1989 Ford L8000 Wiper Motor Circuit... This complicated??

[BenPPG]

Hi All - struggling with making an 89 Ford wiper motor function correctly without the original factory switch. The factory switch had 7 terminals and no relay, here is the factory wiring schematic:

I have a universal 4 pin wiper switch and I can't figure out how to get this to work with a combination of this universal switches and relay(s). I've got a number of 4 and 5 pin relays availiable.

Essentially how I understand this is the Green wire needs to the power yellow wire (when running low or high), for Low, the blue wire needs to be grounded, and for High, the white orange wire needs to be grounded. Then for Park, the red wire needs to power the yellow wire and blue needs to be grounded via Black-White instead of the standard black ground wire.

I can get it to function making those connections manually but I can't figure out how to make it work using the universal switch. No idea they were this complicated.. can anyone please help?!

Thank you!!!

 

[Diver300]

This should work.

I am assuming that the switch that you have has terminals for common, Off, Low and High speed.

The park switch is shown in the parked position, so wire 28 needs to be earthed. Wire 63 is to be connected to the normally open connection of the relay. Wire 65 is to be connected to the "Off" terminal of the control switch.

The circuit has the disadvantage that the relay will be energised the whole time that the ignition is on and the wipers aren't on. The wipers won't self-park if they are running when the ignition is on. The supply to the circuit has to be from the ignition supply. If not the relay will be taking current all the time, which will run the battery down.

 

[crutschow]

This should work.

I see at least one difference
The wiring diagram shows the battery connected to yellow wire for both the HI and LO settings.
You show that voltage moving between terminals.
So you would have make the yellow wire common and the battery connection change between White-Orange and Blue wires.
That would likely cause the motor to turn backwards, and I don't know it that's a problem.

 

[Diver300]

I see at least one difference
The wiring diagram shows the battery connected to yellow wire for both the HI and LO settings.
You show that voltage moving between terminals.
So you would have make the yellow wire common and the battery connection change between White-Orange and Blue wires.
That would likely cause the motor to turn backwards, and I don't know it that's a problem.

Yes, the motor would turn backwards. However, you could just swap the ignition supply and the three earth wires.

 

[BenPPG]

I appreciate the responses thank you, I am still confused on how to make this work. I am having trouble interpreting the diagram.. the Green wire is a fused ignition wire, only gets power in on position. The park switch is integrated into the motor..I only have green/red/Black-White going to that plug.. would this solution use a 5 pin relay?

 

[crutschow]

Here's Driver300's connection diagram with the ignition and grounds reversed to get the proper motor polarity.
I also added the wire colors to help in understanding the connections.

 

[crutschow]

I only have green/red/Black-White going to that plug.

So the external wiring is not as shown in the diagram you posted with 6 connections between the switch and wiper motor?

 

[BenPPG]

Well the motor itself under the hood has two 3-pin plugs

#1 (White/Orange, Blue, Yellow)
#2 (Green, Red, Black/White)

I have found those 6 wires in the dash, plus an additional black ground wire. It's a nightmare in there, everything was cut/melted when I got it so I have no idea what went where.

My only other question is for the bottom side of the relay.. I have Bosch style 4&5 pins.. would I use a 4 pin here? I am unsure what the square symbol means.

Really appreciate everyones help on this!!! Amazing.

 

[crutschow]

I have Bosch style 4&5 pins.. would I use a 4 pin here?

Likely the 5-pin since that's how many a SPDT relay has, which is used here.
Model numbers?

 

[BenPPG]

These are the 5 pin relays I have:

 

[Diver300]

On those relays, pin 30 is the one I labelled "COM", meaning "common". Pin 87 is "NO" or "normally open". Pin 87a is "NC" or "normally closed".

Pins 85 and 86 are the relay coil. I haven't labelled those on my diagram, but they are the remaining two connections on the relay. It doesn't matter which way round those two go.

The diagram that I drew is similar to what is on the side of the relays.

 

[BenPPG]

On those relays, pin 30 is the one I labelled "COM", meaning "common". Pin 87 is "NO" or "normally open". Pin 87a is "NC" or "normally closed".

Pins 85 and 86 are the relay coil. I haven't labelled those on my diagram, but they are the remaining two connections on the relay. It doesn't matter which way round those two go.

The diagram that I drew is similar to what is on the side of the relays.

So essentially, the green ignition supply will have a jumper between pins 85 and 86, blue on 30 and 87a (no jumper), and red on 87?

 

[crutschow]

So essentially, the green ignition supply will have a jumper between pins 85 and 86, blue on 30 and 87a (no jumper), and red on 87?

There is no jumper as that would short the coil.
If there is no dot, then the wires are just crossing with no connection.

The ignition goes to one pin (say 85) and pin 86 goes to the Green Off/Park terminal on the switch.
Pin 30 goes to the blue.
Pin 87A goes to the Low pin on the switch.
Pin 87 goes to the Red.

Incidentally, if you are interested in adding an intermittent wiper option, that can be done with an added DPDT switch, an SCR, and a 555 timer one-shot.

 

[BenPPG]

OK thank you for the clarification. I think the intermittent option is above my pay-grade

Then in that case - does the Dot here mean Yellow and Green should be connected together on that side of the coil?

 

[crutschow]

does the Dot here mean Yellow and Green should be connected together on that side of the coil?

The dot only connects wires that go to the dot.
Wires that cross without a dot have no connection.
Connecting Yellow and Green would obviously short across the relay coil.

The dot connects the Ignition, Yellow, Bk-White, and one side of the coil.
The is no dot, so there is no connection between the Green and the above.
The Green from Park Switch goes to the selection switch, and the other side of the coil.

 

[BenPPG]

Having trouble getting this working.. I tried to make a diagram that represents the wires I am dealing with in the dash.

I have the 7 wires here all just cut in the dash.. I tried to represent how I made the connections and with this setup nothing works. The wiper switch, relay, and connection are all right next to each other in the dash.

The wiper Motor has 6 connections and 2 pigtails (3 wires each, connected to motor assembly via factory plugs).

For now I've just gotten Low and High to function and bypassed the Park feature altogether.

 

[crutschow]

For now I've just gotten Low and High to function and bypassed the Park feature altogether.

One error I see is that you have the top connection on the wiper Park Switch going to the ign supply.
As you can see from my diagram, it's supposed to go to the switch off/park position terminal.
Making the two wires both green, may have led to your confusion.

 

[BenPPG]

Green (Ignition supply) is hot when I turn key on.. If I connect to the Park position terminal (on the wiper switch) it blows fuse which makes sense because its then connected directly to ground.

 

[crutschow]

If I connect to the Park position terminal (on the wiper switch) it blows fuse which makes sense because its then connected directly to ground.

Not in my circuit.
Do you have trouble following the wiring diagram I posted?
Did you not understand my explanation about where you circuit is incorrect?

 

[BenPPG]

Yes I am having trouble, the diagram I sent is how I interpreted your diagram. I have zero experience with reading wiring diagrams..

I am simply looking at a rats nest of 7 cut wires in the dash and trying to make the right connections so they don't melt like the last guy did.