okay i posted on the electrical board no reply's posted on tbi board no reply's.. so i will try tech board hopefully i get some reply's.. kind of long story and i just copied and pasted from my electrical board post..
Shawn



first to start i dropped a hot wire while putting an auxillary fan to help with cooling.. i figured i burnt some wires since the car wasnt charging. checked and changed fusible links.. changed fuse (near battery) i thought it went to fuel pump or ecm not sure..
exhanged my alternater,got my battery tested. no everything in the car is fine so i believe but the car only runs at 11.5 voltslike the alt isnt turning on or pushing the proper volts..
this is what i posted on the tbi board since i figured this might cause some of the problems.. i have a 91 tbi 305


When i got my new alt i figured i should get a new plug for it as well.. The plug that hooks up at the top.. my old plug had only 2 wires coming out.. a red wire and a black wire. the new one had 3 wires a red wire black wire and a brown wire.. i hooked it back up red to red black to black and left brown out.. brown IS NOT CONNECTED

could this be my problem?? I have done a search and it shows it is needed for the alt to start to charge??
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maybe i should re-explain my problemto help out a little since people are looking but no one is typing..

first there is a red wire that plugs into the junction block near the battery,goes back towards firewall on passenger side and heads towards engine.. i am wondering what this wire is for..

Next to explain my problem with a little more detail..

i was wiring up an auxillary fan to help my car out with cooling as explained above.. the wire i decided to splice to came from my junction block ended up being the red wire further up reason why i say further up because near the junction block wasnt orginal wires.. well as i was wiring the car i dropped my hot wire and watched sparks fly before i reacted quick enough to pull it off.. now i did blow the fuse near my battery that is on the fender what that goes to i have no idea? well i went to start my car cranked right over but my volts arent normal anymore.. i did check my fuseable links,battery at walmart ,alternater by vato zone and checkers... well i had an old alt already so i decided to buy a new one.. with the new one i bought a new connector as well i used to only have a 2 wire connector now it is a 3 wire connector... the wire that doesnt match is brown i have no idea where that goes.. or what else to check on my car..

do you guess think i shorted something out with that red wire??

do you think this new alternater wire could cause some problems??

help i have noidea where else to look...

Shawn

 

I believe the brown wire goes to the internal voltage regulator and is needed for "excitation". If your car came with a 2 wire alt and your new alt is 3 wire, it isn't going to work.