pete88gt

Hey all, yesterday I replaced my voltage regulator. I assumed that I had a stock alternator in my '88 gt, but I replaced the regulator with a "stock" motorcraft unit from O'Reilly's and now my batter light comes on. How do I figure out for sure what amp my alternator is? I can't find any markings or labels at all. I want to make sure the reg amps match the alternators amps. Thanks

7 UP Mustang

Usually the AMPS rating is stamped on the Alternator, maybe where you cannot see it. Question is why did you change out the voltage regulator? I would say that the voltage regulator regulates volts, and is not concerned that much about the Amps out of the alternator. What is the voltage output with the car running? Good luck and I hope you find your problem!
Larry

pete88gt

well after having done some research now here's what I've come up with. I do have underdrive pulleys and a fairly sizeable sound system with 2 10's so maybe those things are affecting the charging system adversly. I keep having surging idle issues in the mornings when I go to start my car with my blower motor running. the aftermarket volt gage i've got drops to about 10volts, and my idle jumps about 100-150rpm, my headlights and gage lighting accordingly dim as well. i assumed just old wiring for these issues because it only happens when the blower is on. well, I was out in my car at work for about 12hrs total where i would start the car and let it run for about 30min with the heater on at idle, then shut it off. i would repeat this about every 3 hrs to warm the inside of the car back up again. the last time i did this my volt gage read about 7 volts and without thinking about it, I shut the engine off...it did not start back up without letting the battery charge up for about 10min with jumper cables....will i have to take out the alternator to find a part # or some type of identifying mark??

7 UP Mustang

Sounds like the under drive pulleys maybe causing this problem. The alternator is not spinning fast enough to keep up with the extra load you have. Can you use a mirror to see the bottom side of the alternator or where ever you are having trouble finding the AMPS stamp? Look for something like 100 A. Good luck.
Larry

lxman1

Usually the alternator fails before the regulator. You need to pull the alternator off and have it tested.

Bubba 95SN

Unplug connector at regulator. Jumper the A to F terminal this will full field alterntor. Should be putting out its maximum.

AdderMk2

do the 3G conversion. that should eliminate your problems