overcharging battery/electrical system
 

i have an 1985 supra that likes to charge at about 17 or 18 volts....this continues when i accelerate...but when i press on the brake...use the windows...or shift it goes back to normal...it also charges normal when im at idle...maybe my voltometer is acting up?..but i dont want to take chances..anyone had this problems...and maybe have some possible solutions or maybe things i should check?

get your alternator checked.... i believe there is an item called a voltage regulator inside it which has decided to take a dive on you

well try that first anyhow :)

funny, my 83 was doing the exact opposite. It would sit at normal without using electronics, but when i used the power windows or pressed the break or stuck the fog lights on or whatever, it would get down to about 10 or 11 from 13 or so. I just took apart my alternator and replaced the voltage regulator about 2 weeks ago (which seemd to have worked), didn't have it tested though I probably should have. I did wierd stuff when i accelerated into high rpms too but i forgot.

ive replaced the alternator 4 times...and nothing still with the same result..so its not that..i dont know maybe any other solutions?

Buy an external voltage regulator and mount it on the fender by the alt and see if that helps..If not then i can just say let a dealer run a diagnostic on the electrical system..

it use to happen on my other 85 mk2 supra... and i check on the fuse on the fuse box... and it runs a bigger fuse so when you acceleration then the battery went up or goes up... and replace by the stock fuse then it solve the problem.... so try to check on the fuse... and see that helps you.