early 1972 heater fan switch (1 Viewer)

[franklin40]

i see that @ToyotaMatt has refurbished some of these switches and wonder if anyone knows a thread that would guide me through the process? or is this only something electrical gurus should attempt?

i have pulled the switch and can confirm my heater resistor is not the problem. the switch provides power when on high but not on low (the middle setting). i can connect the wire from the high and low setting on my heater (it’s an aftermarket flexalite heater) to the hight post on the switch and they both work. when connected to the middle/low setting there is no connection. i assume it’s something with the contacts in the switch.

i’ve searched and cannot find a threat that goes into switch details. just ones that lead to heater resistors

 

[Engineer8000]

There are spring loaded contacts and B-B in there so open it in a bucket or something if they go flying.

 

[Green Bean]

Those little bendy tabs have a tendency to break off.

 

[franklin40]

i’d like to know what they’re supposed to look when put together so if something does go flying i can put it back where it’s supposed to be!! if anyone has that info that’d be great

 

[franklin40]

Those little bendy tabs have a tendency to break off.

i saw matt’s had what looked like a clear shrink warp around them. i wonder if that why?

these are for a 73. mine are the older style with the “H” on the knob

 

[Green Bean]

I have the same older style. I ended up using heavy 3M loom wrap on the outside.

 

[charliemeyer007]

Go to an auto scrap yard. Pull out several dozen pull type heater/fan type switches. The local yard charged a buck to get in but anything you can fit in your pockets was free. Anyway take them apart and see how they work - learning the feel of a spring loaded ball detent is an acquired skill. It will transfer to other application like carbs. Having a clean, well lit work space is very nice. A big cardboard box with the open top covered in clear plastic and small hand ports cut in the side does a good job at catching flying parts

The little tabs are only good for 1 or 2 resets at best. A soldering iron to heat them up will help anneal them to some extent, before carefully prying the up just enough to release the unit.

 

[OregonOzzy]

@franklin40 no electrical guru here, just an average tinkerer. I did the exact same thing couple of weeks back since it was working on one speed most of the time. If you fiddled with the knob, you could sometimes get the slow speed to work. Dont have a write up but the pictures attached should help.

Nothing to be afraid of the tabs or the detent ball bearing. No parts were lost. Just be gentle when opening the tabs.

There are 4 tiny springs that keep up that copper "H" shaped plate. dont lose them. See the dirt on the contacts below:

The detent ball bearing is under that black plastic piece and it has a place for it (you will see when you open it up. I cleaned all the contact surfaces (3 nubs on the copper plate and the contact where the wires are soldered) with some emory board lying around, wiped it and put back together. Here are the 4 springs and the ball bearing has snuck out from its spot in the pic below:

Flipped over with the location of the ball bearing. Put it all back together being gentle to return the locking tabs to original position. Heater is working now at both speeds with no issues.

 

[franklin40]

that’s exactly what i need. k i’m gonna give this a try. not too complicated after all. i need my switch soon so don’t have time to go get a bunch out of a wrecker though that’s a good piece of advice. this i think i can do in the time frame i have to work with!!

 

[franklin40]

k so here we go!! i got it working.

gave the board a quick gently blast with the media blaster

then gently pry open the wire clamp followed by the 4 tabs. i tried to not just bend it by kinking the tab at its base but once it was lifted off the board i used a good set of needle nose pliers to actually straighten the tab. this will spread the bending stress over a longer area. this is the mucky mess inside

the brown plastic comes off the 5 pins so they can be cleaned up and sanded to remove corrosion. the copper plate can be removed to clean up the contacts. i forgot to get a picture but under the plate with the three contacts are three springs. the two black outer springs have the ball bearings under meath them. the centre shorter spring doesn’t. that’s all there is in there!! a good plant of electrical cleaner and time to reassemble.

now for the wiring.

the pull slides the 5 contacts over the 3 contact plate. the blue/red wire supplies power to the switch. the single sided post on the 3 contact plate will slide between posts to allow power in low or high.

the white blue will close the circuit when pulled fully out. the blue black with close the circuit in the middle position. with it pushed all the way in the power tabs don’t contact anything keeping the circuit open.

i’ll hook my power to blue/red, my low fan to the blue/black and my high to the blue/white.

do some reason my front heater has the high in the middle position and the low pulled
out fully. i wonder if wires got switched at the motor because they really can be screwed up at the switch due to the connectors

 

[ToyotaMatt]

@65swb45
@Green Bean
@73FJ40
@Engineer8000


i now add the clear non-adhesive OEM YAZAKI made in japan switch wrap to ALL my switches , seems like a good safety minded idea , and i like safe ideas .....


ONLY HAZARD had the Toyota factory installed stuff ,,,,,from the factory ....PLANT A11


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this kustom gal , was for @Curtice

i wonder if this was the first time , the OEM YAZAKI switch wrap was documented on motion media ?





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