Cleaning electrical switch.

[meirman]

This is about about my car heater fan. It's not really about home or electronics repair, but I think you will be able to help me, and I'd appreciate it.

Can I regrease my electric switch? And if so, what should I use to remove the old grease? And more importantly, what sort of grease should I then use to regrease this 12 volt switch?

I have white grease, lithium grease, ball joint etc. grease (in a grease gun), some wheel bearing grease, "bicycle" grease in a tube by Schwinn, and maybe one more kind. I even have Crisco. Or I can buy something new.

My '95 Chrysler heater/AC fan speed switch no longer works in position 2, the one I use most often. A new replacement is very expensive**. I'm told the other speeds will fail soon.

With the switch dissassembled, it looks fine. There is some old grease on the contacts, now darker than new, but was brown and shiny when new. It is now, at least on the surfaces of the grease, a little bit harder than new, but when I push aside the grease with a wooden match stick stem, the copper contact underneath shows no burning or anything unusual. It's not as shiny as new, but I didn't think that would matter, since I'm sure the other three speeds aren't either.

I thought just mixing up the grease would be enough, and sure enough, the meter had shown infinity but now showed almost zero resistance, well under an ohm.. After reassembly it still tested good (with the low current used by meters) but after reinstallation, again the second position of the switch didn't work, not enough to power the fan (though the separate resistor that is used to lower the voltage to get a lower than max fan speed.)

**The switch is not sold separately and a whole new control panel costs 150 or 250 dollars. If I buy from a junkyard, I'm told it will probably already not work for the same reason mine doesn't.

What should I do?

Thanks for any help.

Meirman

 

[Bennett Price]

I'm no expert but I'd remove all the grease from the copper contacts, (use alcohol, kerosene, gasoline, paint thinner, whatever, electrical contact cleaner in a spray can but not WD40, even soap and water). Grease (white) should go on the mechanical detents but not on the copper contacts; they should remain dry.

Perhaps you can somehow bend the wiper a bit so it makes firmer contact with all the positions (and the second in particular.)

 

[Tony Hwang]

This is about about my car heater fan. It's not really about home or electronics repair, but I think you will be able to help me, and I'd appreciate it.

Can I regrease my electric switch? And if so, what should I use to remove the old grease? And more importantly, what sort of grease should I then use to regrease this 12 volt switch?

I have white grease, lithium grease, ball joint etc. grease (in a grease gun), some wheel bearing grease, "bicycle" grease in a tube by Schwinn, and maybe one more kind. I even have Crisco. Or I can buy something new.

My '95 Chrysler heater/AC fan speed switch no longer works in position 2, the one I use most often. A new replacement is very expensive**. I'm told the other speeds will fail soon.

With the switch dissassembled, it looks fine. There is some old grease on the contacts, now darker than new, but was brown and shiny when new. It is now, at least on the surfaces of the grease, a little bit harder than new, but when I push aside the grease with a wooden match stick stem, the copper contact underneath shows no burning or anything unusual. It's not as shiny as new, but I didn't think that would matter, since I'm sure the other three speeds aren't either.

I thought just mixing up the grease would be enough, and sure enough, the meter had shown infinity but now showed almost zero resistance, well under an ohm.. After reassembly it still tested good (with the low current used by meters) but after reinstallation, again the second position of the switch didn't work, not enough to power the fan (though the separate resistor that is used to lower the voltage to get a lower than max fan speed.)

**The switch is not sold separately and a whole new control panel costs 150 or 250 dollars. If I buy from a junkyard, I'm told it will probably already not work for the same reason mine doesn't.

What should I do?

Thanks for any help.

Meirman

Hi,
Usually the speed is controlled by seiries resistor with taps. Actually the switch itself is changing the position of tap. Tried local wrecking yard? Hard to believe #2 position contact is worn to a point of high resistance with high current. Maybe something wrong with wiring harness?
Tony

 

[meirman]

In alt.home.repair on Sat, 21 May 2005 22:37:09 GMT "Joseph Meehan"

Thanks for replying.

That is the answer to your question. It is not the switch that is bad, it is a resistor that is gone. They tend to fail one at a time.

Thats what I thought at first, but

a) The switch tested bad in the second position only.

b) A friend gave me a control panel from a Chrysler Caravan truck that he was scrapping**. The second fan speed, all the fan speeds work fine with his control panel. (I can't just take the fan speed switch from it because it won't fit in my heater control panel. And I can't use his control panel because almost all the connections are different in his control panel. The vacuum hoses are longer, not a problem; the electrical connection might be in the same place; but the hot/cold door control cable connects at the left rear corner instead of right rear, and is meant to come in at a 90 degree different angle. I tried to find some slack in the cable, but there isn't. (It's very hard, almost too short, even to connect the cable to the control panel it was designed for.)

