I'm looking for someone with a good understanding of electrical circuits to help me examine the Thunderbird wiper circuit so that I can figure out how to control it with the SN95 stuff I have in my car (post SN dash swap). The SN95 stuff is very similar to the Fox Mustang stuff so I will be referencing the fox diagrams at times as well.
So, the first step is figuring out how the stock 88 Thunderbird circuits work. Here's the diagram I started with and what I think I know so far:
(http://img.photobucket.com/albums/v203/booksix/ThunderbirdWiper1.jpg)
I know a touch more but it's not necessary just yet. What I'm looking for first is an understanding of the three 'solid-line' wires going to the actual wiper motor (I'll get to the dashed line after). So, who can help?? :hick:
your whatever you posted,, is a red X.
here is a link to help from the diy link
http://www.foxtbirdcougarforums.com/showthread.php?t=11615
can you post up the SN95 wiper system?
it would be easier to cross breed the wiring.
i could overlap the two with the computer and tie in ckts ,,, im not familiar with the layout of the sn95 though.
do you still have the interval governer box?
That's strange, it shows fine here and is the same way I always post (photobucket). Try this: http://img.photobucket.com/albums/v203/booksix/ThunderbirdWiper1.jpg
Anyway, I thought about posting up the diagrams for cross reference but I was hoping to take it step by step so I might understand what I have and then try to figure out how to get there. But I can throw everything up...
I have the stock governer box, an SN95 box and could get a Fox 'stang box. I think some of the mustang guys have successfully wired the SN switch to the Fox 'stang governer so that may be a good place to start. The biggest issue with both Mustang boxes is that they have no circuits for parking the wipers but I can get to that after the wipers work...
Here's what I have:
http://img.photobucket.com/albums/v203/booksix/Untitled-1.jpg
http://img.photobucket.com/albums/v203/booksix/SNWiper2.jpg
http://img.photobucket.com/albums/v203/booksix/SNWiper1.jpg
http://img.photobucket.com/albums/v203/booksix/FoxStangWiper1.jpg
Ill be up in St Paul MN area and several surrounding states all week, taking off now to get the bird.
I'll try to make time in the hotel and fiddle with this if my site surveys go smooth as glass.
Sweet! You'll be kinda up there by my hometown (in WI). I'm kinda jealous, should be nice up there this time of year. Anyway, thanks for the help! Have a good trip!
The dashed line simply means there is a mechanical connection between the motor and the switch. Everything inside the box labeled "wiper motor/switch" is one unit. The switches would be part of the park circuit, which are activated if the wiper is not in the park position (it is this switch that makes the wipers park when you turn them off).
As for the function of those wires:
The dark blue wire is GROUNDED when the wiper switch is in the LOW or INTERMITTANT setting. This is the low speed feed.
The white wire is GROUNDED when the wiper switch is in the HI position. This is the high speed feed.
The yellow/red strip wire is the wiper motor's power feed. It will have 12 volts when the wiper switch is in any position except "OFF". It will also have power when the switch is off and the wipers are parking - once they're parked the power is cut off by the delay module.
When in INTERMITTANT mode the wiper motor is grounded through the dark blue wire just like it is in LOW, and the delay module gives a pulse of power on the yellow/red wire every time it wants to activate the wipers. Once this pulse has occured the wipers will return to the base of the windshield, but they will not park until the wiper switch is turned off.
Here's a better diagram that shows the inner workings of the wiper switch and the delay (governer) module
I'm just looking at the Mustang system (I looked at a 96) and you are definitely going to have problems with the park circuit. Fox Birdcats have two park circuits (hence the two switches in the diagram). One "park" circuit returns the wipers to the bottom of the windshield and is activated when the wipers are in pulse mode, the other pulls them down into the cowl when the wipers are off.
I did come up with a potential solution though: Use the delay module from a '92 Mark VII. The Mark VII uses a resistance-based switch sense like the SN95 Mustang but has provisions for the two park circuits of the T-Bird's wiper motor. I've just looked at the Mark VII diagram and it appears the resistance values in the switch are the same as the SN95 Mustang, so you should be able to use the Mustang switch, Mark delay module and T-Bird wiper motor... I say this as a theory, of course...
Nice, thanks for the input! I was wondering if there may be a unit that would combine proper resistances with a park circuit but had no idea where to look. Where did you source this info? Do you have any diagrams?
I've got diagrams. As for where I got the idea on the Mark VII module it was just a hunch. I knew the Mark VII would have a similar park mechanism to our cars and figured that since they were made into '92 they may have the more modern switch and module. I then compared a '95 Mustang diagram to the '92 Mark VII diagram to the '88 T-Bird diagram, and it looks to me like something could be made to work using components from all three systems (Mustang switch, Mark VII module, T-Bird wiper motor).
