[The Mustang Kid]

I have had a lot of good suggestions for my problem and I have tried all of them, but have had no luck. For those who haven't read my previous posts, My '87 Mustang has a mysterious electrical problem. Just today I replaced the ignition switch, and the fuel pump relay- two of the suggestions- and jump started it. It ran fine. I drove around town for 20 minutes then shut it off. I went back two hours later and turned the key, and dome light went off, gauges went dead, and "clicked" like the battery was dead again! I would be very greatful for any more advice or suggestions.

[DBT4220]

idk about the relays deal. but what it sounds like to me. (ive had this prob) is you have a bad connection on your ground somewhere. where ever your negative cable is grounded to on your battery. try cleaning and see if this works?

[The Mustang Kid]

Ok, thanks! I'll try that.

[ford-a-natic]

If the rectifier board on your alternator is faulty, it will drain your battery, and eventually shut you down,disconnect your negative pole, check with your ignition off and anything else that draw voltage and touch you ground pole back to your battery if there is a considerable spark, then theres something is drawing voltage, it could be a bad diode in the rectifier board or some thing else that is sapping your battery.

[evintho]

It's a connection issue. To fix it, pull your battery, alternator, starter cable and both battery cables. Really not difficult to do! Take the alt to Kragen or Autozone and have them test it. It's probably alright. Take the batt into a shop and have them test it. If it's good, have them put a slow charge on it to get it to where it needs to be. After removing all 3 cables, clean them really well and take a wire wheel to the cable ends. Check along the lengths of each cable for any missing insulation. If any is found, the cable could be grounding against the frame/block/etc. Replace as necessary. That's probably overkill but I guarantee you'll fix the problem and as a side benefit, you'll have a restored charging system that you'll never have to worry about again! Good luck!

[J. Rhapsody]

ITs easier to just replace the cables if they look bad on the ends. I dont know about you but my negative cable is made of two and grounds to the engine block. Easiest or atleast cheapest way to clean off batter terminals is to pour coke or pepsi on them whipe them off reall good and put petroleum jelly on them.