Hey guys so have been running quite trouble free for the last couple months besides small stuff here and there... so I guess the Rover Gods noticed and thought they would send me some love.

My battery light has intermittently come on, but now it is coming on and staying on.

Alternator? How do I check the charge of the alternator? I took it to AZ and they said they could only check the battery. Battery showed that it needed a charge. (Battery is only 6 months old though) The guy said it was probably an alternator problem, but I just want to make sure before I go drop $300 on a new one from BPUtah...

It has had no starting issues, but idle does seem a bit weaker...

 

Light comes on when alternator volts less than battery volts. If truck is running at idle, should have 13.8 to 14.4 volts across battery. As you turn on more loads (head lights, AC, wipers) the amps increase and the volts will drop a little, but should not drop below 13.2. If you have a bad alternator regulator, or a bad diode, you alternator may put out good volts at low amps, but under higher load can't supply it and volts drop. Plenty of parts stores can test alternator, usually when out of truck. If flickering on/off, it is usually the brushes that have worn down and are dropping out of contact. In a few more miles they will be worn so much no contact. Then you run on reserve battery minutes until battery exhausted. Then you hope cell phone has bars.

 

If you do need one, check with Trevor at Rovahfarm, he's generally cheaper.
Also check with local auto electric rebuilders, the are often cheaper.

 

A NEW bosch alternator is 232 at rock auto, but for some reason you have to look up the wrong year.

 

Got mine out of a salvage yard for $50 bucks and installed it myself. 40,000 miles on it since I aquired it and still running strong. Couldn't justify spending over 300 for a AutoZone special when I could get a Land Rover part for $50 bucks!

 

if there is an advance auto near you i know the ones here do a full charging system check that test load on/off to make sure the currents correct. like they said you can get an idea from the voltage reading across the terminals with a voltmeter and see if its 13-14v's but youll need an inductor on the wire to check if the amps are flowin too... you can get a pair of 9v flashlight batteries to read 18v's but theyre not going to start or recharge a car haha.

if no one does the charge test only other thing you can do is charge the batter up independently, take it out and bring it in for a thorough test to make sure it doesnt have any bad cells or other problems. what year is posted on the battery? it might just be on its way out, most only live 4-6 years roughly depending on how active its life has been to begin with lol. if the battery tests out ok and you still get the light, it might be pretty safe to assume the alternator might be the issue assuming there are no other obvious causes such as frayed lines/wires/grounds anywhere.

 

Thanks everyone for the replies.

So far I have been able to drive it without any real issues except the light being on. I went wheeling this weekend in some pretty fun mud and so I thought I would run her through the car wash. Of course this is the place she decides to die! Haha, four cars behind me in line, and I get out and have to push the poor girl out of the wash. Of course because of all the water around, it's super icy and pretty tough to push the pig around, but I was able to get her out alright while my wife was steering. I then asked a fellow car wash attendant if he would give me a jump. He was happy to help out. I told him I had a bad alternator and that if he didn't mind, I would probably let her charge a couple minutes. No worries. So I get her charged up for about ten minutes (we were really close to our house, so I thought she would make it) Of course driving home we hit every red light. On the second red light, the classic M+S lights started flashing, all electrical things started turning off one by one... including my instrument cluster, then it turned off. I coasted her up onto a median (really no where else to park her unless I wanted to block traffic completely) Luckily I was close to home so I walked home, got my other car, went back, hooked up the jumper cables and let the battery charge for about fifteen minutes. I was able to start her right back up and get home where she sits now until I get my new alternator in tomorrow. Thankfully I had ordered the new alternator last week from BPUtah and it was already on its way. Wish I had time to visit here and see the Rock Auto alternators for $70 cheaper! But all is well and I should have the new alternator in tomorrow when it arrives. Looks to be a very straightforward job and shouldn't take more than an hour to do...

@gradkodiak - battery was installed about six months. Shouldn't be going dead. Hopefully the new alternator will fix the problem!

 

cool good luck... just make sure the battery is fully charged before swappin in the alternator

 

Hi bballjames, I know we're talking about 7 years ago, but I'd love to know what happened afterwards. Was it the alternator afterall? Thanks in advance!