For the record, I've just checked and it looks like an '02 Mustang has the same switch resistance values as the '95, so you should be able to use the switch from any SN95 Mustang
For your perusal, here are the Mustang and Mark diagrams:
Thanks, I'll try to track down the Mark VII unit and update the thread :D
Hey Thunder Chicken, do you have diagrams for old Mark VII's as well? I know there are a few Mark VII's in the Junkyard here in San Diego but I doubt I'm lucky enough they are 92's. Just trying to figure out what years could all work... thanks!
edit: based on multifunction switches from rock auto it looks like they started that in '90. ??
Hmm...1990 was the first year for the airbag in the Mark VII, which required a square steering column cover, which probably also required the new wiper switch (same for Mustang, Taurus, etc.). That may be why 1990-92 switches are the same.
Just throwing that in there for ya. ;)
I'd say Eric's right about the air bag making the difference. I've just checked, and the '89 Mark VII wiper switch is the same wiring as the 88 T-Bird. '90 Mark VII is the same as the '92, so you should be good with 90-92.
Sweet, thanks guys, you're amazing! And once I get this done it's interfacing the 05 explorer steering wheel controls with the cruise control ;)
Come to think of it, maybe I should be thinking about this for my junkyard trip this weekend...
Thunder Chicken, any chance you have a diagram of showing the resistances of the 88 thunderbird cruise buttons (i got the 05 explorer diagram from autozone.com)? I have the page from the thunderbird evtm but it's a bit low in resolution to make out the numbers...
My Mitchell OnDemand diagrams don't show the resistance values in the switch. When I get a chance I'll check my EVTM (it's out in the garage, I'm not, so I can't look right now)
No sweat, thanks!
87 evtm
thanks!
So, I'm looking at the on/off circuit for the 'bird. What I get is; if I press on the signal return (LB/BK) gets full reference voltage and if I hit off the signal return is grounded. Is that correct?
Signal return is the term used in the EEC circuit to describe the logic ground for the 5v reference it uses for some of the sensors.
This doesn't apply here.
The input labeled "Horn" is the ground side of the horn relay coil.
When there is no current flowing through the relay coil (you are not blowing the horn) there is 12v on this input.
Pushing the cruise ON puts this 12v on the LB/BK wire.
Pushing the cruise OFF puts ground on the LB/BK wire.
Well, the 05 Explorer diagram uses the term "signal return" for the cruise as well as the EEC system; so that's why I used it. But wither way, thanks. Now my biggest problem will be getting a ground source on the steering wheel side of the clock spring (the 05 explorer system uses a resistor rather than a ground for off). Other than that it looks like a bit of rewiring within the switch itself should give me what I need! :D
Ok, so, I cross referenced the Mark VII governor on Rock Auto to figure out which cars at the junkyard had what I needed (thank you iPhone) and ended up getting one from a 92 Taurus LX.
First, I wired it up by purely color. The wipers worked and cycled but they seemed to stay in one speed regardless of the switch position. Next, I looked at the diagram and noticed red/yel and dk blu/org going to the motor where reversed (according to the position they entered the motor symbol on the diagram). I swapped those but that just reversed the problem and had the wipers trying to cycle downward toward the cowl.
I believe the wiring on the motor side of the governor was correct the first time but the signal wires from the wiper switch must be wrong and so color matching does not work. Does anyone have a more detailed diagram than the ones below to help me figure out how to wire the 3 signal wires from the 94-04 mustang wiper switch to the 90-95 Taurus governor? Here's what I'm working with:
Thunderbird:
(http://img.photobucket.com/albums/v203/booksix/ThunderbirdWiper1-1.jpg)
Taurus:
(http://img.photobucket.com/albums/v203/booksix/92TaurusWipers.gif)
Mitchell OnDemand's diagram is no better (it does not show the internal circuits in the governer), but it does provide some information in the troubleshooting section. According to it, you should have power on the yellow/red wire when the switch is in LO ir HI (the power will be pulsed in INT). You should have a ground on the dark blue/orange wire when the switch is in LO or INT. You should have ground on the white wire when the switch is in HI. This is the same as the T-Bird wiper motor.
Speaking of T-Bird wiper motors, here's the terminal layout of it.
Awesome, thanks. I'll check that out. As far as the wiring diagrams, do they show the internal circuits of the wiper switch by any chance? I think the problem lies between the switch and the governor so being able to test those circuits would be ideal.