TCCoA Forums banner

1 - 10 of 10 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
Does anyone have any input on correcting the following:

1990 Thunderbird SC - intermittent windshield wiper low condition won’t turn off when the dial is turned to the off position.


Thanks,


Rob
 

·
Super Moderator
Joined
·
10,375 Posts
That switch can't be cleaned; I'd say you need a new MFS.
 

·
Registered
Joined
·
1,811 Posts
When that happens on a Crown Vic, it's a short the wiper motor electronics from getting wet (bad design). The wipers just come on randomly, a few sweeps here and there like it's possessed.

Al
 

·
Super Moderator
Joined
·
10,375 Posts
The wiper motor itself is relay driven, so it would have to be a heck of a short.

But, the later cars show the MFS feeding the ICM, which is under the dash, above your left foot.
A short there could cause it.

I still bet it's the MFS. :)
 

·
Registered
Joined
·
7 Posts
Discussion Starter #5
The wiper motor itself is relay driven, so it would have to be a heck of a short.

But, the later cars show the MFS feeding the ICM, which is under the dash, above your left foot.
A short there could cause it.

I still bet it's the MFS. :)
Gentlemen,


What does the MFS refer to? I will check for shorts. I had concern that it may be tied to a faulty antique alarm system signal.

Thanks.


Rob
 

·
Super Moderator
Joined
·
10,375 Posts
 

·
Registered
Joined
·
1,811 Posts
Correct, the wiper motor issue is exclusive to the later model Crown Vic with electronics integrated into the wiper motor that will get wet if you don't keep the cowl area clean of leaves.

MFS stand for mother****ing switch, lol!
Actually, multi-function switch

Al
 

·
Super Moderator
Joined
·
4,898 Posts
The MN12s are a bit funky.

There's a park switch on the wiper motor that if it shorts, will keep it running.

Because it feeds the interval wiper controller (IWC further in this message), and tells the IWC when to shut the motor off (because it's parked).

But unlike other vehicles I've owned, it's not directly connected to ground to do the parking automatically.

So I'd check that, and then pick up a spare IWC from the boneyard and swap that.

The MFS is also a possibility, but you may want to check voltages around first.

RwP
 

·
Registered
Joined
·
7 Posts
Discussion Starter #9
Grog6,


Thank you. I started to take a look.



Rob
 

·
Registered
Joined
·
7 Posts
Discussion Starter #10
The MN12s are a bit funky.

There's a park switch on the wiper motor that if it shorts, will keep it running.

Because it feeds the interval wiper controller (IWC further in this message), and tells the IWC when to shut the motor off (because it's parked).

But unlike other vehicles I've owned, it's not directly connected to ground to do the parking automatically.

So I'd check that, and then pick up a spare IWC from the boneyard and swap that.

The MFS is also a possibility, but you may want to check voltages around first.

RwP

RwP,

Thanks. I will do some studying of the manual. I haven’t had much of a chance so far. I do have a spare SC that was awaiting head gasket replacement. I will swap from there.

Thanks,


Rob
 
1 - 10 of 10 Posts
Top