battery drain
Thread Starter
|
New User
Joined: Aug 2006
Posts: 20
Likes: 0
battery drain
I have an 85 f150 4x4 . if i dont disconnect the battery every night it will be dead by morning. I ve changed the alternator and voltage regulator. with the battery disconnected and checking the draw with a meter ive got a 12 volt draw. i went through and pulled evey fuse while watching the meter and was unable to find the problem. any body have any idea what else to check ??
New User
Joined: Oct 2006
Posts: 4
Likes: 0
Hijacking this thread--but my 84 is doing the same--I get a reading od 12+ volts when I test the ground cable to Neg post on battery--Unplugging all fuses doesn't stop drain--Unplugging the regulator harness makes it stop--I have replaced the regulator but it still did it--I'm wondering if, when the alternator got replaced the wiring got on wrong--Does anyone know what colors go to what terminal?
thanks alot--love the forum
thanks alot--love the forum
Cargo Master
Joined: Apr 2003
Posts: 2,057
Likes: 423
From: Too close to Houston
As Mil1ion implied, testing voltage doesn't really tell us anything about the drain other that that it exists (as it probably should to some degree, for clocks, radio presets, etc.). What is helpful is to know the current drain. Use your VOM on the "amps" scale and check the milliamp drain from the ground cable to the battery post. Make sure the ignition is off, doors are shut, and the underhood light (if equipped) is unplugged for this test.
Cargo Master
Joined: Apr 2003
Posts: 2,057
Likes: 423
From: Too close to Houston
That is a lot. Try pulling fuses one at a time while the ammeter is hooked up. If nothing changes you may have a bad diode in your alternator.
Trending Topics
New User
Joined: Oct 2006
Posts: 4
Likes: 0
--tried that--the only thing that stops the amp drain is unplugging the v/r--I've replaced both the alt and reg twice now---go figure
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Posting Guru
Joined: Jun 2004
Posts: 1,635
Likes: 0
From: Niceville, FL.
Make sure the Orange/Light Blue (O/LB) wire goes from the field (F) terminal of the regulator directly to the field (F) terminal of the alternator. Does the alternator charge the battery at 14 to 16 Volts? With Ignition Switch "OFF" make sure there is no voltage on the stator (S) terminal of the regulator. If there is voltage, find where it's coming from. There may be voltage on one or more of the Ignition Switch "RUN" terminals with Ignition Switch in the "OFF" position due a faulty or misadjusted switch.