Turn Signal Cancellation doesn't work with new switch

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ACME SS

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I know this has been addressed probably more than a few times but I'm wondering if my problem is the result of a poorly built aftermarket switch. So I understand how the tang on the heavy duty spring on the back side of the steering wheel can (inside the copper horn collector) is to be positioned at approximately 9:00 and that when you put your signal on, it deflects the trip tab without tripping it, however the tang is to catch the trip tab as you recenter the wheel after the turn, thus tripping the switch off.

I have taken extensive measurements of the steering shaft diameter, length, etc., etc., and determined that about .035" of the cancellation tang should be engaging the trip tab. (the outer portion of the trip tang measures to be .318" from the steering shaft as calculated and mathematically determined). I have taken a .318" stack of feeler gauge leafs and slid it around the steering shaft and its sharp square edge catches and trips the signal switch just fine.

The switch required a fair amount of force to cancel by hand using the lever and made quite a "snap". I figured I'd take a little bit of the bite out of it and shaved off just ever so much of the stationary "catch" that holds the signal on. Doing so requires now much less force to trip it and it sounds much softer and more modern. I thought that was the fix...but no! I'm thinking the plastic trip point on this switch is made slightly different than OEM and instead of tripping the switch, it is deflecting. I think I purchased it from classic industries and as you can see the trip portion is yellow. I should mention the switch appears to be a cheap version as it does not have a horn wheel but instead a brass plunger. Wondering if anyone has had this problem and what the fix was? I'm thinking of adding a bit of "meat" to the steel trip tang by adding some JB weld putty to make it a bit larger in diameter.

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I have the same issue with the OER switch I bought, their generally good parts but this seems to be an exception. When I reassemble my steering column I am going to check and see if my assumption is correct, comparing it to the old switch I took out it is definitely lighter duty than original. I have part number MD2139, will be curious if we both have the same part/issue
 
@slantsixdan is a real expert on whether a switch is a good one or cheap one. I tagged him so maybe he'll chime in.
 
I used a 1970-up switch from Classic once, customer bought it, and the front park lights came on with the brakes lights. Was miss-wired inside of the EM switch.
 
I've had nothing but good luck with the Shee-Mar units and have heard the same from others. Have heard a lot of bad about the Classic ones and the only one I've used was bad. They do look the same though.
Please let us know how it goes.
 
Cool, I ordered one from rockauto. Hopefully this will fix the problem. Thanks again

I had the same type of problems with an aftermarket switch, and had to heat the cancel tab a bit to position it where it needed to be to work right.
(**** construction.)
Apparently the ones tha come from Dan are factory correct and work perfectly.
 
I don't believe that Dan carries the 1970 and up style. Please correct me if I'm wrong.
From his website: For 1962-'63 and 1964-'69 A, B, & C-bodies (without tilt steering), plus some trucks and vans up through 1971. The OP can email him at the link to ask though.


 
I don't believe that Dan carries the 1970 and up style. Please correct me if I'm wrong.
I don't know if he does or not. All I said was he would know a good one by looking at it.
 
Looks like ACME already purchased the Shee-mar. I bought a Shee-mar for my '69 before I knew about Dan's switches *sigh*. It works okay but if it breaks I will contact Dan and I recommend his as well. They are the best quality of all the replacement switches.
 
That switch is junk. Had one, never really worked right. Plastic is thin and will crack and bow creating more issues.
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Ouch!
That is junk!
Warping might have something to do with not cancelling!?
Thinking a new one wouldn't be warped but its possible these days!
 
Ouch!
That is junk!
Warping might have something to do with not cancelling!?
Thinking a new one wouldn't be warped but its possible these days!
The warping is caused by thin plastic material and spring tension in the brass contacts. Wasn't warped when new. Became warped though some use, and cracked. It was the cause for the cancel feature to stop working due to mis alignment of the cam.
From Classic?
I don't recall but I have to believe all the yellow cammed switches are from the same manufacturer.
 
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