Ls400 Flat Battery

[LWR]

I have a 1997 LS400 that flattens healthy batteries in only a few hours.Overnight is more than enough.

We've checked batteries,drains etc but I now I think that it only happens when we forget to lock it.

Our LS430 and SC430 seem fine,locked or unlocked.

Anyone had this problem?

[SKperformance]

Need to check it again with the car locked then.

What is your alternator output voltage?

Turn your dome light to off from door and see if it makes a difference.

[LWR]

Need to check it again with the car locked then.

What is your alternator output voltage?

Turn your dome light to off from door and see if it makes a difference.

Thanks!! Will do.

[cardona6569]

Hi: I do believe you will need a new alternator. Had a problem like that on an 87 Cougar, the battery was fine, the car while on, had no problem it even charged fine, the electric metter read in the normal, just leave it couple of hours off and the car would not crank. Check the cable connections and voltage output if the battery is normal then go for the Alternator. The night before this I even ran the car at 80 to make sure the battery charged the next morning did not crank, went to change battery, the store said my battery was good as new, then replaced the alternator, problem solved til the day I sold the car. It is that somewhere in your car ther is an open circuit when your turn it off make sure you do not leave any lights on!

C. PR

I have a 1997 LS400 that flattens healthy batteries in only a few hours.Overnight is more than enough.

We've checked batteries,drains etc but I now I think that it only happens when we forget to lock it.

Our LS430 and SC430 seem fine,locked or unlocked.

Anyone had this problem?

[LWR]

Hi: I do believe you will need a new alternator. Had a problem like that on an 87 Cougar, the battery was fine, the car while on, had no problem it even charged fine, the electric metter read in the normal, just leave it couple of hours off and the car would not crank. Check the cable connections and voltage output if the battery is normal then go for the Alternator. The night before this I even ran the car at 80 to make sure the battery charged the next morning did not crank, went to change battery, the store said my battery was good as new, then replaced the alternator, problem solved til the day I sold the car. It is that somewhere in your car ther is an open circuit when your turn it off make sure you do not leave any lights on!

C. PR

It looks like it is the alternator. It looks like the P/S pump has been leaking fluid over it and it charges at less than 12V.

I had all the same frustrating troubles you did!

I have a 1997 LS400 that flattens healthy batteries in only a few hours.Overnight is more than enough.

We've checked batteries,drains etc but I now I think that it only happens when we forget to lock it.

Our LS430 and SC430 seem fine,locked or unlocked.

Anyone had this problem?

[AzHotLS]

I also think it's the alternator. I believe mine is bad as well since my batteries keep dying. Finally got smart and bought a battery charger and charge it about every week.

Come to think of it, the smart thing to do, in my case is to just replace the alternator. If I can just find the time.

[cardona6569]

HI;

Quite possibly if you keep running the car with the bad alternator, you will damage also the battery and the starter, I seen it happen in the ole days.

But make sure this is not hapening because of the P/S Pump leaking which it usually comes from the High Pressure hose fitting. Most likely is the fitting itself that is removable and the burr can be fixed with P/S fluid and sandpaper, like done on plumbing, I fixed mine; likewise the dealer wanted to put a new High PS hose costing 500 plus maintenance fee, when in all reality all it needed was to the sandpaper trick. The Pump has a packing but it is on the inside of the pump, if that be broken is an easy fix also, but is is not visible, so must likely the leak is from the fitting that goes to the pump from the Hi-press side and can be fix with the above procedure, and doing it until it is somooth again. Mine already has a year no leaks at all. I also used a Barrs no-leak transmission treatment. I know many do not reccommend, my experience with is has been great. Remembering that your PS system uses Tranny fluid of the Dextron Family. C. PR

I also think it's the alternator. I believe mine is bad as well since my batteries keep dying. Finally got smart and bought a battery charger and charge it about every week.

Come to think of it, the smart thing to do, in my case is to just replace the alternator. If I can just find the time.