99 Ford Windstar Fuse #9 and 16 blown

forgedbyfire · 06-02-2009, 10:37 AM

Hi! New guy here, but im a long time lurker and appreciator of knowledgable Ford minds here.

I did a thread search and didnt see my problem here so I figured I would post a new thread to ask. I have a 99 Ford Windstar 3.8L. When I started it up yesterday to leave the store it died and wouldnt start back up. The AC control light went out and the headlights wouldnt turn off even with the switch off and the ignition turned fully off. I found the #9 and #16 fuses had blown and they blew again when I replaced them and tried to start it up.

I read in one post on another forum that it might be related to The Brake Pressure Differential Deactivation switch being faulty but it was one unsure post so I wanted to run it by you guys before I go replacing a part I dont need to. Im going to take off the air filter today and check it out.

If you anyone here could provide any ideas or other details I would greatly appreciate it, thank you!

mark v · 06-02-2009, 11:31 AM

Dont know why you want to take the air filter off?

The switch is either on the Master Cylinder or just below it. If it is wet it is leaking and shot.

12Ounce · 06-02-2009, 11:43 AM

I'm assuming you are referring to fuses in the "fuse junction panel" which is near the drivers left foot?

Fuse #9 and #16 both feed sections of the instrument panel/cluster. #9 also feeds the Passive Anti-Theft system (if you have it) and the PCM diode (near battery) ... straaange circuit! #16 also feeds Rear Electronic Module.

So how did you get the headlights off? Since the headlights are normally turned on by a ground signal (they have a constant 12v supply) ... you may be dealing with a damaged harness with various conductors being grounded by error ... blowing fuses and turning on lights. The brake pressure switch could also be the problem ... simply unplug it for now.

forgedbyfire · 06-02-2009, 12:07 PM

Yes I was referring to the fuse junction panel, sorry

I was going to take the air filter off because its in front of the master cylinder where the switch is. Im going to take a look at it as soon as I get home

@12 ounce I unplugged the battery to turn the lights off. Are you saying to unplug the brake pressure switch for now??

12Ounce · 06-02-2009, 03:11 PM

Yes, just to see what the impact is.

forgedbyfire · 06-09-2009, 05:29 PM

I just wanted to say thank you for the suggestions. It was the brake pressure de-activation switch. Simply had to replace it and the fuses. Thanks again!

mark v · 06-09-2009, 05:35 PM

Thank you for posting your results, it will hopefully help another person with the same issues you had.

forgedbyfire · 06-12-2009, 11:54 AM

Seems I spoke to soon. My mother in law just had it die when she turned on the headlights. The same fuses blew again. I had her replace the fuses and turn off the headlights and it started up fine. So what else do yall guys think it could be? The Break Deactivation switch was wet and leaking when I replaced it so it probably was part of the problem. How do I go about the process of elimination to find where in the ciruit the problem is? Im a total n00b when it comes to car electronics.

Thanks again for any help!

mark v · 06-12-2009, 12:16 PM

Stop replacing the fuses till it is repaired, you might start an electrical fire.

Did you clean all the fluid out of the electrical connector on the leaky switch?

forgedbyfire · 06-12-2009, 12:41 PM

Quote:

Originally Posted by mark v

Stop replacing the fuses till it is repaired, you might start an electrical fire.

Will do, I was just trying to get her home.

Quote:

Did you clean all the fluid out of the electrical connector on the leaky switch?

To the best of my ability. I wiped all the fluid/grime off the wires and used the tip of a rag to wipe all the fluid out of the inside of the connector. The connector also had a little stopper on the backside which I removed and cleaned all the fluid there. As far as I know it was dry as possible.