[TWallace]

Good Evening,

I have an 87 ford Mustang and the battery wont stay charged. I took the alternator to get tested and they say its fine. I even took off both terminals while the car was running and car ran barely for a little and finally cut off.. Is this normal ? I thought that the car is suppose to run off of the alternator.. The funny thing is that all this starting happening right after i changed the heater core, which requires taking apart the dash and other related items. Is it possible that a wire is crossing or something that im missing ? Thanks in advance.

Ted

[Till]

Id have the alt re-checked somewhere else...

edit I glanced over your post yeah that could possibly be electrical, but before I would dig into the electrical Id have the alt re-checked

thats just me though

are you 100% you connected everything back and didnt tear out a wire or something

[83 5.0]

Do you have 13-14.5 volts across the battery when running? If not alternator is probably pooched.

If the voltage is good then Have your battery checked also, maybe on it's way out.

Here is a link to a wiring diagram which may help. Mustang FAQ - Engine Information

Good Luck

[Till]

^ I agree but at the same time I dont really trust that method of testing the alt

[wraitherx]

nothing wrong with that method at all. what they do at autoparts stores is to put it on a machine and hook up leads to the output side (positive) going to the battery, hook up a belt to the pulley from their motor, and it measures the voltage being output. same exact method except dont have to take it out of the car