Is this the problem with my horn?
Thread Starter
Race Director
Joined: Jul 2004
Posts: 12,705
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From: Scottsdale Arizona
Is this the problem with my horn?
I spent much of the morning trying to diagnose the problem with my horn that hasn't worked since I've had the car. I got the papers and some remedial help from Jim Shea (thanks so much Jim!) and went through the paper step by step. Long story short, the horn itself works (sounds pathetic), the relay works and I have continuity from the third harmonica wire to the sprung, plunger connector. I replaced the plastic insulator while I was in there (old one looked ok) and the cancel cam (again, the old one looked ok). Still doesn't work. I did check that there is continuity across the rag joint and there is. What I did notice is on the turn signal switch itself. Note the part that would ride against the brass part of the cancel cam:
Here's the same part from a side view:
Last, here is a pic that I found from a post that Roger did which shows what I think the part should look like:
Note the arrows. Is this my problem? If so, does anyone have the GM part number for the turn signal switch on a 73 with T&T?
Thanks
Here's the same part from a side view:
Last, here is a pic that I found from a post that Roger did which shows what I think the part should look like:
Note the arrows. Is this my problem? If so, does anyone have the GM part number for the turn signal switch on a 73 with T&T?
Thanks
Last edited by CA-Legal-Vette; Oct 6, 2012 at 07:50 PM.
Drifting
Joined: May 2012
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From: Calgary Alberta
Former Vendor
Joined: Aug 2006
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
http://willcoxcorvette.com/product_i...oducts_id=1429 $67.99 and if you use the sale code you can save more.. 
Hang on.. Looking for a picture
Willcox
Hang on.. Looking for a picture
Willcox
Last edited by Willcox Corvette; Oct 6, 2012 at 10:30 PM.
Le Mans Master
Joined: Jul 2000
Posts: 6,001
Likes: 113
From: Saginaw Michigan
That appears to by your problem. The spring loaded plunger should contact the underside of the cancelling cam. The picture of your original switch shows the plunger to be cut off or for some reason it was destroyed. New switches for 1969 through 1976 Corvettes with T&T columns have been repo'd and are available through Willcox and many other Corvette suppliers.
Jim
Jim
Thread Starter
Race Director
Joined: Jul 2004
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From: Scottsdale Arizona
Thanks guys. No idea of how that part would get chewed off. I'm pretty sure that the cancel cam and insulator had been replaced so who knows what the looked like before.
Looks like I need to change the switch. Any trick to fishing the harmonica through the steering column?
Looks like I need to change the switch. Any trick to fishing the harmonica through the steering column?
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,852
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Thanks guys. No idea of how that part would get chewed off. I'm pretty sure that the cancel cam and insulator had been replaced so who knows what the looked like before.
Looks like I need to change the switch. Any trick to fishing the harmonica through the steering column?
Looks like I need to change the switch. Any trick to fishing the harmonica through the steering column?
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Thread Starter
Race Director
Joined: Jul 2004
Posts: 12,705
Likes: 329
From: Scottsdale Arizona
That's clever! I wasn't looking forward to trying to get that big hunk of plastic through there.
One thing that I noticed in your instruction illustrations is that the lock plate spring was sticking up from the switch. Mine didn't. I'm wondering if this is whythe plunger got chewed off in the first place. Once I take it apart again to replace the switch I'm going to have a close look at the spring. I may order one just in case.
One thing that I noticed in your instruction illustrations is that the lock plate spring was sticking up from the switch. Mine didn't. I'm wondering if this is whythe plunger got chewed off in the first place. Once I take it apart again to replace the switch I'm going to have a close look at the spring. I may order one just in case.
Last edited by CA-Legal-Vette; Oct 7, 2012 at 10:55 AM.
Thread Starter
Race Director
Joined: Jul 2004
Posts: 12,705
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From: Scottsdale Arizona
Figured that I'd give an update and ask for yet another suggestion. I followed the procedure for changing the switch on the Willcox site. There are two separate sets of wires that come off the back of the turn signal switch. I removed them all from the connector and taped them to the stubs from the old connector. One separate pair of wires went through the column without issue. The larger bundle jammed almost immediately and the wires pulled out of the tape bundle. I'm now at a bit of an impass on how to proceed.
