Wiper Motor Wiring Question (1 Viewer)

[40Man]

Picked up a NOS motor (85120-90802) to replace my 85120-90810.

I have tested the wires and have determined which wires are +1 +2 Constant power and switch.

When I hook up to the new motor and turn on acc power (wiper off) I get a 12v reading out of every wire instead of just the constant power wire. When the old tired wiper is hooked up it still works (just tired) and only get 12v running on the power wire in acc w wiper off (as it should).

Tried switching wiring around to no avail. 12v to all 4 no matter what, and new wiper motor does nothing. Very strange.

 

[samatulich]

You may be looking for a ground when the switch is pulled out. What year is the vehicle and what size motor did you replace it with. There is a large motor (78+) and small motor (75-77) it think. They are wired differently.

 

[40Man]

You may be looking for a ground when the switch is pulled out. What year is the vehicle and what size motor did you replace it with. There is a large motor (78+) and small motor (75-77) it think. They are wired differently.

I have an 82 large motor. The replacement PN also says 78-84 and is the same size.

 

[Bear]

Trying to compare your wiring set-ups on the two motors and cannot clearly see where each wire either connects to the motor terminal or heads into the motor casing. I have several different motors and will try to help you but need to know where the wires are connected.
Where does the LW wire connect on your original 810 motor?

 

[40Man]

The LW on the original was bottom right. Here is the original car wiring plug. Seems strange that power would flow to all four wires (wiper off acc power on) once hooked to the new motor. Normally I can figure these things out but this is beyond me.

Trying to compare your wiring set-ups on the two motors and cannot clearly see where each wire either connects to the motor terminal or heads into the motor casing. I have several different motors and will try to help you but need to know where the wires are connected.
Where does the LW wire connect on your original 810 motor?

My old motor was wired like this

Trying to compare your wiring set-ups on the two motors and cannot clearly see where each wire either connects to the motor terminal or heads into the motor casing. I have several different motors and will try to help you but need to know where the wires are connected.
Where does the LW wire connect on your original 810 motor?

 

[Bear]

This gets confusing in several ways. Toyota's wiring diagrams are usually for one specific year, but changes were made to components and to wire colors over the years. Actual on-the-car wire colors can not only be different from the paper diagram, but also can change at snap-on connectors. The actual electrical path thru the dash switch and thru the motor's reed switch can vary: most motors were ground-switched, but 90808 is hot-switched, and usually uses the standard dash switch but wires it differently. The intermittent function uses a different switch and wiring.

My research shows that the 90810 you had was for 10/81-10/85 cold-weather use. You may have a European-delivered model. The 90802 you are substituting came from a progression of motors starting with 90303 in 1/75 up through 90308 to 90802 ending in 10/81. I'm assuming your truck is 1982 vintage.

The ground switched motor from 10/81-10/85 should be 90810.
The hot switched motor from 10/81-10/85 should be 90808.

I believe the wiring for 90802 is:
LW and LR go directly into the motor case.
L goes to the first motor terminal and then on into the motor case.
LB goes to the center motor terminal.
B is from a grounded location to a screw on the motor and then on to the 3rd motor terminal.

LW = low speed
LR = high speed
LB = park carrier
L = hot to common brush full-time
B = ground

Is this what you have?

I cannot see all the colors and locations on your 90810. Can you specify?

If you are testing all this on-the-car, be aware that the ground wire which on some models was wired to the exterior motor cover, may not fully ground due to the rubber cover gasket. Best to use a toothed washer and ground to the windshield frame.

 

[samatulich]

You may try and remove the wiper switch from the dash and test the new wiper motor on the bench. You’ll have to make a wire harness, but you can play around with the setup much easier than on the vehicle. I did this over the winter when I installed an aftermarket wiper motor, sure made my life easier. These motors are very simple, you’re just trying to complete the circuit.

 

[40Man]

This gets confusing in several ways. Toyota's wiring diagrams are usually for one specific year, but changes were made to components and to wire colors over the years. Actual on-the-car wire colors can not only be different from the paper diagram, but also can change at snap-on connectors. The actual electrical path thru the dash switch and thru the motor's reed switch can vary: most motors were ground-switched, but 90808 is hot-switched, and usually uses the standard dash switch but wires it differently. The intermittent function uses a different switch and wiring.

