2004 Mystery Drain On Battery | Ford Thunderbird forum club group 1955-2005 models
  • We're glad you found us via a search engine! Right now, you can join our club absolutely free and unlock member only features like the site search! This notice only appears once! It only takes 30 seconds to register, and we would love to have you as part of the World's largest Thunderbird Forum/Club! Click here to continue

  • Click here to remove google ads from the site
  • Click " Like/Thanks" at the bottom of a member's post to reward and thank them for their response! Points are added to their profile.
  • 2002-05 Owners. As of August 2022 there is now an entire suspension kit for sale! Scroll down to the bottom of the first post click here.

  • Get rid of swirls and minor paint surface scratches with this Polish & Compounds kit. Click here to read more!.

2004 Mystery Drain On Battery

  • Thread starter Thread starter SilverBirdy
  • Start date Start date
S

SilverBirdy

Click here to upgrade
Reaction score
4
Thunderbird Year
2004
Something is drawing from the battery on my 2004. My mechanic has tried everything he can think of, including changing the battery several times, checking the battery draw, cleaning all contact points. According to him, there is something that is draining the battery, but he cannot find what it is. The battery will die after sitting anytime between four and 10 days after charging and giving it a good run. Does anybody have any ideas? Any help would be appreciated.

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 
Disconnect the ground wire from the battery. Hook a multimeter between the cable and the post. Set on 20 amps and work downward, until you see how many amps you're actually drawing. Then pull one fuse at a time until the meter reads zero, and that is the circuit that is going to ground. Checking everything on that circuit.
 
2 years ago when I purchased mine from a Ford dealer, I found battery running down in about 30 hours

It turned out that the REM (rear electrical module) was defective and causing a very large draw / drain with car turned off

I was lucky that dealer had 30 day warranty so they took care of it - it is quite expensive

Possibly the front module could also cause this?
 
My mechanic did that, and he still couldn't find what the problem is. He's spent well over a month trying to find the source-this time. It's been a continual problem since I bought it three years ago. It only has 36,000 miles on it, and I don't want to sell it. My first 2004 never had a problem. This one, my second 2004, has constantly had a battery drain problem. The car has been thoroughly checked by both the local Ford dealership and my independent mechanic. Neither can find the source of the problem.
 
2 years ago when I purchased mine from a Ford dealer, I found battery running down in about 30 hours

It turned out that the REM (rear electrical module) was defective and causing a very large draw / drain with car turned off

I was lucky that dealer had 30 day warranty so they took care of it - it is quite expensive

Possibly the front module could also cause this?
 
It is the law of electricity - if a "good" battery is going down there IS a current flow. May have to use a milliammeter to find it, but it is there. If your clock works it is pulling a small current. Perhaps the radio also. Maybe the computers. Those are usual and normal. There has to be another fault. Good luck.
 
Used the multimeter suggestion and found my discharge was the Radio Amp, pulling about 2.57a when keys out of the ignition. pulled the amp out, radio still works, but battery has lasted 5 days when not driving the car.. just FYI,, looking to find a new 6 disc changer and an amp...
 
Back
Top