i have a 98 GS400 and yesterday the battery complete died while i was driving, the Battery light had been coming on for the past few days but only for a second then it'd go away. took the battery in to get checked and was told it was completely drained and need recharged. got it back after being charged and now the light seems to come on after a few minutes of driving and only stays on while the car is at idle. if i rev it it goes away then comes back on as soon as the car gets back to idle. at first i thought the alternator, but it seems to charge it when i rev it but not at idle. any ideas? car is bone stock no aftermarket anything.

 

Sounds like an alternator problem. When you rev it, the amperage is raising on the output of the alternator. Usually when it doesnt sustain proper charge at idle, its a diode problem which can be fixed, but finding someone who does that is impossible and probably more to get done than to replace. Remove it and get it checked.

 

I'd agree with the alternator as the likely problem. Did you check your cables? Make sure both ends of both cables are tight and clean.

 

yes i checked everything, ugh it was hopeing its wasnt the alternator as they are around $200 to replace. good thing i love this car as much as i do lol

 

so i read that the problem is that the power steering pump can start to leak onto the alternator and that causes it to fail. is there anything i can do to fix the leak on the power steering pump without buying new one of those too? It just seems dumb to fix it with the possibility that it will just break again soon because the power steering pump continues to leak. i did look around the Alternator and there is alot of gunk built up around it but the power steering tank seems to stay full.

 

You make it sound like the Power steering is suppose to Leak.. WTF?

IDK but common sense would tell you, fix the leak and get your alternator checked and/or replaced.

 

There's products made to stop power steering leaks, might be worth trying one of those before you replace the pump. I believe Lucas makes a power steering stop leak additive.

 

I would never use a stop leak for any source. Stop leak is obviously gonna plug it, so what happens to the rest of the crap floating around? Chance to plug something else that it shouldnt... Just sayin.

 

not sure why you think i was saying that i think its supposed to leak, i was saying that i read one of the common causes on a GS400 is that the powersteering pump begins to leak after time (my car has 149,000 miles) and because the pump is right above the Alternator the power steering fluid leaks onto the alternator which causes it to fail. such as mine not chargeing properly at idle, and common sense did tell me to fix it which is why i asked if there was a way to fix the leak without buying a completely new pump(such as a seal or something of that nature that can be fixed instead just buying a new power steering pump)

 

ok so just got home and on the way i noticed the car was running sluggish and looked down and the ABS VSC, VSC off and battery light was on. drive it like 3 or so more mile home and then when i turned it off, i tried to start it again and nothing just a click like before when the battery was completely dead. so i guessing that it ran off the alternator the last 3 mile or so, which means maybe its just a bad battery? the car did sit for over 6 months before i bought it.

 

Your alternator is bad! Change it and fix your leak if there is one. Because you have been driving with a bad alternator, you will probably have to change the battery also. I had the same issues as you a couple of months ago. I changed the alternator, and haven't had a problem since.

 

ok thanks, ya the car wont start. and i got a 3 year free replacement on the battery so i get a new at the same time.