Chassis Wiring help - wipers

[TurboSE]

Hey guys and gals...I've started planning my chassis wiring for my 1992 S13 coupe. I will be wiring most of the circuits to toggle switches. So far, the only circuit I've found that I cannot (easily) wire on a toggle is the wipers/washer...which is ok, I can deal with multiple speeds. I have decided to go with a one-off (read: simplified) version of the factory wiring lay-out...what concerns me is the Time Control Unit. Below is the wiring diagram I made (copied from the FSM), since the only circuit controlled by the TCU I will be using is wipers/washer...will this set-up be sufficient to make them both work, or do I need to wire anything else into the TCU?

Any help or info is appreciated...Thanks in advance!

http://memimage.cardomain.com/member_images/11/web/2243000-2243999/2243246_38_full.jpg?095122-311

[GSXRJJordan]

It looks complete, but there's really no way to tell except to hook it up and find out. Are you trying to mimic OEM functionality (or do you just want off/full speed)? Do you still have the wiper stalk?

[TurboSE]

I still have the stalk...I'd be happy with off/high, but it looks like it might just be easier to mimic the OEM set-up...

[TurboSE]

another, semi-off-topic question...what size maxi-fuse should I use? Is 100A too big?

[SoguRacing]

take a look at what fuses are running the wiper motor and the washer motor then combine them. that should give you what you need since they will rarely be running simultaneously. Man, i can read schematics but this one is confusing. I have the wiring diagram somewhere from mitchell. i'll see if i can photo it on here.

[TurboSE]

sorry...I was vague with my last question...I meant the maxi-fuse that comes right after the battery for the whole chassis...

[SoguRacing]

...the fusible 75amp link is what you're referring to. "gray in color"

[SoguRacing]

you should just make a harness using different ohmed resistors. shouldn't cost that much.

[GSXRJJordan]

you should just make a harness using different ohmed resistors. shouldn't cost that much.

If he's got the stalk, he doesn't need to do that. When you twist the knob, it's a potentiometer that changes the voltage. Problem is, the stalk shouldn't have all the power for the wiper motor running through it, so you have the window amp to help out.

If you have the stalk and the amp wired up as you show above, you should be good.

[TurboSE]

...the fusible 75amp link is what you're referring to. "gray in color"

Thanks, I plan on running 1/0 gauge battery wire with a "branch" (8 gauge?) to my hot fuse panel, and 4 gauge to the starter. I seem to be having trouble locating a maxi-fuse holder in 1/0 gauge. Does anyone see a problem with running an ANL type fuse instead of a maxi? Would there be a better alternative than maxi or ANL?

[TurboSE]

If he's got the stalk, he doesn't need to do that. When you twist the knob, it's a potentiometer that changes the voltage. Problem is, the stalk shouldn't have all the power for the wiper motor running through it, so you have the window amp to help out.

If you have the stalk and the amp wired up as you show above, you should be good.

I'll probably be giving it a go next weekend, I'll be sure to update on my progress...

[g6civcx]

Alright, good job on recreating your own wiring diagram. Listen up very carefully as no one in this thread has given you enough info to do what you want to do.

Let's look at every component:

wiper motor:
light green - 20A fused current, shared with the wiper amp and washer motor
orange - used by the wiper amp, this wire shows ground when the wiper arms are away from the base position and nothing when the wiper arms are at the base position, more on this later
black - ground
light green/black - goes to the high position on the switch
light green/red - goes to the low position on the switch

The washer motor works like this. It gets power via the light green wire and ground via the black wire. When you want the motor to move at high speed, you ground the light green/black wire. Current will flow from the light green wire, through the hi speed motor, to the light gree/black wire, and to ground.

Similarly, if you want low speed, you ground the light green/red wire. Current flows from the light green wire through the low speed motor, to the light gree/red wire, and to ground.

