Alternator/electrical Bugs? Please Help

[NikNak]

I have a 2004 lexus is300 sd, 6 cyl auto/techtronic on steering wheel,around 68,000miles. about 8 months ago every time it is moist, damp, rainy, humid my dash lights up with that funny little headlamp self adjusting leveler light comes on. about 1 month ago we started having problems starting the car and when putting the car in drive it doesn't catch. It used to idle fowards on its own at almost 3 mph with out stepping on the gas, now it doesn't move at all. I have to mash the gas to even get it to move a lil above 10 mph. Then it bucks and finally catches after about 60 yards of driving it. We had an alternator test done and the alternator is def. bad it has a doid (?) in it. Are all these issues related??? or is my car just hexed with some serious serious electrical gremlins???? Also does anyone know how hard it is to change out the alternator by yourself, because I am a Do It Yourself'r and would love to save a few hundred bucks if its not too difficult.

[lenore]

I would start with when was the last time the battery was changed? If you have a meter the voltage on the battery should measure around 12.8 volts with the engine off. When the engine is on with the headlights on you should read 13.5 to 14.5 volts across the battery...If you read only battery voltage of 12.8 than your alternator is diffinetly bad. As for changing it it should be easy enough for most diy folks...Look on Rock Auto for a replacement or several of the other sites including Sewell Lexus which gives us a discount. Another is Partgeek.com...Good luck By the way a low voltage condition in the battery could cause many of the indications you had.

[NikNak]

I would start with when was the last time the battery was changed? If you have a meter the voltage on the battery should measure around 12.8 volts with the engine off. When the engine is on with the headlights on you should read 13.5 to 14.5 volts across the battery...If you read only battery voltage of 12.8 than your alternator is diffinetly bad. As for changing it it should be easy enough for most diy folks...Look on Rock Auto for a replacement or several of the other sites including Sewell Lexus which gives us a discount. Another is Partgeek.com...Good luck By the way a low voltage condition in the battery could cause many of the indications you had.

[NikNak]

the battery is an optimum yellow top. battery tested completely fine, alternator tested bad bad bad. it was at 11 volts and below the battery on the other hand when it was tested by itself was measuring above 13. although it has been 3 stereo systems and 5 years later since I replaced the battery. The self adjusting light leveler signal that comes up on dash is only occasional and started way before I had the issue with starting the car. Appreciate the comments this glorified toyota has been nothing but problems since 2 years after buying it. And the parts and labor are sooo darn expensive. I should have thought that one through before I went for a import. Maybe next time I wont be so eager to spend 38k on a knock off toyota supra, and just buy the supra for half that. I should have done my research because I'm finding more and more and more wrong with this lexus is300 when it comes to electrical. What a waste of 38k. I will be sure to check out those sites you posted. And again thank you.