I have a 2001 Disco II SE with 154,000 mi. Has been working fine. Drove it to work yesterday and when I went to start it at lunch break, it wouldn't crank. Had someone jump-start it and it fired right up. I went around and checked all of the accessory lights, doors, headlights, glove-box etc to make certain that nothing had been left on. Drove it home about 7 miles. Turned it off and then tried starting it again. Fired right up. Did this several times and then decided to take my car back to work until I could look at the Rover.

Went out this morning to start it and battery was dead. Took it out and re-charged it. Upon reinstallation, it started right up and ran fine. Unhooked the positive side cable and I put my test-light between the positive battery post and the positive cable it lit up, which indicated to me that I had a draw someplace with the vehicle turned off. I exchanged the test-light for my volt meter and it indicates 12.4v, the same as the battery. I left the volt meter in place and pulled fuses one at a time with no change. Same with the relays. This includes the fuse panels under the hood, under the steering wheel and under the seats. No change to voltage draw. Pressed the hood detent, no change as well.

There is an obvious draw somewhere because when the positive cable is touched to the positive post, there is a slight spark and to my knowledge this should not happen with the vehicle off. Went back and double-checked all of my lights everywhere. Checked the doors for secure closure. Turned the alarm system on and then back off again. Pulled the positive side and test-light still lights up and volt-meter reads battery voltage between positive cable and post.

Any ideas on what might have happened to cause this sudden draw on the battery and are there any common problems of this nature with my particular year and model rover?

Thanks

 

You can not jump start a dead battery and expect it to recharge by driving for a couple of miles. You most likely need a new battery. To verify, jump it again then go down to your local parts store, get a free charging system test done and go from there. If you need a battery get an 800 CCA rated battery or higher.

 

I'll take it to be tested this morning and thanks for such a quick reply, Mike. Regardless of the battery itself, should there be a 12v reading between the pos battery post and the positive cable with the vehicle turned off?

Russell

 

Yes, because there is a path from the (+) wire thru fuses to multiple devices that are always on (ECU, other modules, clock) to ground. Bu this should be a very low current. You can repeat your test with meter on amps, and not only pull fuses but also remove fuse links as well. Some fuse links run one device, others act like a main breaker ahead of other fuses. If amp meter not available, a turn signal bulb in series between + battery post and battery lead will light up bright on higher drains. You'ld be looking for over 100 milliamps.

Mike is right on the takes a while to recharge, when I put a clamp on amp meter on my D1 as little as 5 amps was headed back to the battery, the rest was going to run the various items on the truck. If your battery is being charged, the alternator volts across the battery when running will be 13.6 - 14.4. Turn on stuff in the truck and it may go as low as 13.2. If alternator is not putting out full amps it will drop below the 13.2 when you turn on high power loads like AC and fan, head lights, etc. If battery is holding a charge, with truck off read the volts. Let's say you get 12.9. Switch on the headlights - should not drop like a stone to 10 volts, etc. If it does, there is a weak cell in the battery. Most batteries are built for a 3 year life. Some get more some get less.

You can also get battery read for free at parts store, soetimes you want to try two different stores (various equipment and trainees).

 

You should be seeing about 14 volts with the engine running if it's charging. You were reading battery voltage which means nothing. Volts are worthless without amperage.

First thing in the morning before the truck has been started pop the hood and put your hand on the alternator, if it's warm you have a shorted diode bleeding the battery dry.
Replace alternator and maybe the battery if it doesn't pass a load test after being fully charged.

 

Thanks to everyone for all of the assistance. I'm headed out to get a battery replacement if one can be found on Sunday here If not, Monday. I'll post the outcome of battery replacement and charging system.

Russell

 

Okay. Purchased an 84-mo 800 CCA top-of-the-line battery replacement. Had the old battery tested at two separate locations and both said it was only indicating a need for charge. I told them that I had already put it on full charge with a battery charger only this morning and they stated that it was subsequently "not holding a charge."

Charging system reads 14.39 at idle with no accessories and with every accessory on, I get 13.93.

The litmus test will be when I go to head out to work at 6a in the morning and it hopefully fires right up. I'll check the diode on the back of the alternator for heat before cranking it over. I'll keep you posted and thanks again to everyone for their assistance.


Russell

 

Sounds like the battery was toast. Hopefully this is the end of the issue. You are seeing proper numbers from the charging system now so I doubt you will have further issues.

 

If diode was short or open, you would not get enough amps with all extra devices (max load) on to maintain 13.93 volts, so you should be good to go.

 

Went out this morning to start my Rover and . . . . . . .started right up. No problems.

Not only am I thankful to everyone for their assistance, but based upon my own original interpretation of the problem I am extremely thankful that I chose the medical profession rather than mechanical for while I've never lost a patient over the years, I fear that by contrast I would have already lost a lot of vehicles by this point in time.

Many thanks!

Russell