The auto return function can be used by monitoring ground on the orange wire. If the arms are away from base, this wire shows ground. If the arms are at base, this wire shows nothing. More on this in the wiper amp section.

So if you just want to reuse the wiper motor and nothing else, you just need to hook up current to the light green wire, and a 20A switch to the light green/black or light green/red wire, depending if you want high or low speed, then ground the switch. Any time you hit the switch, the wipers will move.

You can also utilize the auto retract function by using the orange wire if you want. What you need to do is ground either the green/black or green/red wire (I recommend light green/red for low speed retract) any time the orange wire shows ground. You can do this with a standard relay. Run constant or switched power to a fuse and to either pin 85/86. Run the other of 85/86 to the orange wire. Run light green/red or light green/black to one of pins 37/87 and the other of 37/87 to ground.

So any time the orange wire shows ground, current will run through pins 85/86, and pins 37/87 will be connected, and the wire to the motor will be grounded = auto retract until return to base. Then the orange wire will show nothing and turn off the relay.

The wiper amp can be used for the auto retract function. it also does int wipers, more below:
black - ground
orange - goes to wiper motor, see ground when arms are up and nothing when arms are down
light green/black - goes to TCU
light green - 20A current shared with wiper motor and washer
brown - goes to the low speed wire of the motor via the switch. this wire is only connected when the switch is OFF or INT. it lets the wiper amp know not to intervene until the switch is OFF or INT. So if the switch is LO or HI the wiper amp doesn't intervene.

When the wiper amp detects that the wiper switch is in the OFF or INT position via the brown wire, it's time for the wiper amp to intervene. The amp provides auto return function.

For auto return, the amp checks the orange wire, and if the switch is OFF or INT, and there is ground on the orange wire, the amp will ground the light green/black wire, which is connected to the TCU, the switch, and ultimately the low speed wiper motor. With this set up, when you turn the switch to off or int, and the arms are away from base, the wiper amp will return the arms to base with low speed.

If you want to reuse the wiper amp for auto return, you can connect black to ground, orange to wiper motor, light green/black you can leave out if you don't want variable wipers, light green to swithed or constant current, and brown you can tap into the low speed or high speed wiper motor.

TCU controls variable wipers as well as other timed function on the car. you don't need this if you don't want variable wipers. I won't discuss in too much detail. Consult FSM if you want to use it.

The TCU gets a ground signal from the wiper switch via the blue/yellow switch to let the TCU knows that the switch is in INT mode. Then the TCU uses the purple wire to see how fast you want the variable speed to be.

Then the TCU sends a signal to the wiper amp via the light green/black wire to tell the wiper amp to move the wiper arms. Once the wiper arms have moved, the TCU goes to sleep and lets the wiper amp return the arms to base. Then after a specific time based on how much you set the variable speed, the TCU wakes up and sends another signal to the amp to move the arms. Then goes back to sleep. Repeat.

The wiper switch itself is very simple. Follow the FSM wiring. Generally it gets power, wiper motor connections, washer connection, wiper amp connections, and TCU connections. Stare at the FSM for a while and you will see how the wires line up and how the wires are connected depending on where the switch is at.

The washer is very simple. Power goes to the washer and then to the switch. When you pull the switch, it grounds the washer = squirt and it also triggers the TCU to swing the wipers 2 times for every squirt.


I know that's a lot but it can be simple if you just want a high speed switch with no auto return. It's annoying and doable if you don't mind moving the arms to where you want and then shutting it down with no auto retract help.

The washer is also very simple. You can just connect the washer ground wire to a switch and then ground.


Any questions? Don't ever say Zilvia is ignorant or don't want to help you out.

[g6civcx]

another, semi-off-topic question...what size maxi-fuse should I use? Is 100A too big?

Fuse size is a function of the size of the wire. The size of the wire is a function of the total load you expect to pull on the circuit and the design of the circuit itself.

This is a whole different topic. There's no simple answer. It depends on your wiring diagram and how you run the wires.

