What does this do? (with a twist) FJ40 Wiper Motor *warning electrical voodo contnent

[Stumpalama]

So, what does the part circled in red do on the wiper motor to the left? The Australian one is straight wired to the common brush.



The story: I am working on modifying my US wiper to run with an Australian 4X wiper switch and intermittent mechanism. I'm fairly certain I have the wiring correct. The US wiper is identical to the AUS one (except the AUS one mounts on the left and can't be mounted on LHD trucks). I reconfigured the US motor mounted wiring to be identical to the AUS one. The problem is the US one will not energize when power is put to the wiper (the AUS one does). The only difference I can figure is the mechanism on the US motor.

Thanks for the help!

 

[myquestoyota]

Maybe with a picture someone could know what is circled? I would love to have intermittent wipers and a stock look.

 

[Stumpalama]

I may have answered my own question after reviewing the schematics in my shop manual... for the 500th time.

The diagrams appear to show the 60's and AUS rigs use a negative ground to complete the common leg of the circuit where US 40's use positive ground by having the common leg return to the switch to ground.

Does this sound feasible?

 

[chevurai]

Yes. There is power to the wiper motor and when the switch is turned on it completes the ground and the wipers turn on.

 

[Stumpalama]

Yes. There is power to the wiper motor and when the switch is turned on it completes the ground and the wipers turn on.

So, by grounding the common leg to the motor housing and having power come in from the switch (that's how the AUS switch is wired) converts a + ground circuit to a - ground circuit, correct?



I just soldered a wire from the common motor brush, bridged the circled doohickey to ground to the housing. This is poorly represented by the black squiggly line.

Anyone else have insight into the doohickey or my wiring theory?

 

[StaleAle]

That appears to be the intermittent switch that shorts the circuit when you turn off the wipers; turning your motor into a generator of sorts for a brief instant to provide sufficient power to park the wiper blades.

Professor Morthimer could provide some guidance on wiring this in if you need it.

 

[Jakes40]

x2
I think its the blade parker.

 

[StaleAle]

When you talk to Ed, be prepared to gain enlightenment on the electrical properties of a collapsing elect-magnetic field.

 

[Fey1]

On mine, the 'home' switch is mounted to the gear box. If this one with the part in question is off of an 'intermittent' wiper assembly, It's possible that it is the switch that controls the wire timing. The photo is not really good enough to tell. (Can you get a better photo/close up from a slightly angle?)

 

[Henry James the 47th]

I can post a couple of pics of the critter:

 

[myquestoyota]

Boy, if you figure this out do a specific thread on how and what parts to use. Here in the NW intermittent wipers are almost as necessary as fog lights. (I need to put some of those on too)

 

[Stumpalama]

Thanks for the pic HJ.

Well, I got it to cycle in hi, lo and intermittent, but blew a fuse on the constant hot to the wiper motor trying to figure out which wire goes where. It was to dim to ID the culprit (no power too the workshop...yet) so I only had hi and it wouldn't park the wiper when shut off.

Is the mechanism in question really the park function? In the FSM it references a cold weather breaker and this seems to resemble something that would possibly connect when warmed by electrical current and connect. I ask because the RHD motor does not have this mechanism, tho I didn't hook it up as a control subject. If it is in fact the wiper park mechanism, I'll need a new motor since this one got pooched when the top connector got bent back by my stupid meat hooks.

 

[Henry James the 47th]

The thing is, if it is a wiper park mechanism, then surely the Aus-spec motor would also have the parking function, no?

I presume you have the intermittent wiper relay. I'm looking forward to seeing this problem get licked!

 

[Stumpalama]

OK, I believe the park mechanism is the gear with the 3 connectors soldered on the outside. the gear on the inside is a combination of exposed plastic and metal. It appears that the power is shut off, the constant hot runs the motor until the gear comes around to a section with plastic is exposed.

I think the mechanism in the pictures is the cold climate breaker.

 

[StaleAle]

Close-up pic doesn't look like the park switch on mine so I think you are correct.

 

[Stumpalama]

It worked! I successfully converted the motor to a positive ground motor. It is straight forward (as long as your wiring under the dash is still the same as stock).
To add stock intermittent wipers you'll need an intermittent wiper relay box from an FJ60 and a 3 position switch, most likely from a late model Australian FJ or HJ 4X.

 

[Henry James the 47th]

Did you wire it just as you indicated on the above photo, bridging the cold weather switch and connecting to the motor housing/ground? Did you take any pics?

 

[Stumpalama]

HJ: yes, I did and yes, I did, I just have to get them off the phone. Feels funny typing get my pic off a phone.

 

[Henry James the 47th]

I look forward to the pictures. Any worry about problems in cold weather?

 

[Henry James the 47th]

In the FSM it references a cold weather breaker and this seems to resemble something that would possibly connect when warmed by electrical current and connect.

In which manual did you see this? I have a factory 1981 40 and 55 series manual, but no circuit breaker is shown associated to the wiper motor. Another 1981 Toyota manual I have for 40 and 60 series only shows the 60 series wiper motor, and there is a note about the characteristics of the cold weather circuit breaker.

I've long wondered if there is a factory 40 series manual showing some of the minor changes in the 1982~84 range, like the wiper switch with intermittent....

Looking in the 1981 40~60 series manual at the fold-out wiring diagram sheets, I note wiring differences shown between the BJ40, BJ43, and HJ47 sheet and the sheet for BJ40 (for USA and Canada).

The upper picture is for BJ40 (for USA and Canada, the lower for BJ40, BJ43, and HJ47 - note, among other things, the difference at terminal 'E' on the motor in terms of how the wiring is treated, and the differences in the switch internals: