Ive looked for this specific problem but havent found any with this exact problem. On my 03 disco (75K) I replaced the alt because the srs light was coming on and the alt was getting low in the volt output. After replacing the battery light starts randomly flashing no rhyme or reason that I can figure. Voltage at the batt is around 14 I think and it isnt spiking or failing. I put the multi on the batt while the light flashes and there is no change in reading. Double checked all the wires they are tight and continuity is good. Its been happening for about 2 months and the battery hasnt died its even sat in the cold for 5+ days and starts right up. Any ideas or help would be much appreciated.

 

You bought a re-man from a auto parts store didn't you?

 

I just had to go check it was from partsgeek usa industries but yes on the reman

 

The light comes on if the voltage out of the alternator is less than the battery voltage. See attached schematic from the RAVE electrical circuits manual. A loose connection, or cracked fuse could also cause this. Also a skinned wire (the brown with yellow small one) that hooks to alternator.

Battery volts goes thru that light bulb from Fuse 27 (under dash) to the alternator on a brown with yellow wire. Can't have any loose connections. That voltage excites the alternator and makes it produce power. The alternator power output goes out a big brown wire and ties into the electrical system thru a 150 amp fuse link in the underhood box, it needs to be tight.

Spike is right, if you don't have any other wiring problems, about the only thing that can make the light come on is the alternator itself (brushes, windings, regulator). Reman folks are ruled by a race of savage bean counterz, who have found they can save money by using the cheapest parts available from China, where quality is not job 1. Many owners have found that they will have several failures on reman alternators for Rovers. Mine died twice, keep you warranty receipts.

 

Could I ask what you paid for it?
Did you match this reman to your old one by part number, 03 and 04 take a different alt. the the earlier 99 to 2002 models?

 

Ill check that stuff thanks for being so detailed. It was 120 with a 75$ core. I didn't check the part number I just did the search by year make and model ill double check what is in there. I've learned to save the receipts after getting burned a few times haha

 

So Ive done some research and found there are 120 and 130 amp alts. Im assuming the problem is I got a 120 instead of a 130. My part number from parts geek is Part #: A2990 Qty: 1 2003 Land Rover Discovery Alternator which is the 120 amp. It also said the vin has an indicator of the 120/130 as a 4/6 but I cant find where in the vin it is. Since I have both a 4/6 in my vin I cant determine the proper solution. (salty16453a786293) If you know the corresponding location in the vin please let me know where I need to be looking for a 4/6. Also I didnt check the part number on the stock alt before I sent it back in which Im sure would have saved me this entire headache. Thanks again

 

They most likely mean 4.6 liter engine. But while there are both 120 and 130 that fit, the alternator capacity is not the problem, unless battery is going dead while you drive. I have a 100 amp in my D1, and with all the stock lights, wipers, AC on max, brakes on, engine running; the drain is about 85 amps from the alternator. So unless you only see this light when every possible load is on there, it is more likely just a bad alternator. As an example, when the brushes wear down and loose contact, the light will come on/off. Some times brushes are not replaced. Sometimes brushes are mounted poorly. But they have to be there to connect the electrical enegrgy to the rotating part.

 

Well it sounds like ill get back to the month long replacement process, thanks for the help

 

Buy a used one off of e-bay, you'll have it in a week, put it on, send the other one back, when the replacement comes put that one on, keep the used one on the shelf in the garage.