Did you know that electrical engineers have problems with this issue?

[tre4s13]

Hope this help, well it better...cause I JUST photoshopped it for you...

http://s358.photobucket.com/albums/oo26/tre4s13/JustForYou/?action=view&current=TCU.jpg

[surreybc]

ImageShack - Hosting :: img0007ql9.jpg (http://img169.imageshack.us/my.php?image=img0007ql9.jpg)
ImageShack - Hosting :: img0029bj0.jpg (http://img169.imageshack.us/my.php?image=img0029bj0.jpg)

[TurboSE]

Alright, good job on recreating your own wiring diagram. Listen up very carefully as no one in this thread has given you enough info to do what you want to do.

Let's look at every component:

wiper motor:
light green - 20A fused current, shared with the wiper amp and washer motor
orange - used by the wiper amp, this wire shows ground when the wiper arms are away from the base position and nothing when the wiper arms are at the base position, more on this later
black - ground
light green/black - goes to the high position on the switch
light green/red - goes to the low position on the switch

The washer motor works like this. It gets power via the light green wire and ground via the black wire. When you want the motor to move at high speed, you ground the light green/black wire. Current will flow from the light green wire, through the hi speed motor, to the light gree/black wire, and to ground.

Similarly, if you want low speed, you ground the light green/red wire. Current flows from the light green wire through the low speed motor, to the light gree/red wire, and to ground.

The auto return function can be used by monitoring ground on the orange wire. If the arms are away from base, this wire shows ground. If the arms are at base, this wire shows nothing. More on this in the wiper amp section.

So if you just want to reuse the wiper motor and nothing else, you just need to hook up current to the light green wire, and a 20A switch to the light green/black or light green/red wire, depending if you want high or low speed, then ground the switch. Any time you hit the switch, the wipers will move.

You can also utilize the auto retract function by using the orange wire if you want. What you need to do is ground either the green/black or green/red wire (I recommend light green/red for low speed retract) any time the orange wire shows ground. You can do this with a standard relay. Run constant or switched power to a fuse and to either pin 85/86. Run the other of 85/86 to the orange wire. Run light green/red or light green/black to one of pins 37/87 and the other of 37/87 to ground.

So any time the orange wire shows ground, current will run through pins 85/86, and pins 37/87 will be connected, and the wire to the motor will be grounded = auto retract until return to base. Then the orange wire will show nothing and turn off the relay.

The wiper amp can be used for the auto retract function. it also does int wipers, more below:
black - ground
orange - goes to wiper motor, see ground when arms are up and nothing when arms are down
light green/black - goes to TCU
light green - 20A current shared with wiper motor and washer
brown - goes to the low speed wire of the motor via the switch. this wire is only connected when the switch is OFF or INT. it lets the wiper amp know not to intervene until the switch is OFF or INT. So if the switch is LO or HI the wiper amp doesn't intervene.

When the wiper amp detects that the wiper switch is in the OFF or INT position via the brown wire, it's time for the wiper amp to intervene. The amp provides auto return function.

For auto return, the amp checks the orange wire, and if the switch is OFF or INT, and there is ground on the orange wire, the amp will ground the light green/black wire, which is connected to the TCU, the switch, and ultimately the low speed wiper motor. With this set up, when you turn the switch to off or int, and the arms are away from base, the wiper amp will return the arms to base with low speed.

If you want to reuse the wiper amp for auto return, you can connect black to ground, orange to wiper motor, light green/black you can leave out if you don't want variable wipers, light green to swithed or constant current, and brown you can tap into the low speed or high speed wiper motor.

TCU controls variable wipers as well as other timed function on the car. you don't need this if you don't want variable wipers. I won't discuss in too much detail. Consult FSM if you want to use it.

The TCU gets a ground signal from the wiper switch via the blue/yellow switch to let the TCU knows that the switch is in INT mode. Then the TCU uses the purple wire to see how fast you want the variable speed to be.

