I am having period electrical problems that seem to relate to low output. I just replaced the battery which was leaking. When I checked the new battery after a few weeks with car off it was 12.3 volts and with car on 12.6 volts. I thought it should be 13+ volts. Can you confirm and also if so would it be alternator or voltage regulator. Any suggestions. thank. Bob.

Mine ('96) runs at 14.2V with the engine on, 12.7 off.
I'd say something is wrong. Have you pulled the Alternator fuse out of the underhood fuse panel and checked it? (it will chek "good" with an ohmeter, even if it's bad (regulator loop)that's why you pull it out.

is the small plug on the alternator broken or loose?

Try this, I may have more suggestions, I'll post them later, but most of the time, it's the alternator when it's not something simple...

Slantsixness

Mine ('96) runs at 14.2V with the engine on, 12.7 off.
I'd say something is wrong. Have you pulled the Alternator fuse out of the underhood fuse panel and checked it? (it will chek "good" with an ohmeter, even if it's bad (regulator loop)that's why you pull it out.

is the small plug on the alternator broken or loose?

Try this, I may have more suggestions, I'll post them later, but most of the time, it's the alternator when it's not something simple...

Slantsixness

Can you advise which fuse the "alternator fuse" is. I looked in the owner's manual and no underhood fuse listed as alternator. thanks

I'd double check your vlotage readings at the battery terminals with a good volt meter. Don't trust the dash gauge.
The voltage regulation duties are given to the PCM. Thay rarely fail.
Under the hood you will find a black box with removable lid, the fuse will be in there if it has an alternator fuse.