Originally Posted by tbaxleyjr
most of those circuits are 12V.
You are right on the money on check and verify before buying parts. - an initial check of the electrical system is see if the battery approx 12.5V. If not, it needs to be charged before doing much else. with engine on should read 13.5 - 15V both w/o major loads and with lights and AC on. Much deviation (1/2 V) would indicate a possible bad voltage regulator.
OK it died after work last night. As I was waiting to turn a corner. I got nothing at all, just clicks when I tried to turn it over. Once it was pushed into a parking lot, I read the battery and it was like ~11.1 or so. I got a jump to start it and read the voltage from the alternator and it was now 11.4v - down from the 11.9v it was before. So I removed it and had AutoZone bench test it twice, both times it was no good. Bought a new one and installed today, along with a freshly charged battery. I also changed both terminals at the battery (they were pretty corroded). One I trimmed back because the corrosion had started down the stranded copper line. Started it up and I drove it home. As I pull into my driveway...It stalled!
I recheck the alternator (at 2k RPM's A/C on) and it is reading 14.5v. Beautiful right? At the battery I get (same 2k RPM's A/C on) the same 14.5v.
I am now noticing that the battery, brake and the A/T lights are much dimmer than the oil, check engine and other lights when the key is in the "on" position. I have checked the fuses and all are good. I even pulled the 100A fuse that is screwed into place. Do I need to reset the computer?
So, a recap:
1. Replaced dead battery
2. Repalced fuel filter
3. Replaced low output alternator
4. Replaced both battery terminals