L300 Combination Switch.
Posted: Mon Jul 18, 2011 12:00 pm
Like a lot of things in life, it happened suddenly and it came out of left field. I was driving to Jay & Christine's, east on the No.1 just west of the Kensington Exit when I smelled what first seemed like hot brake shoes. The first thing I did was check my E-brake, it was disengaged. My next thought was that the smell came from a car up front so I turned the fan off ~ the smell stopped. I passed Kensington and the traffic had changed in front of me so I put the fan back on ~ there was the smell again. My imagination started to get more creative, was it the A/C? Was that glycol I was smelling? I got to the backyard of the Tardis Hotel, switched the engine off and got out of the wagon. As I said hello I realised that the lights were still on. I thought: "Silly man, you didn't turn the lights off" and went back to the van ~ the switch was off? At this point Jay says "Oh no, I've seen this before, you have to pull the fuse, it's your combination switch ~ it happens to these vehicles". So I pulled the fuse and started to worry. Apparently the smell of fusing plastic was in the van all the time, the fan was just blowing it to my nose!
I must interject here, I would like to comment on Jay's character: Jay's behaviour is exemplary and I wish more people would follow it. He is one of the most generous and caring people I have ever met and it is truly an Honour to know him.
Fortunately, Jay had a broken combination switch in his work shop that I was able to cannibalise with what was not broken on mine. This, incidentally, is really good practise for survival in zombie world. When I first looked at the switch all I saw were many multi coloured wires soldered to PC boards and it was, quite frankly, intimidating. So I looked closer and this is what I found: It is a simple switch, complex in style but simple, non the less. The images in this posting were taken with cel phones in dubious light conditions, my apologies for poor quality.
There is a small carriage that slides back and forth. It is controlled by a little thingy that is controlled by the rotating switch at the end of your wand. It turns the running lamps and the headlamps on and off. When you turn the switch at the end of the wand, the little thingy at the other end of the shaft pushes the little carriage back and forth. The little carriage has two copper contacts that connect to the contacts on the back of the relevant PC board. They look like this:
Now you can see in the picture that what has happened is the contacts have gotten dirty over time, this dirt has helped to generate arcing (as indicated by the burn marks). In my case the arcing caused the switch carriage to fuse to the body and the wand pivot to do the same, which was the smell I experienced whilst driving. Let's look at the wand:
As you can see the wand has a protruding ring, on the end of the ring is a tube that holds a spring and a ball bearing. As you move the wand to make a signal the ball bearing goes over bumps in the track. The pivot for the wand is under the metal plate, close to the switch carriage, which is why it got fused, as well, in my experience.
When the fusing happened it changed the molecular structure of the contact plate ~ it was no longer copper but had become a new alloy, created by heat.
There is a magic coating that goes on these contacts. This coating does a number of things:
Here is what I did:
First I had to get to the contraption in the first place. Underneath the steering wheel, by your lap as you sit in the seat is a small Phillips screw; this secures the horn control to the top of the wheel, you need to undo that first. Once that is out of the way, you push/lift the horn control forward, like this:
You see the tab with the hole is where the screw goes in; the two forward tabs secure the unit via fixed leverage. Next, the wheel has to come off. This is done by removing, I believe is a 17mm nut (if it is not I'm sure you can work it out):
Now that that is away you need to mark the position your wheel is at so you can put it back in the same direction on the spline:
The wheel should slide off. I have heard that some people have experienced difficulty in removing the wheel, I have found that by not trying too hard it comes off easier. This is what you should see next:
Next you must remove the casing about the steering column; this involves six Phillips screws from the underside:
The under piece should fall off. For the top piece to come off requires the steering column to be in the down position, which is done by moving this lever:
Now we get to the combination switch. To get it off so we can work with it you need to remove two screws:
Now they are removed, gently pull the switch unit off of the steering column and turn it upside down. here are two more screws and a plastic clip to disconnect:
Next is the contact plate which is held on by three screws and a "tongue in slot" arrangement. This plate reveals the switch carriage and contact plate. Note the "tongue" at the top of the plate in the second picture:
The switch carriage comes out easily (when it's not welded to the body) and looks like this. Beneath it you will see the "thingy" that moves it back and forth:
This is where the magic starts. I found this product called "Deoxit" at RP Electronics on Rosser Street, in Burnaby. It comes in different formulas ~ get the 100% concentrated version. This diminutive tube cost me nine bucks:
You administer the "Deoxit" to the contacts. As I mentioned earlier it is a cleaner, you need to clean the gunge from and around the contacts. Having done that I re-administered the product and let it dry. It doesn't take a lot:
Then you put it all back together again and drive along your merry way!
