Draining Battery, need help

[Borntoburn]

CAUTION: A word of warning about using a test light.

I urge anyone using a test light for diagnosing circuits to invest in a test light that is rated safe for use with digital circuits. They can be had for around $10 and are a wise investment against causing damage ($$$) to your vehicle's digital components.

Your Rover, like all vehicles built since the mid 1980's, is strewn with digital components and tiny computers that are VERY sensitive to amperage. Believe it or not, the tiny lightbulbs used in cheapo test lights pull enough amps to fry microprocessors under the right circumstances.

You can get away using a cheapo light... but that one time you screw up and fry a computer will be an expensive lesson you won't soon forget. It happens more often than you think.

 

[Papillon]

Thanks be to DWeb posters!

I too was having a dead battery problem. Turns out the voltage regulator in my alternator had developed a "taste" for about 400 milliamps of power. As the truck sat, the alternator quietly sipped away on the battery. After about 4 days of sitting the battery would be drained to a point where it could not start the truck. Following all of your good advice and using apg's low tech light technique I was able to identify the alternator as the likely culprit and have it locally repaired for about $100.

It should be noted that there will always be a small amount of parasitic drain present (due to the clock, radio memory, alarm, etc) probably in the 50 milliamp range and therefore the test light will always have a faint glow, but if the glow seems brighter than it should be, more than likely you’ve got a problem somewhere. Start pulling those fuses to identify the problem. An fused amp meter would be the tool of choice, but the light technique works, and well… it’s a “bright” idea. Thanks again.

Papillon

 

[frickjp]

If the alternator is killing the battery in a day, it will be warm after sitting overnight. Test done, no tools required.
If you need a new alternator, IAT in NYC has brand new Marelli units for $150. We ordered 2 more Friday, still in stock. I just can't justify telling someone that they need a Land Rover alternator at $600-900. They're wholesale, so make a up a shop. They have the small pulley 100A and the 120A Range unit. I'd suggest the latter. The 94/95 has smaller pulley, but the smaller pulley charges more at idle anyway. Your tach will be off a bit, so what. If you're bothered by the tach, change the pulley. If you're a cheapskate like me, the voltage regulator is usually the culprit for parasitic alternator drain, they have those as well for about $20. Get genuine, not the cheapie. The cheapies never last.

 

[ptschram]

I just can't justify telling someone that they need a Land Rover alternator at $600-900.

Don't forget the $140 core charge on a brand new part:banghead:

 

[frickjp]

Don't forget the $140 core charge on a brand new part:banghead:

Did you happen to catch the price of a starter lately? A year ago, they were $150 or so. Then $521. Then $380, now $528. And a $140 core. They don't want to sell starters? For $528, I'll engineer a hand crank!