The speed is controlled by the resistors, but if the switch is bad, then no current will reach the intended place on the resistor pack.

**Same year and same appearance on the front of the control (except my dim white letters and lines were bright white on his.) but behind the face plate, a different style of control panel. Everything rearranged.

On some cars the resistors are built into the switch and in others there is a separate resistor pack. You need to replace what ever has the resistors in it. I don't recommend trying to replace the resistor, just buy the pack or switch.

Note: Often this happens when the blower fan motor is starting to wear out. If it were mine and unless it is easy to get to that resistor pack, I

Actually, the resistor pack is rather hard to get to, but the bigger trouble was that I loosened the screws for a long time, but neither came out. Couldn't see the other side. But like I say, it works with my friend's switch.

would replace the motor and the resistor pack. If you can get to the resistor pack easily, and you can on some cars, I might try just that, but I suspect you will find it going out again in a matter of months.

Meirman

 

[George E. Cawthon]

This is about about my car heater fan. It's not really about home or electronics repair, but I think you will be able to help me, and I'd appreciate it.

Can I regrease my electric switch? And if so, what should I use to remove the old grease? And more importantly, what sort of grease should I then use to regrease this 12 volt switch?

I have white grease, lithium grease, ball joint etc. grease (in a grease gun), some wheel bearing grease, "bicycle" grease in a tube by Schwinn, and maybe one more kind. I even have Crisco. Or I can buy something new.

My '95 Chrysler heater/AC fan speed switch no longer works in position 2, the one I use most often. A new replacement is very expensive**. I'm told the other speeds will fail soon.

With the switch dissassembled, it looks fine. There is some old grease on the contacts, now darker than new, but was brown and shiny when new. It is now, at least on the surfaces of the grease, a little bit harder than new, but when I push aside the grease with a wooden match stick stem, the copper contact underneath shows no burning or anything unusual. It's not as shiny as new, but I didn't think that would matter, since I'm sure the other three speeds aren't either.

I thought just mixing up the grease would be enough, and sure enough, the meter had shown infinity but now showed almost zero resistance, well under an ohm.. After reassembly it still tested good (with the low current used by meters) but after reinstallation, again the second position of the switch didn't work, not enough to power the fan (though the separate resistor that is used to lower the voltage to get a lower than max fan speed.)

**The switch is not sold separately and a whole new control panel costs 150 or 250 dollars. If I buy from a junkyard, I'm told it will probably already not work for the same reason mine doesn't.

What should I do?

Thanks for any help.

Meirman

I'm with the others-- it isn't the switch. Now
that you've got the switch apart, I suggest you
just stir up the grease as you did. If you want
to clean it, spray it with WD-40, then regrease
with a silicone grease-- bicycle grease would be
great.

I go along with Meehan that it is the resistor.
If there are separate coils in the fan motor to
change speeds, a coil could be burned out, but
that isn't likely.

 

[George E. Cawthon]

I'm no expert but I'd remove all the grease from the copper contacts, (use alcohol, kerosene, gasoline, paint thinner, whatever, electrical contact cleaner in a spray can but not WD40, even soap and water). Grease (white) should go on the mechanical detents but not on the copper contacts; they should remain dry.

Perhaps you can somehow bend the wiper a bit so it makes firmer contact with all the positions (and the second in particular.)

Grease is commonly used in high amp switches to
reduce contact burning/arcing. Removal of the
grease will lead to a short life.

 

[Robert Barr]

The OP has already said he's tested the switch and found that position #2 isn't functional (continuous), while the others are. I'd say it's likely the guy knows how to use a meter, and therefore it's the grungy contacts (and maybe degraded spring force) that are to blame.

I had an identical problem with a Volkswagen fan switch. I found the contacts all green & crumbly from corrosion. I cleaned the contacts using Flitz, sprayed it down with contact cleaner (Chem-clean, I think) and reinstalled it. It worked fine from then on, for about 8 years.

I'd say avoid any lubricant at all. Just polish the contact areas & reassemble.

 

[electricitym]

come on now..... if there wasn't supposed to be grease in there, why would the manufacturer put it in there to start with. Even in low amperage switches like "mode switches" in VCR's they put grease in there to not only reduce the friction and wear but to keet the contacts from oxidizing..... put grease in there for sure.... even a heavier general purpose grease would be just fine for the higher amperage and heavier contact spring tension switch like in the heater fan switch. If you run it dry, you will lose the switch in a much shorter time. electricitym ..
..

