Okay a few questions for everyone. Sorry for long post, but want to give as much info so you have all needed to reply. (hopefully)
Car is a 2005 Camry XLE 2.4L. Factory alternator is 100amp unit 4 wire plug with S, IG, M, L wires in it and the battery stud of course as well. Battery is Toyota 24r, eye green, 582 amps with 125 min reserve.
Tests done with two Vohm to check accuracy/validity. One meter is a very expensive one I got ages ago from Radio Shack that is still going strong and the other is a TPI440 with scope.
Has a charging issue I'd like to improve level of.
Used Vohm to test battery. Keeps a 12.5 to 12.9 rest voltage. Run bright lamps with engine off and voltage drops to about 12.2 or just a bit under with the lamps on for a few minutes watching it slowly drop. Turn off lamps and voltage climbs and recovers again at 12.5 or smidge higher range. Battery starts car fine and current draw drops voltage at battery to 9.xx (sorry did not note .xx numbers) and then recovers fine. Terminals cleaned with clean connectors. While generally cleaning up stuff I removed the battery and did notice that the short sides were very slightly bulged.
Big three done with knu copper 4 g. Added grounds go to bolt on engine and factory bolt on fenderwell. Fused 4 g from alternator stud (added to existing wire) to bat +.
So, issue. Factory alternator was charging at 13.4 or so volts at idle. With load of high beams and AC on max it dropped into the 12.4 to 12.6 range.
I have an aftermarket audio system that puts out just at 1000 watts. Have gains set with scope so that max unclipped output is reached. Watts are calculated by unclipped voltage output at amps to get the 1000 total.
Turning the audio system on with bass heavy music (slowed down Bass I Love you) the charge rate drops (again at idle) with other loads still on to the 12.1 range and may have decreased lower than that, but did not continue to run to see. Was below battery voltage at rest so felt draw was getting into battery power as alternator amps were not keeping up with it.
I am used to every car I've ever owned (and that has been many) charging at idle with no load at 14.4 or so. With load drop may drop to say 14.1 to 13.9 range.
Started looking for a new alternator and if I was going to change it I may as well add a little amp capacity to it. Don't have the huge money for these "high output" alternators (saw many at $300 to even $600 range!) and was worried by the slightly lower cost ones as read a number of posts about some being cheap rewinds that actually loose output at idle and people having problems with the charge light coming on etc.
Anyway, put the scare into me so looked at factory alternatives. Found that the same year Highlander with a tow package came with an identical alternator to mine in 130 amp. Ordered one and just installed it.
Now voltage range at idle is 13.8 without load. Tested everything and still keeps in the charge range (over battery rest voltage with full load on).
Here is my wish/hope and where I need help.
I know the output is okay and can be called "good enough", but I have to wonder about the lack of 14.4 no load charging and would prefer that the charge rate was at that level instead of what I'm getting.
I've read that some vehicles have a computer controlled charge rate as well as an internal voltage reg. I know the alternator has an internal voltage reg, but does the 2005 have a computer control to adjust output? Just wondering if there are systems on the car that the computer limits the voltage to 13.8 for some reason.
Just strange that both alternators are charging roughly in the same range at no load idle.
Any thoughts on battery? I'm only wondering as unsure how (if it has it) a computer controlled output works. My Haynes shows the incorrect wiring diagram (does not have the "M" wire) and the only other one I have is the online download 2002 manual which has the old type alternator as well. Wondering if battery has an issue that has not come up in general use yet and is somehow causing the 13.xx rates.
I'm going to have it tested when I take the core in on the alt, but wondering anyway.
Any other suggestions, common issues, TSB's that cover this issue that might help get the rate up?
Really just an issue with me I guess, but would much rather have 14.xx volts going so systems did not have to work so hard.
Any help appreciated
2005 Camry 2.4 xle alternator
Linear Mode
