98F150/GT

So my 95 mustang has been having some issues lately. It keeps on draining the battery. I just bought a new battery and a newq alternator. If I drive it everyday its fine but last night I had a really long night of work and came out this morning and it was dead again. I have to get this figured out before I can sell the car so any help would be appreciated.

PONY GUY

something is staying on and draining the battery

PRO50SC

Where in Maryland are ya?

98F150/GT

north of carney south of bel air... glen arm its called lol.

98F150/GT

any ideas on how to trace what is staying on?

90GTRagtop

You seem to have what is known as a parasitic drain. The first step to tracing it out is finding out which circuit it's in. Hopefully it is not an intermittent problem so you'll be able to find the circuit on the first pass. The best way to test is using a DC Amp meter. You'll need to put the meter in between the battery post and the battery cable so it can read amps. Do you have an Ammeter and do you know how to use it? If you do, connected it in series with the battery cable and set it at the maximum scale for starers and look at the amps being drawn. It is normal for some amperage to drawn for keep alive memory in the PCM, Radio, etc. However the normal draw should be much less than ½ amp. After you are connected properly, remove the fuses one at a time and check the draw. When the current drops dramatically, you have found the circuit. Now you'll need to see whats on that circuit and start checking the components one by one. If you check all the fuses and that doesn't do it, don't forget to disconnect the fusible links in the same manner.

This can be one of the most tedious analysis to complete, but it's the best way. If the problem is intermittent, it can take a while. One of the most difficult I ever had was long long ago in a galaxy far far away on a '72 Ford LTD. It turned out to be a short in the alternator, but the alternator would charge and would only drain the battery when the armature stopped in just the right spot. After a long time and figuring out what it was, I could see it by turning the alternator slowly by hand. It would drain when it hit the right spot.

Good luck to you...................

Jon D

90GTRagtop is right after reading some of his post he seems to know his **** that is the best way also if you dont have a amp meter when you disconect and reconect the posite terminal if it sparks it usually means something is drawing some power.