New Alternator, Low Output

Subscribe
Dec 17, 2018 | 11:22 AM
  #1  
Hi,

The stock alternator on my 1995 SC400, with 74,500 miles, quit running on a trip, which made for a low tow truck home. I charged the battery overnight, but after starting, my voltmeter read 12.1 V, then started dropping 0.1 V every minute or so. I decided to have a shop perform the replacement, and when I got it back, I noticed it wasn't the 14.5 Volts the other alternator was putting out before it died.

I drove it a couple of hours Saturday, and my digital voltmeter plugged into the cigarette lighter never got over 13.7 V, and at a light, the voltmeter dropped to 11.8 V with the headlights on, the heater fan on high, and rear defogger running. I took it back to the shop, assuming that the alternator is defective.

Any comments? A month ago, the radiator was leaking so bad, I was afraid to drive it very far, even with antifreeze topped off, it was still leaking pretty bad. I guess a 24 year old car, even with low miles, doesn't owe me much.
Reply 0
Dec 28, 2018 | 03:24 AM
  #2  
Quote: Hi,

The stock alternator on my 1995 SC400, with 74,500 miles, quit running on a trip, which made for a low tow truck home. I charged the battery overnight, but after starting, my voltmeter read 12.1 V, then started dropping 0.1 V every minute or so. I decided to have a shop perform the replacement, and when I got it back, I noticed it wasn't the 14.5 Volts the other alternator was putting out before it died.

I drove it a couple of hours Saturday, and my digital voltmeter plugged into the cigarette lighter never got over 13.7 V, and at a light, the voltmeter dropped to 11.8 V with the headlights on, the heater fan on high, and rear defogger running. I took it back to the shop, assuming that the alternator is defective.

Any comments? A month ago, the radiator was leaking so bad, I was afraid to drive it very far, even with antifreeze topped off, it was still leaking pretty bad. I guess a 24 year old car, even with low miles, doesn't owe me much.


I had the same issue. Its not the alternator, but, it is. Advance and or autozone will give you a 100 amp replacement. Its not big enough. Get a 130 amp or higher.
Reply 0
Subscribe