Then the TCU sends a signal to the wiper amp via the light green/black wire to tell the wiper amp to move the wiper arms. Once the wiper arms have moved, the TCU goes to sleep and lets the wiper amp return the arms to base. Then after a specific time based on how much you set the variable speed, the TCU wakes up and sends another signal to the amp to move the arms. Then goes back to sleep. Repeat.

The wiper switch itself is very simple. Follow the FSM wiring. Generally it gets power, wiper motor connections, washer connection, wiper amp connections, and TCU connections. Stare at the FSM for a while and you will see how the wires line up and how the wires are connected depending on where the switch is at.

The washer is very simple. Power goes to the washer and then to the switch. When you pull the switch, it grounds the washer = squirt and it also triggers the TCU to swing the wipers 2 times for every squirt.


I know that's a lot but it can be simple if you just want a high speed switch with no auto return. It's annoying and doable if you don't mind moving the arms to where you want and then shutting it down with no auto retract help.

The washer is also very simple. You can just connect the washer ground wire to a switch and then ground.


Any questions? Don't ever say Zilvia is ignorant or don't want to help you out.


Wow man, that's a lot of great info...I'm sure I'll have to read it 3 or 4 more times til it completely sinks in, but thanks again!

PS - I've never said the people at Zilvia don't help, this is by far my favorite 240 forum, with a lot of very good people.

[TurboSE]

Fuse size is a function of the size of the wire. The size of the wire is a function of the total load you expect to pull on the circuit and the design of the circuit itself.

This is a whole different topic. There's no simple answer. It depends on your wiring diagram and how you run the wires.

Did you know that electrical engineers have problems with this issue?

I've been doing a lot of reading on this particular topic and have realized there is no cut-n-dry answer...something I'll have to figure out after all my circuits are wired. Thanks again!

[GSXRJJordan]

<333 this thread. You go G6. My question is, do you have a power window breakdown also? I'm trying to completely remove the SMJ, have already removed almost all of the fuse box circuits - but power window system and rear tail light setups still remain (but the tail lights are easy). Pm me if you've already done something similar, otherwise I'll have to do it myself :)

[TurboSE]

tre4s13 and surreybc, those diagrams are a lot better than the ones in my FSM, thanks a lot!

[TurboSE]

<333 this thread. You go G6. My question is, do you have a power window breakdown also? I'm trying to completely remove the SMJ, have already removed almost all of the fuse box circuits - but power window system and rear tail light setups still remain (but the tail lights are easy). Pm me if you've already done something similar, otherwise I'll have to do it myself :)

best of luck on the power windows, I was looking over that diagram in my FSM, doesn't look like something for the faint of heart. Thanks for all your help, and your S14 is very tight.

[g6civcx]

Hope this help, well it better...cause I JUST photoshopped it for you...

TCU.jpg - Image - Photobucket - Video and Image Hosting (http://s358.photobucket.com/albums/oo26/tre4s13/JustForYou/?action=view&current=TCU.jpg)

ImageShack - Hosting :: img0007ql9.jpg (http://img169.imageshack.us/my.php?image=img0007ql9.jpg)
ImageShack - Hosting :: img0029bj0.jpg (http://img169.imageshack.us/my.php?image=img0029bj0.jpg)

Thanks for posting pix, but these are way too complicated. Just look at the EL section of the FSM. It's very simple.

[g6civcx]

Wow man, that's a lot of great info...I'm sure I'll have to read it 3 or 4 more times til it completely sinks in, but thanks again!

PS - I've never said the people at Zilvia don't help, this is by far my favorite 240 forum, with a lot of very good people.

Tell me exactly what OEM function you want to keep and what OEM parts you want to re-use.

I'll tell you if it's possible, and if possible, how to do it.

