When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
A couple months ago i posted about alternators as in heat 100 degrees my DIC reads 12.9-13 vs a cool night or winter 13.7-13.8. When it read 13.7 it read 14.3 at the fuses.
Today when i went out for a small trip to the gas station it read 12.9-13 so i checked with a good battery tester and the alternator reads around 14 volts at the battery. So i take it the DIC reads about 1 volt low. Has anyone had a charging system light or "low voltage" code pop up when the alternator went bad just curious? Classic cars had a battery and oil pressure light that would flicker a red dimmer at idol on certain vehicles mostly ford late 60s.
The alternator regulates the voltage at the battery so if you read 14 volts at the battery that's OK. I believe that the GM alternators are temperature compensated. So you will see different voltages when the temps change.
Yes i think its the 99 stock alternator when i got the car the decoupler pulley was shot no grease and made a marbling crackling sound so i replaced it with a continental at nights or during the winter last fall to march it would read 13.7 on start up or low 13s after hour long trips. With the summer temps being 90-100+ degrees i noticed it goes to 12.9 sometimes 12.8 when sitting at the bank drive thru or hour trips across town. Never threw any low voltage codes so i guess even with a 12.8 DIC reading with the car running is still mid 13 volts showing the alternator is functioning correctly.
Since the voltage is good at the battery one thing that may be a problem is your ignition switch. The DIC voltage is after the switch so you may be seeing a voltage drop caused by high contact resistance in the switch.
Since the voltage is good at the battery one thing that may be a problem is your ignition switch. The DIC voltage is after the switch so you may be seeing a voltage drop caused by high contact resistance in the switch.
Is that going to pose any problems? So when the gauge is reading 12.8-13 volts in 100 degree temps its actually 13.9-14 volts at the battery when running. No dash lights or codes pop up for charging system. Just seeing it read 12.8 made me think the alternator was weak or dying and simply reading the 12.5-12.7 battery volts when i was waiting at the bank drive thru. It is the original 99 alternator but i guess if its reading 14 volts at the battery then its no problem. Its usually 14.3 at the engine fuses or possibly 14.5 volts at the battery i didnt check during the winter/fall/ before spring or 100 degree weather temps.
So it shouldnt be any issue. One thing i did notice when in the city stop n go traffic 107 degrees the car gets up to 208 degrees not sure if it would get any hotter with the fans set to come on at 201. I should have put a 160 thermostat last year as it takes temps for the the thermostat to fully open maybe 170+? But i just changed it last year and 20$+ in antifreeze i dont want to change it anytime soon. I still have to change to HVAC actuator blend doors which from what i seen cant be replaced unless the dash is removed. What a real pain.
volt reading at DIC and battery
