bow2000SI
New Member
I recently picked up a 2000 civic SI. It has a 550CA OPTIMA batt. and a 165amp alternator which are both fairly new. the starter was also replaced recently. Most of the time, the alternator charges as it should, and I recieve between 13.6-14.2 volts to the dash, and to the battery posts, along with all other hot wires at both ends. I have been having problems with this voltage dropping off, to as low as 11.9 volts at the battery. I know what your thinking... alternator, however this problem has been persisting for about 2 weeks and when it is low, it doesn't seem to suck the charge out of the battery, so I'm led to believe some recharging is still taking place. without any rhyme or reason, the voltage will increase to normal. there is no relationship with this problem linked to the air conditioning, stereo system nor any cooling fans. the biggest problem is when the voltage reaches it's peak low, ( less than 12.5 volts) if I shut the car down, it takes quite some time to restart, and even if it is jump started or charged, still takes 25 or more minutes. it has only happened twice, however seems to not be improving by any stretch. my assumption is; a thermocoupler in voltage regulator, or an overheating diode, or ?? help me out folks whose seen this before?