ac blower switch repair

[aearch]

so my ac blower switch was really corroded from sitting around.
all green inside on the copper.
so you can take a small drill and ease the bottom edge that looks like a rivet,
actually its a small copper tube.
then tap out.
then clean up.
then set the bottom spring under the white plate and tape together to hold it in place.
you can bend it apart as the soldered connections are real strong.
then set the top part,
there are two springs and tension ball bearings.
set the smaller spring in the back and the larger toward the front.
then put the top back on and replace the copper rods.
then just jbweld the bottom edge to keep it in place
use some tape to keep it together while setting
test it before done w/ ohmeter -two pins one and 4 should i think have continuity
all done

 

[HB Chris]

Great pics Alan, they all need repair by now

 

[bill]

Thanks Aearch! I'll be taking mine apart next. How about the auxiliary fan? When will you do that? Are you going to tackle the cooling (evaporator) fan? Inquiring minds want to know, so I can start rehabbing my AC system.

 

[aearch]

had one in the shed go giants
so the bolt holding the fan is reverse thread
then tap out the fan
the rest is easy take out the 8mm bolts
and it comes right apart.
simple -clean and reassemble
solder wires if need be -
the anchor points are the soldered contacts.

 

[bill]

Took my switch apart today...Aearch it isn't quite as easy as you said. Once the 4 copper "tubes" come out, the whole assembly will fall apart if you don't hold everything together. The "top" of the switch, where the rheostat is, is easy enough to take apart, it's a little difficult to clean the copper ring the wiper pivot rides on, but pretty straight forward. The "bottom" assembly comes apart very easily and care is needed here because there are THREE springs that will fall out, two for the ball bearings, and another for the switch mechanism that lives in there (the triangular-shaped plate is tensioned by a spring; the switch disconnects the heater fan when the AC is on.) Very fiddly old-world assembly, but it is great to be able to take it apart and clean it. Thanks for the aux fan pix....that looks like a piece of cake.

 

[aearch]

yep so first set the lower spring assembly and hold it together with scotch tape then the top goes
together easy
One thing about the fan motor
you might want to check and make sure the magnets are secured well
mine were loose so i reset them with jb weld quick
If they are loose just make sure you put them back so the bolts can still
go thru.

 

[Drew Gregg]

so my ac blower switch was really corroded from sitting around.
all green inside on the copper.
so you can take a small drill and ease the bottom edge that looks like a rivet,
actually its a small copper tube.
then tap out.
then clean up.
then set the bottom spring under the white plate and tape together to hold it in place.
you can bend it apart as the soldered connections are real strong.
then set the top part,
there are two springs and tension ball bearings.
set the smaller spring in the back and the larger toward the front.
then put the top back on and replace the copper rods.
then just jbweld the bottom edge to keep it in place
use some tape to keep it together while setting
test it before done w/ ohmeter -two pins one and 4 should i think have continuity
all done

Thanks for the info. Just talked to the previous owner who told me the switch only worked on "High" while he had the car.---Drew

 

[dhanna]

This is amazing!
any updates on how well it works/ is it still working 4 years on?
What resistance range we should be seeing on the rheostat?
How do you protect the copper in the switch from corroding again? Can I use dielectric grease like on my spark plugs?
I have a bead on an NOS switch that I'd be willing to purchase and attempt this on.
sorry for the 20 questions guys.

 

[HB Chris]

If you find a NOS one be aware they changed in 74 models with an additional post for wiring, early has four pins, 74 has five pins. I slipped a piece of sand paper in mine to clean the contacts. If the spring isn’t making good contact then it needs to come apart which I have by never done.

 

[aearch]

dont buy another it will be as yours is now in time
do the repair

 

[Luis A.]

Deoxit D5 contact cleaner spray works well for the rheostat as well as any other 40+ year old electrical connection/contact points.