I have a 1994 EJ1 with a B18C5 swap, for years its very reliable and track raced/daily driver.
Has a P30 ECU with a Tunerview II dash unit.

The other day I installed some 85A Nolathane mounts which shakes EVERYTHING in the car badly. I was actually worried about the electronics it shakes that bad.

Anyhow it seems my assumptions maybe correct as 3 days after Innovative mount install, my system voltage started fluctuating and unstable, plus I notice slight speedo twitches at constant speed.

No codes, no dash lights but I think I have detected a problem.

Voltage usually is rock solid at 14.8-15.2v and doesn't change, unless ELD comes in then its rock solid 13v

now it changes from 14.7 to 15.8 rapidly, when ELD comes in it goes 12.8v-13.5v rapidly. Also holding contant speed i notice slight twitches in the speedo. Car doesn't feel QUITE as smooth to drive (unless thats a placebo?)

Anyhow, whats the chances of the regulator crapping out JUST as I install the mounts.

Or do you think its a ground, loose harness plugs, loose fuse etc.

My car is keept in top condition so I doubt its a ground, but a cable or fuse could be loose from 3 days of this CRAZY shaking from 85A mounts.
Last night I started it and it was solid 15v for a short drive (cold engine I guess) then problems came back.

So either Alternator
Or loose connection

haven't started looking yet so ideas people

 

bet alt took a crap,

take the alt out to a oreillys to bench test it

 

Yeh probably did, however its just a little coincidental that it happened after 3 days of intense vibration from innovative mounts.

I'll check cables and connections first, then get it bench tested. I have read some many times people get them tested and they come out ok. But still give the problem. Even thought it IS actually the alternator all along.

 

yeah i had some unusually problems in the past. i changed out vacuum lines & my cps went bad right after i did it & i never touched n it went bad lol

youll find it out

 

Unsettled the balance of "chi'" within the car eh

 

Checked all the plugs I could find, (doubt its this just from vibration from mounts)
checked all earths. Checked fuses (won't be blowns no shorts)
hmm maybe alternator is starting to play up.

its not mega high voltge, like 14.8-15.5-15.6 max. But its the fluctuating thats going crazy, lights don't dim or anything though.

Im sure the voltage didn't used to do this. Hmmm maybe take alternator out and test