Bronco Forum - Full Size Ford Bronco Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
71 Posts
Discussion Starter #1
This is the black box between the wiper switch on the dash and the harness. I believe mine to be bad (when wipers are on, they freeze up, then start again, etc. randomly), so I was wondering how you could bypass the black box. I don't use the intermittent wiper feature anyway, just high/low. Does anyone have a wiring diagram?

My motor is good because when run power right to the motor, it operates fine.
 

·
Super Moderator
Joined
·
25,833 Posts

·
Super Moderator
Joined
·
25,833 Posts
I forgot to include this due to COMCAST's 1993 Cable Connection Speed!

multi function switch (MFS) on column,,,
Testing by Steve83
http://www.supermotors.net/registry/media/225114_1
"...the MFS testing is done disconnected; it's strictly an internal test of the MFS...
Check contacts. clean em up
Multifunction Switch (MFS) Cleaning & Internal pics in a 2001 Explorer; Miesk5 NOTE, as Steve wrote it should be electrically & functionally identical to our years; "...Wipe with a rag, hit with contact cleaner and an old toothbrush to clean. Regrease with dielectric grease. Save ~$80 for a new switch that will only last ~4 years..."
Source: by Electrohacker at sites.google.com
 

·
Super Moderator
Joined
·
25,833 Posts

·
Registered
Joined
·
71 Posts
Discussion Starter #6

·
Registered
Joined
·
71 Posts
Discussion Starter #7
Well, I tried that and the wipers aren't moving at all now. I can hear some not so nice noises coming from the switch and the wiper motor, but no action. Does this point to a bad MFS??
 

·
Super Moderator
Joined
·
25,833 Posts
yo, ok.. I can't think right now; I am away and really can't jump between open browsers.. to read diagrams.
read thru all of this post;
Switch Repair in an 87 (pics are gone)
Source: by RickyB at http://www.fullsizebronco.com/forum/showthread.php?t=136770

including what Steve83 & RescueBronco wrote..
 

·
Registered
Joined
·
71 Posts
Discussion Starter #9
yo, ok.. I can't think right now; I am away and really can't jump between open browsers.. to read diagrams.
read thru all of this post;
Switch Repair in an 87 (pics are gone)
Source: by RickyB at http://www.fullsizebronco.com/forum/showthread.php?t=136770

including what Steve83 & RescueBronco wrote..
Yep, I saw that one, thanks. I took apart my governor but everything looks fine on the board - no loose soldered connections.

Basically what happens is I will turn on the wipers and it will wipe for 1-2 strokes, then freeze. I will hear a clicking from the governor and/or MFS, then the wipers might move a bit, then freeze, etc.

So I don't know if it's the MFS or the governor or both. That's why I tried to bypass the governor, but even that is not working. Maybe it's the damn MFS then? I dunno.
 

·
Registered
Joined
·
71 Posts
Discussion Starter #10
Alrighty, I completely removed the motor and ran the motor load test. Motor should not pull more than 3.5A at any time (disconnected).

1. High speed = ~8.1A
2. Low speed = ~3.5A

I guess the motor is going bad? Motor was pulling more amps when connected up...8+ low, 13+ high
 

·
Super Moderator
Joined
·
25,833 Posts
yo,
Sorry.. had to run out a few times over past few days...

Yep..that doesn't llok good in High..bet those wries got Hot!
Check this out by Blackwater Pirate & Steve83'

Blackwater Pirate:
I have a 1990 E.B. w/5.0L/Auto. I've been going through my new-to-me/used Bronco. I found out the wipers are acting screwy. When I turn them on there's a strange noise coming from under the cover near the switch. It has Intermittent wipes. It's coming from the black box under there. Is this that Wiper Control module that I've read in a couple of post that others have had problems with? Or could it be something else? It only makes noise when I turn the wipers to any on position i.e. Intermit/Low/High. Any thoughts?

Steve; the WCM is only used on '92-up. Your truck has an interval governor, and they don't usually go bad internally. Diagnose the wiring between the governor & motor, and diagnose the motor (the most likely cause of any wiper problem). The Haynes manual wiring diagrams show everything, so pick one up if you don't have it already. PN 36058 w/light blue cover.

Blackwater Pirate; Fixed! The wiper contact disc thingy in the motor had some ugly grease in there. I cleaned it with a rag and electrical cleaning spray. I applied some fresh dielectric grease and tried it. It worked flawless in all positions! Yeehaa! At the same time I had to track down some other weird crap that seemed to happen all at the same time I was fixing this. Mostly loose connections and dirty contacts!
 

·
Registered
Joined
·
71 Posts
Discussion Starter #12
OK, figuring this is a motor problem, I just bought a reman motor.

Load test NEW motor (disconnected from linkage)
1. High speed = 2.0 A
2. Low speed = 1.1 A

After some more reading it would appear there is a circuit breaker in the MFS. If the load becomes too high (as in my case), the circuit breaker trips. The circuit breaker is rated for 7A. If I'm pulling 13+, that's gotta come into play. Well looks like the circuit breaker was working. :)

As far as your last post, I think it's strange that cleaning of those contacts inside the cover fixed that guys problem. AFAIK, those contacts are for wiper arm parking. Well, at least on mine motor there are 2 plugs - one for the parking mechanism and one for power to the motor. There is no way to get to what's inside the motor unless I disassemble it - which I did - but there are no obvious corroded connections, etc.

One tip, before installing the new motor, check under the plastic cover. My new motor had NO dielectric grease on the parking mechanism. Hecho en Mexico. Threw some grease on there to avoid future problems.

Reassembling now...
 
1 - 13 of 13 Posts
Top