battery drain??
Thread Starter
|
New User
Joined: Oct 2004
Posts: 8
Likes: 0
battery drain??
HEy whats up all! i just bought my first truck. im the proud owner of an 88 f-250 2wheel drive with a 4.9L engine. the only problem is i have to jump it every morning and the next day the batt. is dead again! the batt. light does come on with the key to run, but when the engine is actually running it stays off. i have a new battery and a new positive cable running to the starter relay. if i disconnect the batt. and put a multimeter on it ill get like 11.75V but then second i attach the cable it drops to like 9V??? my only theory is that the regulator is shot. but (excuse my ignorance) i cant find it to test it.I know that ford has some external regulator and some built into the alternator. as far as i can tell there is only one plug going into the alternator so im guessing i have the external one, but i cant locate it.
So if anyone can tell me where to find the regulator, that would be great! also if there are any other theories why my batt is draining or what else i should test. im new to this board and would really appreciate the help. thanx alot guys!
So if anyone can tell me where to find the regulator, that would be great! also if there are any other theories why my batt is draining or what else i should test. im new to this board and would really appreciate the help. thanx alot guys!
Posting Guru
Joined: May 2003
Posts: 1,011
Likes: 0
From: South Dakota
Regulator is in the altenator. A rebuilt is around $100 to $200 depending on brand and parts house. If your battery is reading 11.75 check the 'water' so it is up to spec and put a low amp charger on overnight. Make sure all connections are tight and clean.
Post Fiend
Joined: Mar 2002
Posts: 19,402
Likes: 38
From: Bonita Springs FL
You have a a short somewhere in the system. Attach a meter in series with the battery with the truck off. Normally, you'll see a very minute current draw for the computer and the radio. For everything you turn on, you'll see a little more current flow through the system. Start pulling fuses, and when the current drops off, you know what circuit is causing the problem. Then, go buy a haynes manual and start following wires until you find the short. It's a pain, but it's got to be done.
Or, you can just disconnect the negative cable every night.
Or, you can just disconnect the negative cable every night.
Elder User
Joined: Apr 2001
Posts: 772
Likes: 0
From: Glen Burnie Maryland
go out in the morning and put your hand on the alternator casing. If it's WARM and the engine has been off all night and is COLD, then you have a diode in the rectifier pack that is bad and leaking current to the stator coils heating them up.
Overhaul the alternator. Put a new rectifier, brushes, and a voltage regulator in. Use the heatsink grease on the backs of the rectifier and the regulator to help them along. Doing it yourself shouldn't cost any more than $45.00 US (parts) at a reputable generator shop.
Larry
Overhaul the alternator. Put a new rectifier, brushes, and a voltage regulator in. Use the heatsink grease on the backs of the rectifier and the regulator to help them along. Doing it yourself shouldn't cost any more than $45.00 US (parts) at a reputable generator shop.
Larry
