I intsall a new alternator and battery on my 1988 Toyota Camry (3sfe) with 230k miles. Everything worked and was charging at 14.2-14.3 volts well let it idle for 30 minutes.
After, turning off the car for 1hour and was installing my aftermarket back in.
I turn the car back on and the brake,charge and light turn on. Now when i turn something on like the headlights or when the cooling fans turn on ,the voltage goes down to 13.2-13-4 volts.after they turn off the voltage slowly goes back up to 14.1-14.2volts
what can cause this problem a bad sensor or wiring problem or ecu?
First thing I'd do is get the "new" alt load tested. New parts are sometimes bad but I think most here will tell you, rebuild alternators are at the top of the list.
The Alternator was tested and load test was good, They couldn't give me a replacment because it good.
I am familiar with your pain here and seen the exact thing many times. However, based on what you said, "the voltage goes down to 13.2-13-4 volts after they turn off the voltage slowly goes back up to 14.1-14.2volts".
Only thing that would be causing this is an insufficient charge in battery or the alt isn't putting out enough current to properly charge it while also suppling ALL the current needed to run the car systems. Assuming all connections are verified good of course. I'll take a look at the schem in a bit to see other possible things (of course there always are) but from experience, what I said is the issue and resolution that fixes it for me 99%+ of the time. And am I correct assuming it was a rebuilt (from Mexico likely) one installed? Why I just won't install them anymore and respectfully decline to folks.
yes, it was rebulit in Mexico and it was warranty replacement from o'reilly
holy smokes that car is a 1/3 of a century old. There's probably bad ground connections everywhere.
where exactly are you measuring these voltages?
i am checking the voltage directly from the battery with a voltimeter
I checked all of the grounds and clean them already.
ok here's an idea. Connect your Camry to another car with some short, heavy gauge booster cables. Run the other car. Don't start the Camry but put the key in accessory position. Now turn on lights etc. and measure the voltage.
The battery doesn't drain because every morning i check it and it has 12.7 volts.
Something is causing the alternator not to keep charge at 14.1-14.3.
I didn't say it's draining.
by hooking up another car, you are taking your new alternator out of the equation.
The charging system still works because the battery still gets charge. Right now, i turn on the car and the charge, brake and light turn on when i turn on the car at cold start.
When i install the new alternator and battery during the day, everything was working perfectly. But once I install my aftermarket radio back, i got the brake and charge and light on .
I guess your radio is faulty then.
I install that aftermarket radio to my other toyota camry 1991 and it works there without any problems.
I will try to disconnect the battery and reset everything, and will see if it still comes back. I will do it without the aftermarket radio
I thing , i forgot to mention, when give the car throttle the car goes up n voltage
the faster the alternator spins , the more current it can produce. So that tells me that at idle, it is not producing enough power to meet the demands of the car. I'm still not sure whether your car is demanding too much, or the alternator is producing too little.
Maybe the alternator is producing to little
But ecu decides that option
Once a cooling fan turns on the voltage goes from 14.1-14.2 to 13.2-13.3 but once it the cooling fans turns off the voltages slowly goes back to 14.1-14.2 volts
yes, when the demand exceeds production the voltage will sag.
Tomorrow, i will do some more troubleshooting.