deckind

Ok here is the scoop...we have been having a problem with my GF's 86 gt. It has started to gradually lose power while driving on the freeway to the point of having to pull over and either jump start it repeatedly or tow it to get it home. We were told that more than likely the alternator went so we purchased a 94/95gt alternator and did the 3g conversion on her car. Now this is where the issue comes in. We have wired the new alternator to have the original black and orange wires with ring terminals connected to the alternator as well as a 4 gauge wire from the alternator to the positive side of the battery. The voltage level before starting and after starting while idling are the same and then when you hold rpms the voltage increases. On her car if you pull the negative battery cable the car dies. On my 96 v6 the car continues to run with the battery totally disconnected for about 5 minutes. What is going on with her car? Why won't it at least stay running off of the alternator? Why is the car not charging like it should? It seems almost like the car is running off of the battery and not the alternator.

preciousroy

first, make sure all your fuses and fuseable links are ok, then check the wire that is supposed to turn on the regulator on the alternator, i dont have a wire diagram so i cant tell you which on it is or anything, but you should have pwr going into the alternator from either the ign switch or the pcm that turns it on so it can start charging

SRVirtual

it sounds to me like the alternator is working if it is increasing the volts but when you disconnect the neg cable on the battery if it dies your alternator might not be grounded properly?

deckind

Well considering the alternator has a 4 gauge wire to the battery it should charge a little more I would think and it isn't. All of the fuses are alright that I have seen. How do I test a fusible link to see if it is alright? I will look at the book and see what I can find. The chiltons or haynes should have it right?

deckind

How do I know if the alternator is grounded properly? What does it ground to? I am pretty new at all of this electrical stuff. I am kind of learning as I go along lol.

deckind

ttt-I would like as many suggestions as possible to check tonight when I get home from work.

deckind

ttt-more info still needed

deckind

I added a new ground from block to fender, checked all of the wiring, cleaned all of the grounds, put in a new optima since the other one was bad (that's two), replaced the starter solenoid because the other one rattled, and I checked all of the fuses. I did find that the plug on the back of the alternator was not pushed in all of the way but the voltage does not appear to go up when idling or when at sustained RPMs. We drove it around a little bit last night and the voltage never dropped or anything on the battery. Any ideas of why the voltage is not increasing even at sustained RPMs? Also, any idea how to test the alternator to see if it is getting the signal to start charging?

7upedition

load test the system, you'l need a load tester from napa or some autozones have them for free... you cant get an accurate reading from a dmm...

deckind

Thanks, I will take it by autozone today and have them test it for me.