 13.5 and stayed there for a bit and I'd watch it suddenly drop to about 12.5, then slowly drop all the way to 11.7 again. In all, I pulled over and restarted 3 times in 30 miles. However the last time I did it, my trick didn't work, the voltage never jumped back up. So in addition to it being an intermittent issue, I now feel it's temperature related as well!

Thank you for the tip. I feel pretty good about the current alternator fuse and socket, but I'll keep looking!

 

Are you sure that the alternator is good. You might find a replacement at a wrecking yard and swap it out and see if that fixes your problem. It if a fairly easy swap out. You can check on car-part.com for wrecking yards in your area. Phil