As far as I know, what you're seeing is the load on the battery as the turn signal relay opens and closes...or in the case of the window, with the motor putting a load on the the electrical system.
Unfortunately the stock alternator in the MkII does suck...however several people on the forum have upgraded to a higher amperage unit that will keep up with head lights, fog lights, windows, A/C blower, stereo etc.
Try doing a search on the forum for alternator info. That's my next mechanical upgrade...I don't want to go through another winter with that crappy stock alternator under the hood.
i hate to say it but all supras i think do that. mines been doing that since i got it, my roomate just bought a supra and it do's it also. i just did the alternator swap from the 7m on to my 5m and i think nothing has change. And i'm pretty sure the alternator is good so i really dont know what to say. i wanted to buy a after market gauge also, (volt) but it would just make me unhappy to see it tick all the time.
what exactly is the problem though? Your gauge moving when you think it shouldn't be? Every stock mk2 I've ever driven has done this, it does not cause any ill side effects. Its simply reflecting the electrical drain on the system. Maybe it would be less noticiable with a better alternator but its not doing any harm. No offense to anyone but this is why manufactures use dummy guages (on or off) or skimp on adding extra guages that we may consider necesary. Real guages show real conditions. Conditions that may not make sense to the average consumer in every situation and lead to lots of complaints and questions for the dealers. Your car is fine man, don't worry about it :wink:
yeh! but run your hi beams, rear defroster, and heater blower on hi
simultaneously to fry your alternator quickly. i avoid using rear
defroster for longer life, both mine and the alt's. and staying away
from hi beam/hi blower is a good idea too. mk4 alt will do the job.
this happens with almost any vehicle. My Durango does this, and it has a 135amp alternator. It happens in my truck, and I have a 120 amp Mean Green alternator in there. It also happens on my friend's new Volvo A6. All it's doing is showing you the load of your equipment.
If you don't want to see this happen, just install a stiffening cap in you the supra, it'll go away...