little_haus

Hello,

I have a fuse in my fuse box that (as the mechanic likes to call it) has gone "haywire". When I shut the car off, I have to take this fuse out or else it will completely drain my brand new battery within about 8-9 hours; basically overnight. The fuse has a 20 on it, so it's a pretty big one. This problem seemed to be happening right after I got the new battery, but now I'm thinking that the old battery was still good, and that it was just the fuse that was causing it to drain. The other day (before I knew of this problem) I let the car sit for two days and when I came out to start it, it didn't even try to turn over or start; nothing. I then asked a buddy to jump the car, and it was so dead that the car wouldn't start no matter what. This fuse controls the wipers, dome light, door lock acuators, blinkers, speakers, and I'm sure other important things I need. Has anyone ever heard of a problem like this before or knows about a recall that Ford issued on this part? The mechanic said he hadn't seen issues like this very ofton and that I should just take it to the dealer and have them look at it. Any help/comments are greatly appreciated. Thanks!

FoxGT

Do you have a volt/ohm meter?

stevednmc

It seems to me you have a power drain in one of those systems, perhaps even a short. Anything not working or working erratically in any of those systems? It could be something as small as a blown light bulb in your dome light, or as large as a short in your wiper motor.. you need to find a schematic and start chasin it down..

jesse1125

It's not the fuse. You have a short in one of the systems that is protected by the fuse. Removing the fuse opens up the circuit and stops the power from going to the item that is shorting out to ground and completing the circuit.

You need to figure out what is causing the short. It's not the fuse, fuses don't cause shorts.

little_haus

Ok thanks a lot I appreciate it.

No, I do not have a vold/ohm meter.

I'm not very handy at wiring/electrical problems, so I wouldn't know where to start on figuring out what's causing the short.

So the only thing I can think of that doesn't work properly is the motor that causes the windshield wiper fluid to spray out onto the windsheild. It doesn't do anything when I push in on the turn signal lever like it should, other than the wipers coming on for a couple of seconds. Should I take this into a Ford Dealership and have them look at it? The mecanic I went to basically refused to work on it so...

petrock

I would find a different mechanic. This is a standard parasitic power drain issue. Thats electronics diagnostics 101. If your mechanic can't figure it out, or isn't willing to then I'd find a better mechanic who has a clue about electronics. You don't necessarily need to take it to a dealer. Take it to someone who is good with electronics. It should not be too hard to figure out, especially since you have already isolated which circuit is causing the power drain (by finding the fuse for that circuit).

Good luck...

ttocs

x2 - troubleshooting electrical problems can be a pia but it is not rocket surgery. As said above something is not shutting off correctly or else is just drawing too much power. We need to know exactly which fuse it is IE-what accesories it powers- to be able to help and the size and color isn't going to help us. Once we know what fuse it is we can see what it is hooked up too and then by simply disconnecting them to test we can find out exactly what piece needs replacement or repair. Get out your manual and see which fuse it is that you are pulling and then we can narrow it down further.

Stevo86

Easiest way to narrow this problem down is to find out what exactly is on that circuit. After that get a cheap volt/ohm meter and with the car off measure the amount of voltage present on the ground side of the battery circuit. Then simply unplug the pieces powered by that fuse one at a time. Once voltage on the ground side goes back to zero you have found your culprit. It's rare to have an actual wiring issue so long as the vehicles wiring has not been modified. If you have had interior work done lately ensure the fixtures were put in their correct spot. Some parts will fit from left to right but when installed backwards will change the way current flows. On a side note I'm a tad rusty on my electrical diag since I haven't been in a shop for a few years so if someone finds my advice incorrect please let me know. I would hate to waste someones time with bad info.

petrock

I think you mean amps, not volts.

Here is a very good step by step guide to finding parasitic battery drains like this. http://www.wikihow.com/Find-a-Parasitic-Battery-Drain.
Since you already know which fuse, and therefor which circuit, the problem is on you don't need to pull fuses. Skip to relays on that circuit & other electrical components on that circuit. A circuit diagram makes figuring out what is on the circuit alot easier.


Correct, but replace volts with amps.


If by wiring issue you mean something wired incorrectly, that is true. However, if you mean a broken/shorted/damaged wire, then I would say that is incorrect. It is quite common for issues like this being a shorted wire.


Current will always flow from power to ground. Putting a bulb in backwards will not change that. Only components I'm aware of that work with reversed polarity are electrical motors like the window regulator motor, but that is because the circuit & the motor are designed to work that way.
However, it is a good suggestion to take a look at any work that was done around the time the problem started. A pinched/frayed/damaged wire could cause a short which can drain a battery pretty quick.

Stevo86

Volts to amps yes my mistake however installing components backwards happens. I have had firsthand experience fixing a navigator that had it's overhead lights installed backwards and it caused all kinds of issues. Lights turned on at the wrong time some didn't turn on at all etc. Took 8 hours of staring at a wiring diagram to figure it out. Also in my experience if the car is relatively unmodified I have rarely found actual cut or frayed wires. In my experience unless someone starts messing with them they stay in the factory harness and don't just chop themselves up though. But I suppose that's just a matter of opinion.