Weird Voltage issues?

[downsouth0]

Hey all, Im having some weird voltage issues in my ride. Its a 95 turbo gsr sedan. First of all I just replaced my 10 month old optima battery that was shot. my alternater is about a year old(alterstart 135amp).Well before I changed my battery I ran 4 gauge wire from +battery to underhood fuse box,then 4 gauge from fuse box to my alternator like alterstart recommended,and it helped alot as far as keeping my voltage up past 13.7 while driving and 12.2-12.5 at idle via my apexi turbo timer. before the wire upgrade it was 13.5 driving and 11.4 at idle. Now out of nowhere my voltage drops to 12.2 when accelerating and driving, then shoots to 13.6 when decelerating(backa$$wards) .what should I be looking for to cure my issue. Sorry for the long post.

[hobie237]

not throwing any codes?

[downsouth0]

none whatsoever

[acuradriva]

Id hook it up to a multimeter to it instead of going by the turbo timer. I don't know how accurate those would be.

[hobie237]

Originally Posted by acuradriva

Id hook it up to a multimeter to it instead of going by the turbo timer. I don't know how accurate those would be.

very good idea

[downsouth0]

sounds like a plan. not to seem like a complete idiot, but where should I hook one up so I can check my voltage while driving and at idle, or should I get a pro to do it?