Sparton Horn Question - with pictures

[sconnors]

While wiring my new headlight harness, I took my horn apart and noticed that one side of the windings are copper while the other side is black? Is this normal? I also included several other pictures of the horn. The reason I ask is that after I had the new wiring harness in and connected the horn cover and turned the power on the horn stuck on. I got it to stop by loosening the cover. It worked and then stopped so I decided to take it apart and check it out and clean and this is what I found.
Any ideas or input would be greatly appreciated.

[Bob C]

If the screw that hold the back cover on it to long it can
touch the brush holder on the side with the burnt windings.

Bob

[Tom Wesenberg]

The original cover screw is only threaded for a short distance, so you can't screw it in too far. If you use some other screw, it may get screwed in so far it touches the motor brush holder, which will make the horn blow.

Smell each winding to see if it's actually burnt. I've seen dark and light enamel used on copper wire, and one coil may have been replaced. I put a light coat of grease on the wavy wheel.

A good working horn should draw about 5 amps.

[700rpm]

If it's original, I'd clean the rust off the diaphragm and apply a thin coating of light oil to stop further deterioration. I haven't found a repro diaphragm that worked properly.

[sconnors]

Originally Posted by Tom Wesenberg

The original cover screw is only threaded for a short distance, so you can't screw it in too far. If you use some other screw, it may get screwed in so far it touches the motor brush holder, which will make the horn blow.

Smell each winding to see if it's actually burnt. I've seen dark and light enamel used on copper wire, and one coil may have been replaced. I put a light coat of grease on the wavy wheel.

A good working horn should draw about 5 amps.

Thanks Tom, I can't really smell whether it's burnt or not. Also, what type grease did you use on the wheel? And are you talking about this being the wavy wheel?

[sconnors]

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Originally Posted by 700rpm

If it's original, I'd clean the rust off the diaphragm and apply a thin coating of light oil to stop further deterioration. I haven't found a repro diaphragm that worked properly.

What's the best type of oil to use? And is this the diaphragm?

[harleytoprock]

My windings also looked like yours. On the diaphram, I just worked in some grease on to the surface to prevent rust. Just enough to make the surface wet. If the horn is stuck on , you have something going on in the switch housing.

[sconnors]

Originally Posted by harleytoprock

My windings also looked like yours. On the diaphram, I just worked in some grease on to the surface to prevent rust. Just enough to make the surface wet. If the horn is stuck on , you have something going on in the switch housing.

Thanks, what kind of grease did you use?

[1930artdeco]

Yes on both questions Sconners. That is the wavy wheel and the diaphragm. Any light coating of oil will stop further corrosion.

Mike

[harleytoprock]

I used nothing special chassis grease on the diaphram. For the armature, I use a electic motor oil that I got from Ace hardware. That oil works also good on my attic fans!

[harleytoprock]

Also, get a pair of new gaskets from Snyder's. I had to trim a little on the outside diameter of the gaskets to fit better. It also can't hurt to grease the gasket mounting surfaces.

[sconnors]

Originally Posted by harleytoprock

Also, get a pair of new gaskets from Snyder's. I had to trim a little on the outside diameter of the gaskets to fit better. It also can't hurt to grease the gasket mounting surfaces.

I did order some new gaskets along with the bolt set as I only had two holding it together!

[700rpm]

Originally Posted by sconnors

What's the best type of oil to use? And is this the diaphragm?

That is the diaphragm. I use 3-in-1 oil, rub a good coating on, then wipe it off with a soft cloth so only a very light coating remains. I put just small dab of chassis grease on the ratchet. Be sure to also oil your felt on the motor armature, just a drop or two every 500 miles or so.

[Tom Wesenberg]

Originally Posted by sconnors

Thanks Tom, I can't really smell whether it's burnt or not. Also, what type grease did you use on the wheel? And are you talking about this being the wavy wheel?

Yes, that's the wavy wheel or ratchet wheel. It barely touches the diaphram stud to make the correct sound. I use Mystik JT-6 High Temp grease for just about everything I grease. I also smear a thin coat of grease on the diaphram to prevent rust. Notice that the diaphram has to be in the correct orientation for the ratchet wheel to strike the chisel point just right. You want the line on the wheel to be in line with the sharp edge of the chisel point of the diaphram. I also use a dab of grease at the armature shaft to spring by the wavy wheel.

Do not sandblast the rust off the diaphram. The first horn I worked on years ago I did, and it ruined the diaphram.

[stewwolfe]

Don't try to paint the diaphragm either. I did that once and it ended up sounding like a bull being castrated.

[Alan Greenleaf]

The terminal ends on the terminal block appear to be touching each other, also there is only the lower block so the ends appear to be loose and aren't secured in the block as they were from the factory. This must be separate or the horn is shorted and will not operate.

[mot]

another spot that may give you trouble is the insulating washer that holds the brush holder to the frame
on the stewart warners like yours its a phenolic washer
spartons have a thin insulating washer
sometimes they are broken by over tightening
or even left out on a rebuild
of course this shorts the brush to ground
and also on your horn the nut holding the wavey washer is a left hand thread
tom

[sconnors]

Originally Posted by Alan Greenleaf

The terminal ends on the terminal block appear to be touching each other, also there is only the lower block so the ends appear to be loose and aren't secured in the block as they were from the factory. This must be separate or the horn is shorted and will not operate.

Thanks, when you say there appears to only a lower block I'm not sure what you mean? And the two copper contacts should NOT be touching each other?

[Bob C]

After the hint from "Eagle Eye Alan" you need the horn
terminal insulating block assembly, see the link.
http://www.brattons.com/product.asp?...=any&PT_ID=all

Bob

[sconnors]

Originally Posted by Bob C

After the hint from "Eagle Eye Alan" you need the horn
terminal insulating block assembly, see the link.
http://www.brattons.com/product.asp?...=any&PT_ID=all

Bob

Bob,
Not sure where this goes on mine. Can you clarify or point to it in one of the pictures I attached?