My research shows that the 90810 you had was for 10/81-10/85 cold-weather use. You may have a European-delivered model. The 90802 you are substituting came from a progression of motors starting with 90303 in 1/75 up through 90308 to 90802 ending in 10/81. I'm assuming your truck is 1982 vintage.

The ground switched motor from 10/81-10/85 should be 90810.
The hot switched motor from 10/81-10/85 should be 90808.

I believe the wiring for 90802 is:
LW and LR go directly into the motor case.
L goes to the first motor terminal and then on into the motor case.
LB goes to the center motor terminal.
B is from a grounded location to a screw on the motor and then on to the 3rd motor terminal.

LW = low speed
LR = high speed
LB = park carrier
L = hot to common brush full-time
B = ground

Is this what you have?

I cannot see all the colors and locations on your 90810. Can you specify?

If you are testing all this on-the-car, be aware that the ground wire which on some models was wired to the exterior motor cover, may not fully ground due to the rubber cover gasket. Best to use a toothed washer and ground to the windshield frame.

Yes, this is how I am wired w my old motor.

Top left lr
Top right lb
Bottom left L
Bottom right lw

New motor

Top left lr
Top right lw
Bottom left lb
Bottom right L


Tried matching colors to new motor and still no go and all wires 12v w acc on and wipers off

The LW just came un soldered but was on the middle prong on the old motor.

 

[Bear]

Thanks--the 90802 photos clearly show the connections--and they are correct. This motor appears to be the same as the 90804, at least as it is externally wired.

Does it appear that on your 90810 motor that someone has re-soldered some of the wires onto the gearcase terminal pad?
Also the LW soldered onto the center terminal doesn't seem correct, unless someone has played with the wire colors leading up to the LW. Do all the wires in the windshield wiper loom seem to be in their original spots within the plastic connector?

I believe that your new 90802 motor is ground-switched, but I am not sure about your 90810 motor. Is it possible that you have replaced a hot-switched motor with a ground-switched motor, or that someone in the past has previously switched-around various wires on the motor and/or the loom? Is there continuity of color for the original windshield wire loom-to-the original motor loom? If so, you say you have determined which of the wires is hot, ground, low speed, high speed, and park-- can you describe which is which?

 

[40Man]

Thanks--the 90802 photos clearly show the connections--and they are correct. This motor appears to be the same as the 90804, at least as it is externally wired.

Does it appear that on your 90810 motor that someone has re-soldered some of the wires onto the gearcase terminal pad?
Also the LW soldered onto the center terminal doesn't seem correct, unless someone has played with the wire colors leading up to the LW. Do all the wires in the windshield wiper loom seem to be in their original spots within the plastic connector?

I believe that your new 90802 motor is ground-switched, but I am not sure about your 90810 motor. Is it possible that you have replaced a hot-switched motor with a ground-switched motor, or that someone in the past has previously switched-around various wires on the motor and/or the loom? Is there continuity of color for the original windshield wire loom-to-the original motor loom? If so, you say you have determined which of the wires is hot, ground, low speed, high speed, and park-- can you describe which is which?

The wires all line up with continuity of color from the switch. I cut and added disconnects before the plastic connector to try and figure the right combo. The solders don't appear to be redone.

I confirmed that the following was the setup for my old motor and loom to plastic connector:

LW = low speed
LR = high speed
LB = park carrier
L = hot to common brush full-time
B = ground

No idea what the new motor wants


Where I am confused is how I am getting 12v on all circuits in acc w motor off when the new motor is hooked up no matter how I configure the wires (tried many combos). Somehow the motor is linking all the wires together since only L should be hot in ACC position w motor off...

Thanks for your assistance.

 

[40Man]

Pix of the switch

 

[Bear]

With your new motor off the car and on the bench, the L wire connected from Battery (+) to the first terminal on the gearbox (L), and the B wire connected to the Battery (-) , connecting another ground wire to either the LW or the LR wires of the motor should cause the motor to spin.