Looking down into the column, I can see something that looks like a flat, "conduit" like guide. At least the two wires go through this and I presume the rest should too. I think it looks like the part in the top, left hand corner of this page onthe Doc Rebuild page:
http://www.docrebuild.com/dr-r-web/ST-COL4.PDF
I was considering trying to feed a fish tape through the conduit. I also thought about trying to feed the wires from the new switch through the conduit though I'm not sure where it comes out.
Any better ideas?
Looking down into the column, I can see something that looks like a flat, "conduit" like guide. At least the two wires go through this and I presume the rest should too. I think it looks like the part in the top, left hand corner of this page onthe Doc Rebuild page:
http://www.docrebuild.com/dr-r-web/ST-COL4.PDF
I was considering trying to feed a fish tape through the conduit. I also thought about trying to feed the wires from the new switch through the conduit though I'm not sure where it comes out.
Any better ideas?
Last edited by CA-Legal-Vette; Nov 18, 2012 at 11:14 PM.
Racer
Joined: Jun 2011
Posts: 300
Likes: 3
From: kempton park Gauteng
Hi ,If you didnt pull a drag wire through tied to the old turn signal switch wires when you pulled them out , you will have to get yourself a thin wire welding rod , bend a hook on the end and then push the non bent end through the column and the conduit you spoke about .
Once you have the drag wire through feed the individual wires of the turn signal switch through the hook you made on the wire welding rod and bend the wires back on themselves . Tape the folded back wires and your hook with insulation tape so it cant hook on the column or conduit . From the underside of the column gently pull on the drag wire while feeding the switch wires in from the top , try to keep them as flat as the are moulded so they go easily through the conduit at the bottom of the column . To make it easier to get through you can cover the wires in talc , just pull gently and feed at the same time and you will get them through .
John , ps looks like that spring loaded contact got very hot !!!
Figured that I'd give an update and ask for yet another suggestion. I followed the procedure for changing the switch on the Willcox site. There are two separate sets of wires that come off the back of the turn signal switch. I removed them all from the connector and taped them to the stubs from the old connector. One separate pair of wires went through the column without issue. The larger bundle jammed almost immediately and the wires pulled out of the tape bundle. I'm now at a bit of an impass on how to proceed.
Looking down into the column, I can see something that looks like a flat, "conduit" like guide. At least the two wires go through this and I presume the rest should too. I think it looks like the part in the top, left hand corner of this page onthe Doc Rebuild page:
http://www.docrebuild.com/dr-r-web/ST-COL4.PDF
I was considering trying to feed a fish tape through the conduit. I also thought about trying to feed the wires from the new switch through the conduit though I'm not sure where it comes out.
Any better ideas?
Looking down into the column, I can see something that looks like a flat, "conduit" like guide. At least the two wires go through this and I presume the rest should too. I think it looks like the part in the top, left hand corner of this page onthe Doc Rebuild page:
http://www.docrebuild.com/dr-r-web/ST-COL4.PDF
I was considering trying to feed a fish tape through the conduit. I also thought about trying to feed the wires from the new switch through the conduit though I'm not sure where it comes out.
Any better ideas?
Thread Starter
Race Director
Joined: Jul 2004
Posts: 12,705
Likes: 329
From: Scottsdale Arizona
Well guys, got it all buttoned up today and my horn works for the first time since I got the car. The horn itself sounds pathetic but that's the easier part to deal with.
It was a pain to fish though the wires. Ended up using a tool intended to remove clogs. It's 18 inches long and fairly flexible plastic. It has barbs in the side and worked like a charm.
In any case, thanks for the help and suggestions. Amazing how much effort went into fixing something as "simple" as a horn.
interesting idea. I had assumed that it was damaged mechanically but I suppose that it could have been heat generated by a short.
It was a pain to fish though the wires. Ended up using a tool intended to remove clogs. It's 18 inches long and fairly flexible plastic. It has barbs in the side and worked like a charm.
In any case, thanks for the help and suggestions. Amazing how much effort went into fixing something as "simple" as a horn.
interesting idea. I had assumed that it was damaged mechanically but I suppose that it could have been heat generated by a short.