95 gt Electric problems while running?

[stangman1995gt]

This might be a stupid question but we'll see. Mustang started acting up the other day. Wife took it to pay some bills. Was in a store for 10 minutes came out and mustang was dead. Got a jump and we drove it home; made it about 15 minutes down the road and car completely died. Everything went dead in the car that was run by electricity. Car shut off due to not enough spark. I took the alternator out and had it tested at advance auto they said it was good and probably was battery. I took the battery in and they said that was fine. I charged the battery and tried it again and slowly I watched the voltage go down.


What could it be? The alternator is the only thing I can think of. Maybe a fuse?


Thanks Guys!!!


Jon

 

[ttocs]

Charge the battery and then do NOT hook it up to the car for a few hrs and see fi the voltage drops. I had the same problem in mine years ago and the battery tested fine but the guy told me to leave it with him for a couple of hours and he would test it again. 3 hrs later the batter was down to 10v.

 

[stangman1995gt]

Okay I will try that. I just disconnected the battery while it was running and it stayed running the whole time I had the battery disconnected.

 

[CC'S95GT]

Please don't do that old school method of testing the alternator anymore,
Modern cars have computers that need a solid and consistent voltage to them. You could damage the computer.

Inside of the battery the plates could be shorting out. It may test good initially but over time the battery will discharge.

as far as the Alt. you might want to have it tested again (or someplace else) only this time have them load test it 2 or 3 times to get the alt. good and hot. Sometime the electronics inside are fine when it's cold but will show problems when hot.

 

[RichV]

My alternator shorted to ground last year. A fully charged battery got me about 15-20 minutes of running before it started running funky.

You could try and do the opposite, charge the battery, disconnect the alternator, and see what it does. When I bought my 94 it had a alternator that 'tested' good at the part store, but my charging system was not fully restored until I bought a reman'd one. And this was before running pulleys for you guys ready to jump my shit.

 

[ttocs]

my money is on the battery.

 

[toyman]

^^ I'm with you or something drawing a lot of current.

 

[stangman1995gt]

If it was the battery and it was slowly loosing power, shouldn't it be dead after 24 hours of NOT running? It fired right up after not running for more then 24 hours.

 

[Quarter Horse]

Maybe your Voltage Regulator is going Screwy once the alternator heats up?? I think your gonna have to start somewhere and break down and replace one or both..... I'd start with the alternator 1st.