 

[quietguy]

This advice does not seem appropriate to me - grease on the switch contacts is NOT a good thing - a little grease on the rocker is OK, but only there.

I would suggest cleaning the contacts with CRC, apply a little high melting point grease (silicon?) to the rocker bearing surface, and reassembling.

David

 

[quietguy]

Maybe, but I doubt it. My thoughts are that due to arcing etc the grease that lubed the switch mech has melted and flowed to the contacts, casuing more arcing etc etc

As far as I know grease is an insulator, not a conductor

David

 

[w_tom]

Obviously you 'feel' a grungy contact is not good. It's called being an old wife and promoting tales. It's dirty.
Therefore it must be bad.

As posted previously by others, that grease heavy on
contacts is there for good engineering reason. First learn how contacts make and break electricity before just wildly speculating. But to make it simpler to understand: remove grease on those contacts to make switch fail fast.

Stop 'feeling' a conclusion. Stop using old wife
reasoning. Or even better, first buy new switches, break them open, and learn before posting. Or read the informed post by George E. Cawthon. High current contacts require a heavy glob of grease (or something equivalent) to last. Did you also know there are two types of switches and relays? Some that can break a current. Others that can only be switched when no current flows. Only the naive would assume 'dirty' means 'bad' - just like myths from an old wife.

 

[w_tom]

My post was about people who 'feel' rather than first learn facts. For some reason, Red Cloud has decided to use himself as a perfect example. He immediately 'feels' I was discussing dielectrics. Of course I was not. But then he knows because he 'feels' that is what I must have been thinking. So why does Red Cloud do this? Just another name and reason to insult others. His name?

Red Cloud® posted using numerous names including
BinaryBillTheSailor@Sea++.com, Ekal Bnek, MaximumSmoke, and . One poster even speculates that BinaryBill also posted using the name Ken Blake. He has been accused by Sirius, VWWall, Thor, etc of using pseudo names. In a discussion entitled "Computer Fire Starts Flame War" in alt.computer, others bluntly ask him (whoever he really is) what his alter egos would think. Previous posts by BinaryBill
- now Red Cloud® - of insults are cited in that alt.computer discussion at:
http://tinyurl.com/bjk8e

He even claimed to work with Grace Hopper on the original computer called Eniac in the 1940s. Therefore he must know something... about twisting the truth.

 

[George E. Cawthon]

Maybe, but I doubt it. My thoughts are that due to arcing etc the grease that lubed the switch mech has melted and flowed to the contacts, casuing more arcing etc etc

As far as I know grease is an insulator, not a conductor

David

I suggest you open and look at a few switches,
especially older ones that are designed to be
repaired.

 

[meirman]

In alt.home.repair on Sun, 22 May 2005 22:39:37 GMT Red Cloud® posted:

Okay, then, w_tom, please show me, and everyone else, where you specified what type of grease should be used in a switch, and it's characteristics. You can't.

You have a very long and colorful history in usenet of posting lengthy technical answers that contain enough true information to make them seem believable, but then you go further and add stuff that is completely and scientifically unsupportable.

You have used this technique for years to post advice, which if followed, could easily cause injury or death. I'm far from being the only one to point this out. Due to the danger of your posts, I've collected a few over the years, including responses of other very knowlegeable and sane people showing why you are so dangerous. Shall I start posting a few of them?

So, where did you say what kind of grease to use? I'll be waiting, troll.

rusty redcloud

Well, I'm sorry to have started something that led to a fight.

My understanding of wtom's first post was that it was just meant to contrdadict the poster before him who said that grease was bad. I don't think wtom recommended any specific good grease, but I also don't think he said any old grease would be all right.

And there was no need for wtom to suggest a grease, because 5 hours earlier in the same subthread, Joseph had suggested a conductive grease from the autoparts store.

Meirman

 

[meirman]

In alt.home.repair on Sun, 22 May 2005 10:38:25 GMT "Joseph Meehan"

That would be the case if the resistors were integrated in the switch.

True, but they're not. They're under the dash, below the glove compartement, with the resistors themselves in the air duct from the outside. I think that is to help cool the resistors, which in my GM cars were just wire coils suspended in air, with no non-conductor surrounding them.

Have you established that there is a separate resistor pack? (It is often located in the cool air stream to help cool them)

LOL. I just said that!

Assuming it is the switch, I would suggest replacing it rather then trying to fix it. I have never need a car switch that was going to be easy to fix. Be sure to use a the special grease made to electrical contacts if you decide that is needed.

