vidit10

I have a 2009 v6 convertible and I have been experiencing electrical problems for past few weeks. I am hoping someone can help me with it. I am putting the events in chronological order
- First the wipers started going crazy, they would start and stop by themselves.
- The next day wiper fluid started gushing by itself. At this time, I took the fuse #10 from under-hood fuse panel out so that the motor doesn't burn. I thought it wiper switch has gone bad, so I ordered a new one.
- While I was waiting for the switch to deliver, fuse 3 in passenger compartment fuse panel blew up. I replaced it and as soon as I turned the blower on, it blew up again.
- Changed the wiper switch, replaced both the fuses, but this time tried running wiper before blower - fuse stayed intact but wipers did not run. (earlier they were running by themselves, now they don't run at all). Turned the blower on and the fuse #3 blew up again

This whole time the battery has been draining slowly, and if I don't start the car for 3-4 days, I have to jump it. Also, in the beginning I could hear water gushing in the driver side door, or the panel below the door. I don't hear it anymore, but I often see droplets inside the car near the driver door.

All these things make me believe that I had a water leak and there is a short somewhere (albeit not a full short - otherwise battery won't last 3 days). I can see the weather seal on windshield coming off at certain points. The question is how do I diagnose where the short could be?

I have seen people suggesting putting a dehumidifier in the car overnight and it will take care of some problems - is that worth a try for electrical shorts? I just don't know where to start. I would appreciate any and every help. Also, though I have spent some time working on my mustang, never done any electrical work (except replacing a starter, if you can call that electrical work) and never opened the dash - so please link steps if you can

Thank you!

Buckshot Barry

Check for dampness in the passenger floorboard along the right kick panel below the Smart Junction Box

I use a blue shop paper towel that turns colors when wet.

vidit10

Thanks for the response. I checked and SJB doesn't look damp, neither does the passenger floor.
Sorry for the delayed response, I had to leave the car at work over the weekend because of rain.

Buckshot Barry

Are you the original owner and has there been any internal wiring modifications?

Do all the rear lights work correctly, i.e. brake, blinker, etc?

vidit10

I am the original owner. No change in wiring.
I didn't notice any problems with lights, but I will double check tonight and confirm

vidit10

All the lights are working except for one rear passenger side marker light. I am not sure how long it has been out for.

Buckshot Barry

Consider replacing or swapping that bulb. If it doesn't start working, from what I've read over the last 12 years is a Smart Junction Box issue.

Maybe even just aged corrosion.

JJHoover

is there anything wet inside the car and if so where is it?

vidit10

Last weekend I put an industrial dehumidifier in the car for ~48 hours and blower started working, but the wipers are still not working.
I also swapped the bulb on side light (after dehumidifier) and it is working.

There were no wet spots in the car, but that could be because of dehumidifier. But, it snowed here in DC yesterday and I left the car out in open. There was about 5-6 inches of slushy snow and I checked for wet spots this morning. Still did not find any. Blower is still working.

About 6-8 weeks ago I could hear water in the driver side door (or the door sill). So there was definitely water leak at one point. I don't hear it anymore.

vidit10

So I took out the SJB, opened it up and it did not have any corrosion (or water) inside, but one of the connector next to it (mounted big white connector) had some corrosion in it. I cleaned it a bit and put some WD-40 on it.

But, I was thinking if SJB or that connector was the issue, why would only wipers be affected and why would both washer and wiper motor start having issues at the same time. I looked at the wiring diagram and it seems only connection between SJB and wipers is that 10A fuse (Fuse 3). I checked voltage on it and it seems to be fine.

In the wiring diagram (attached) everything, including the washer motor, seems to be controlled by "electronics" inside the windshield wiper motor. If this "electronics" is bad wouldn't that explain all the issues occurring simultaneously.in wipers system and only in wipers system. Does that make sense? Shouldn't I be looking into this "electronics"? I also read somewhere there is an "internal governor", is that the same as this "electronics"?

Meanwhile, I checked for ground on MFS (black wire), and that seemed to be grounded (multi meter shows a short to steering column which I assume is grounded). I also checked for 12V at the 30A Fuse 10 in power distribution box, and it was getting voltage. I am in the process of removing wiper arms (pain in neck) to get to the motor itself so I can check 12 V there.

I do think there was water issue at the SJB and that's why blower and windows were having issues, but maybe that is not the issue since I dried the car out. Please let me know your thoughts.