[g6civcx]

<333 this thread. You go G6. My question is, do you have a power window breakdown also? I'm trying to completely remove the SMJ, have already removed almost all of the fuse box circuits - but power window system and rear tail light setups still remain (but the tail lights are easy). Pm me if you've already done something similar, otherwise I'll have to do it myself :)

What car is this for? I never know what car you be working on.

[GSXRJJordan]

What car is this for? I never know what car you be working on.

So true! It's a S14, but it's a 95, and I know it has a plug for the '95 window amp, so it should be the same as S13.

[g6civcx]

So true! It's a S14, but it's a 95, and I know it has a plug for the '95 window amp, so it should be the same as S13.

What do you want to do? If you're just trying to bypass the SMJ, why don't you just clip wires one at a time and reconnect them?

[GSXRJJordan]

*Blargh* Cause there's a billion wires that all share the same colors, and the SMJ is not 1:1 in and out, so as with all the other electrical subsystems (ECU power/Ignition power/lights/accessories) I'm making my own circuits one by one until I can rip the whole body harness out. So I'd like a standalone power window circuit, basically :)

[g6civcx]

*Blargh* Cause there's a billion wires that all share the same colors, and the SMJ is not 1:1 in and out, so as with all the other electrical subsystems (ECU power/Ignition power/lights/accessories) I'm making my own circuits one by one until I can rip the whole body harness out. So I'd like a standalone power window circuit, basically :)

I hear you, but if you pull the SMJ apart and look at the pins, you can tell which wires go where.

[surreybc]

So true! It's a S14, but it's a 95, and I know it has a plug for the '95 window amp, so it should be the same as S13.

the amp is the same as s13 but wiring is different than all other years.

[tre4s13]

tre4s13 and surreybc, those diagrams are a lot better than the ones in my FSM, thanks a lot!

No problem d00d, I even photoshopped it...so that it looks like I used a highlighter on it. =D

[TurboSE]

Tell me exactly what OEM function you want to keep and what OEM parts you want to re-use.

I'll tell you if it's possible, and if possible, how to do it.

In a perfect world, I would like to have a toggle switch to run the wipers on low, and a momentary button for the washer. I don't care if they return automatically...if they're on low, I can time it.

Otherwise...(and if it's significantly easier) the OEM functions and hardware is just fine for me.

In Pa, you need working wipers and washers to pass inspection...if I didn't, I'd leave them out completely since this won't be my daily.

Thanks again, g6civcx!

[g6civcx]

I would like to have a toggle switch to run the wipers on low, and a momentary button for the washer. I don't care if they return automatically...if they're on low, I can time it.


That's easy. All you need is the wiper motor. You can delete the wiper amp, the TCU, and the wiper switch.

On the wiper motor itself, wiring goes like this:

light green - put constant or switched current via a 20A fuse to this wire
orange - delete and tape off
black - connect to ground
light green/black - delete and tape off
light green/red - connect this wire to your switch. Make sure your switch is rated for at least 20A or higher. Then connect the other pin of the switch to ground.

On the washer motor, it's equally simple.

light green - 20A fused current, you can share this wire with the wiper motor's light green wire if you want to
pink - connect to your momentary switch, then to ground

Done! easy as pie.

[TurboSE]

Washer/Wiper (Low) w. Auto-Return?

http://memimage.cardomain.com/member_images/11/web/2243000-2243999/2243246_39_full.jpg?254504-314

[g6civcx]

Washer/Wiper (Low) w. Auto-Return?

http://memimage.cardomain.com/member_images/11/web/2243000-2243999/2243246_39_full.jpg?254504-314

Damn you. Why are you always changing stuff up?

That won't work. You're missing the wire to activate the wiper amp. On the stock wiper switch it's activated on OFF or INT.

See if you can figure it out first then I'll help you.

[TurboSE]

honestly...I am happy with the description you gave above...I tried to work it out with the return for myself. Trying to learn...