You have tried this and no go?
You replaced the original motor because it was "slow," but it did work in low, high, and park?
Looking at the screw heads, you are certain that the new motor has not been opened and no outward signs of having been dropped?
Solder joints are tight, all terminals in the connector are okay?

I don't understand the broken wire on the 90810 motor--LW--being connected to the center terminal on the gearbox terminal pad, unless the motor is hot-switched. On a ground-switched motor, the LW wire goes directly into the motor casing to run the low speed; the center terminal is to accept the Park wire--LB.--

My confusion is with the wiring to and within your 90810 motor. It appears the 90810 motor and the 90802 motor are not the "same." Some of what I see on the 90810 motor indicates it is hot-switched. The 90802 motor appears to be the standard ground-switched and likely will run correctly with the correct wiring to it. Your 90810 motor does not use the same color wires as the 90808 hot-switched motors I have seen, but my conclusion is that it is in fact hot-switched, regardless of the wire colors. Unlike the 90808 hot-switched motor, your 90810 motor appears to have a direct ground connection at the gearbox terminal pad--this may be the difference between "cold-spec" or "Arctic" and standard usage.

If your truck was wired for hot-switching its original wiper motor, you should see 12V(+) at either the LR or LB wires exiting the windshield wiper harness when the dash wiper switch is pulled to either slow or fast speeds. If so, trying to use a ground-switched motor in a wiring set up for hot-switching won't work, and you will have to rearrange how the ground and hot signals arrive at the new motor to make it work properly.

I have info on the 90808 hot-switched motor if you need it.

Sure hope this helps you.

 

[Bear]

The wires look correct on your wiper switch: LY, WB, LR on top row; LW, B, LB on bottom row. This is switch 84652-27010 and was in standard use from 9/77-10/85. It is used in either ground-switched circuits or hot-switched.

Since it is out of the car, you can hook it up to a battery with some spare wires and create the entire wiper circuit. But be aware that Toyota doesn't seem to show a hot-switched wiper circuit for the 40-series, and there has been some discussion of errors in the wiring diagrams: there are diagrams incorrectly showing hot-switched circuits with 12V (+) connected to the common brush and vice-versa.

Again, I'm guessing your vehicle was a non-USA import--likely European or possibly Middle Eastern--and may have used a hot-switched wiring circuit to power the wipers.

 

[40Man]

The wires look correct on your wiper switch: LY, WB, LR on top row; LW, B, LB on bottom row. This is switch 84652-27010 and was in standard use from 9/77-10/85. It is used in either ground-switched circuits or hot-switched.

Since it is out of the car, you can hook it up to a battery with some spare wires and create the entire wiper circuit. But be aware that Toyota doesn't seem to show a hot-switched wiper circuit for the 40-series, and there has been some discussion of errors in the wiring diagrams: there are diagrams incorrectly showing hot-switched circuits with 12V (+) connected to the common brush and vice-versa.

Again, I'm guessing your vehicle was a non-USA import--likely European or possibly Middle Eastern--and may have used a hot-switched wiring circuit to power the wipers.

Thanks. I will bench test tomorrow. My 40 is definitely a U.S. model. Started its life in Alaska and the second owner had it since the mid-eighties in Seattle. I'll post results when I figure it out.

 

[CHCP]

Thanks. I will bench test tomorrow. My 40 is definitely a U.S. model. Started its life in Alaska and the second owner had it since the mid-eighties in Seattle. I'll post results when I figure it out.

Can you show the female to your dash wire harness? I had a problem hooking up a 78 wiper motor with a 77 dash wire harness. the dash wire connector did not have a ground connecting to the bottom middle black wire of the switch connector. also the wiring diagrams for the 77 and 78 motors were different and if I remember correctly using the 77 wire harness and 78 motor the resulting hookup was different than the 77 or 78 wire diagrams.

 

[40Man]

Can you show the female to your dash wire harness? I had a problem hooking up a 78 wiper motor with a 77 dash wire harness. the dash wire connector did not have a ground connecting to the bottom middle black wire of the switch connector. also the wiring diagrams for the 77 and 78 motors were different and if I remember correctly using the 77 wire harness and 78 motor the resulting hookup was different than the 77 or 78 wire diagrams.

Yeah, I will send a send a pic when I can. I hooked my old motor up until I can figure it out.