Meirman

 

[meirman]

In alt.home.repair on Sun, 22 May 2005 10:40:55 GMT "Joseph Meehan"

The CRC would be good, You want to get all that WD-40 or whatever out of there, followed with some real contact grease. Most auto shops carry it today in small tubes for "lamps and connections"

Didn't know that. Good idea. That's another place I've seen grease, you remind me. Inside lamp sockets, those that face tghe outside, like turn signals.

Since that is not the usual case with these sockets, maybe the grease is added to lamp sockets when there is water present that the mechanic can't stop. ????

As to the heater switch, I did note during testing today that between speeds 1, 2, 3, and 4, it makes the connection with the next speed setting before it breaks the connection with the current one. Seems to me this should cut down arcing to zero or near zero. Except between off and speed one, which is the lowest speed using the least current. Of course the design must not be as good as I'm making it sound, or these things wouldn't be breaking all the time. (The model from my friend's van may be the more recent one, and maybe it doesn't fail like the old one did. Still, cars have had heater fans speed switches since 1950 and earlier, and one would think they'd have the bugs out by now. My car only has 76,000 miles.

I apologize but I may not have to regrease after all, and I won't if I don't have to because I don't want to open the switch more times than necessary, and break the metal tabs that hold the switch together.

I tested it today with the heaviest 12 volt load I had handy today, and that was a diaphragm-style air compressor suitable for refilling flat tires. Nowhere near, I think, as big a load as the fan, but it worked fine, and I couldn't even hear a difference in speed from the other switch positions. (I wasn't using any resistors.) If I had had 10 more minutes, I could have installed the fan (if I didn't connect the hot/cold lever) but something came up.

Meirman

 

[electricitym]

You obviously DO NOT want a "conductive" grease in the switch.... it would obviously short it all out... a standard silicon or petroleum grease works great to lube the contact and helps it from oxidizing and pitting. The higher amp rating of the switch, the heavier contact pressure, the heavier the grease. electricitym ..
..

 

[electricitym]

The best contact cleaners for many switches and pots contain a (non-conductive) lubricant that is left behind.... this protects the contact from rapidly oxidizing and pitting. In the old rotary TV tuners..... which contains multiple switch wiping contacts, a lubricating contact cleaner was always used for smooth, reliable, and long lasting repair. You obviously DO NOT want to use a CONDUCTIVE grease.... this would short everything out in a switch or pot. A light grease is used for smaller low current applications and a heavier grease is used for higher current applications. Silicon greases are good but also many petroleum based greases can be used. electricitym .. ..
..

 

[meirman]

In alt.home.repair on 22 May 2005 18:53:54 -0700
posted:

You obviously DO NOT want a "conductive" grease in the switch.... it would obviously short it all out... a standard silicon or petroleum

My gosh, you're right. I might have thought of this when I was reading the label. Thanks.

grease works great to lube the contact and helps it from oxidizing and pitting. The higher amp rating of the switch, the heavier contact pressure, the heavier the grease. electricitym .
.

Meirman

 

[George E. Cawthon]

meirman wrote:
((snip))

As to the heater switch, I did note during testing today that between speeds 1, 2, 3, and 4, it makes the connection with the next speed setting before it breaks the connection with the current one. Seems to me this should cut down arcing to zero or near zero. Except between off and speed one, which is the lowest speed using the least current. Of course the design must not be as good as I'm making it sound, or these things wouldn't be breaking all the time. (The model from my friend's van may be the more recent one, and maybe it doesn't fail like the old one did. Still, cars have had heater fans speed switches since 1950 and earlier, and one would think they'd have the bugs out by now. My car only has 76,000 miles.

Boy are you optimistic! I've had older cars most
of my life, getting them at 50,000 miles or so
(5-10 years old)and getting rid of them at over
100,000 (12-29 years old). Only recently have I
ever had a problem with a heater switch. It was a
car 9 years old with about 40,000 miles on it.

I apologize but I may not have to regrease after all, and I won't if I don't have to because I don't want to open the switch more times than necessary, and break the metal tabs that hold the switch together.

I tested it today with the heaviest 12 volt load I had handy today, and that was a diaphragm-style air compressor suitable for refilling flat tires. Nowhere near, I think, as big a load as the fan, but it worked fine, and I couldn't even hear a difference in speed from the other switch positions. (I wasn't using any resistors.) If I had had 10 more minutes, I could have installed the fan (if I didn't connect the hot/cold lever) but something came up.

Glad to hear the switch is working, now to find
out if that was really the problem.