Will this help you in your particular situation? I'm not sure. I think this will help a little, 'though ~ This experience has be very enlightening, to say the least. It also has given me a sense of ability and achievement. I did it! And... I got out of the Tardis Motel backyard around two in the morning. I really must extend my heart felt gratitude to Jay who was near by or actively working with me. You are a good teacher, Jay, and a good friend.
Falco.
I must interject here, I would like to comment on Jay's character: Jay's behaviour is exemplary and I wish more people would follow it. He is one of the most generous and caring people I have ever met and it is truly an Honour to know him.
Fortunately, Jay had a broken combination switch in his work shop that I was able to cannibalise with what was not broken on mine. This, incidentally, is really good practise for survival in zombie world. When I first looked at the switch all I saw were many multi coloured wires soldered to PC boards and it was, quite frankly, intimidating. So I looked closer and this is what I found: It is a simple switch, complex in style but simple, non the less. The images in this posting were taken with cel phones in dubious light conditions, my apologies for poor quality.
There is a small carriage that slides back and forth. It is controlled by a little thingy that is controlled by the rotating switch at the end of your wand. It turns the running lamps and the headlamps on and off. When you turn the switch at the end of the wand, the little thingy at the other end of the shaft pushes the little carriage back and forth. The little carriage has two copper contacts that connect to the contacts on the back of the relevant PC board. They look like this:
Now you can see in the picture that what has happened is the contacts have gotten dirty over time, this dirt has helped to generate arcing (as indicated by the burn marks). In my case the arcing caused the switch carriage to fuse to the body and the wand pivot to do the same, which was the smell I experienced whilst driving. Let's look at the wand:
As you can see the wand has a protruding ring, on the end of the ring is a tube that holds a spring and a ball bearing. As you move the wand to make a signal the ball bearing goes over bumps in the track. The pivot for the wand is under the metal plate, close to the switch carriage, which is why it got fused, as well, in my experience.
When the fusing happened it changed the molecular structure of the contact plate ~ it was no longer copper but had become a new alloy, created by heat.
There is a magic coating that goes on these contacts. This coating does a number of things:
- It cleans the surface of the contact.
- It enhances the connexion.
- It also reduces or stops the arcing between the contacts.
Here is what I did:
First I had to get to the contraption in the first place. Underneath the steering wheel, by your lap as you sit in the seat is a small Phillips screw; this secures the horn control to the top of the wheel, you need to undo that first. Once that is out of the way, you push/lift the horn control forward, like this:
You see the tab with the hole is where the screw goes in; the two forward tabs secure the unit via fixed leverage. Next, the wheel has to come off. This is done by removing, I believe is a 17mm nut (if it is not I'm sure you can work it out):
Now that that is away you need to mark the position your wheel is at so you can put it back in the same direction on the spline:
The wheel should slide off. I have heard that some people have experienced difficulty in removing the wheel, I have found that by not trying too hard it comes off easier. This is what you should see next:
Next you must remove the casing about the steering column; this involves six Phillips screws from the underside:
The under piece should fall off. For the top piece to come off requires the steering column to be in the down position, which is done by moving this lever:
Now we get to the combination switch. To get it off so we can work with it you need to remove two screws:
Now they are removed, gently pull the switch unit off of the steering column and turn it upside down. here are two more screws and a plastic clip to disconnect:
Next is the contact plate which is held on by three screws and a "tongue in slot" arrangement. This plate reveals the switch carriage and contact plate. Note the "tongue" at the top of the plate in the second picture:
The switch carriage comes out easily (when it's not welded to the body) and looks like this. Beneath it you will see the "thingy" that moves it back and forth:
This is where the magic starts. I found this product called "Deoxit" at RP Electronics on Rosser Street, in Burnaby. It comes in different formulas ~ get the 100% concentrated version. This diminutive tube cost me nine bucks:
You administer the "Deoxit" to the contacts. As I mentioned earlier it is a cleaner, you need to clean the gunge from and around the contacts. Having done that I re-administered the product and let it dry. It doesn't take a lot:
Then you put it all back together again and drive along your merry way!
Will this help you in your particular situation? I'm not sure. I think this will help a little, 'though ~ This experience has be very enlightening, to say the least. It also has given me a sense of ability and achievement. I did it! And... I got out of the Tardis Motel backyard around two in the morning. I really must extend my heart felt gratitude to Jay who was near by or actively working with me. You are a good teacher, Jay, and a good friend.
Falco.