Thanks a million man

[TurboSE]

Washer/Wiper (Low)?

http://memimage.cardomain.com/member_images/11/web/2243000-2243999/2243246_40_full.jpg?031105-314

[TurboSE]

Damn you. Why are you always changing stuff up?

That won't work. You're missing the wire to activate the wiper amp. On the stock wiper switch it's activated on OFF or INT.

See if you can figure it out first then I'll help you.


Brown to ground on the toggle?

[g6civcx]

Washer/Wiper (Low)?

http://memimage.cardomain.com/member_images/11/web/2243000-2243999/2243246_40_full.jpg?031105-314

This will definitely work.

[g6civcx]

Brown to ground on the toggle?

You know there is an easier way to do this. You don't have to use the factory wiper amp.

Like I said above, you can use a standard 4pin relay. connect the orange wire to pin 85/86 and connect the other of 85/86 to fused current.

then connect light green/red to pin 37/87 and the other of 37/87 to ground.

when the orange wire shows ground, current will travel through the 86/86 pins and connect the 37/87 pins together = grounding the light green/red wire.

So any time orange shows grounds (wiper arms up), it will move the motor until the wipers are down.

Done.

[TurboSE]

I wasn't in love with the auto-return idea..even after I read, but I pulled out one of my relays and looked over it (I'm a visual kinda guy)...doesn't seem too bad. At least now I have a "Plan B" if I can't wire in the luxury of auto-return.

Many, many thanks g6civcx and everyone else that offered up ideas and solutions...

PS - Keep an eye out for future posts on how to wire RB/KA starting and charging systems!

[GSXRJJordan]

Great stuff in this thread. Zilvia rocks.

[g6civcx]

Great stuff in this thread. Zilvia rocks.

You know I am procrastinating on your window stuff. Yes, I am lazy.

[TurboSE]

You know I am procrastinating on your window stuff. Yes, I am lazy.

I don't blame you bro...I looked at the window diagrams and that is some scary stuff....Thanks again!

[TurboSE]

Here's my final answer:

http://memimage.cardomain.com/member_images/11/web/2243000-2243999/2243246_41_full.jpg?363901-321

[GSXRJJordan]

So you've got low, high, and "one swoosh" - does the "one swoosh" autoreturn without the timing unit?

[g6civcx]

Here's my final answer:

http://memimage.cardomain.com/member_images/11/web/2243000-2243999/2243246_41_full.jpg?363901-321

That should work. Just make sure you ground everything really well so you don't get ground loops. Pins 85/86 are really sensitive to a ground loop and can be annoying if you don't ground everything carefully.

[TurboSE]

So you've got low, high, and "one swoosh" - does the "one swoosh" autoreturn without the timing unit?

Just low with auto-return.

[TurboSE]

That should work. Just make sure you ground everything really well so you don't get ground loops. Pins 85/86 are really sensitive to a ground loop and can be annoying if you don't ground everything carefully.

Thanks a lot!

[TurboSE]

How about this for turn signal/hazard circuit. I want my turn signals to be able to function as hazards and vice versa...

http://i110.photobucket.com/albums/n112/TurboSE1980/TurnsignalHazard.jpg

[g6civcx]

How about this for turn signal/hazard circuit. I want my turn signals to be able to function as hazards and vice versa...

http://i110.photobucket.com/albums/n112/TurboSE1980/TurnsignalHazard.jpg

Oy, that won't work.

You need to figure out how the flasher relay works. Look in the FSM at the flasher relay section. It shows you how to test one. All flasher relays are the same.

One current, one ground, and one signal. When you put current to the relay, it will flash the signal.

Try again.

[TurboSE]

Oy, that won't work.

You need to figure out how the flasher relay works. Look in the FSM at the flasher relay section. It shows you how to test one. All flasher relays are the same.

One current, one ground, and one signal. When you put current to the relay, it will flash the signal.

Try again.

http://i110.photobucket.com/albums/n112/TurboSE1980/TurnsignalHazard.jpg