my battery light is coming on but its not consistent, the duration is like a few seconds.i took it to my mechanic and he attached a meter or whatever it is called and i was at 14 something which he said was real good, he told me to turn on the head lights and the meter still was in the green at 14 something.he said the alternator so far is good.however one of the terminals was a lil loose so he tightened it. he also suggested it might be the battery terminals because there really old, so i changed them out and the battery light still came on and then went off when i went to the store. i recently changed my distributor because it was going bad and leaking oil, normally when this happens the alternator can go bad because oil leaks in but it has been 2weeks and nothing. i have HID lights but i haven't had any problems with them...i don't know what to prepare for. what is going on!!??

 

Check ALL of your charging system wiring, not just the battery terminals. Sometimes you can get corrosion especially on the grounds where they contact the body.

 

Alternator starting to fail, bad battery, bad battery cables. Take your pick.

Where did you measure the voltage at?

SC3 or SC4? SC3 = Distributor leaks oil onto alternator, SC4 = PS leaks fluid onto alternator

 

local guy has a meter, uses it everyday

 

Did he measure at the battery or at the alternator?

like Klaus mentioned, check your grounds as well. SC is notorious for crappy ground contacts

 

"charging system wiring", where are some of the locations? "bad battery, bad battery cables" how do i test to see if the cables are bad, the meter was in the green at 14

 

This. When my alternator failed the battery symbol would randomly light up but it was inconsistant. Oil leaks right onto the alternator from the distributor if the o-ring isn't replaced.

 

"88supramki" he measured it at the battery......"HiPSI" it was worse than the o-ring so i changed the whole distributor already.......

 

so thats it?? no more suggestion? wtf

 

is the battery new? If so, your alternator is bad or you have bad connections.

He should have measured at the output of the alternator to determine if it's good or not

 

Follow your wires- you know your alternator provides power and that your battery has to ground out somewhere right? On the Supra the batter grounds out on the driver side frame rail, check there- and again follow your cables.


As a side note, I see you're new here and that's great! You have a large community willing to help out and give free advice. Don't lose patience, or you'll find the pool of those willing to help shrink rapidly.

 

i will keep that in mind, thanks guys

 

hey guys i notice something else, i was driving around and i notice that the "ABS" light came on and that has never happen before. so what do u think???

 

(if it was my car i just take it to bryan and lexus and he fixes it)
since your probabaly a DIY'er
jump the diagnostic terminal e1& t1? something like that.. and pull the codes, see what you get.

Batt light can mean, the voltage goes UP or down too high or too low,
and this can be due to the voltage regulator on the alternator being bad,
it can also happen if your battery's cold cranking amps is too low, and the alternator isnt able to keep up sufficiently with all the demands of the power it needs. after years they dont push the 80 Amps (i think thats what your sc300's are rated at) that they were rated for..
so it can cause intermittant problems dependant on a lot of different factors..

 

correct me if im wrong here, cant u check if the alternator is bad by disconnecting one of the battery terminals wen the car is on. if the car shuts off alternator is bad... if its stays running its fine.

also my old crx was acting stupid, all of a sudden not starting sometimes, weird lights coming on. i just ran an extra 3 gauge wire off battery ground and one off the engine... in other words grounded everything extra and for some dumb reason all the problems went away... mind u it took me like a month to figure this out.