turn signal switch/arm question issue identified and solved

[str12-340]

The car is a 1970 Dart. Working on replacing the turn signal switch. The arm (what sticks out of the column) is held on the switch with a long finely threaded screw which goes through a metal bushing in the switch and threads into the end of the arm. On the end of the arm is a cast rib that should keep the arm in position on the switch. That rib is wider than the V shaped notch in the face of the bushing. That seems to be why the arm loosens up over time until it doesn't function. Has anyone else run into this? I suppose I could file out the V until the rib fits nicely in it. Just wondering if anybody ran into this before?

 

[CFD244]

I've read here on the forum with folks suggesting blue loctite on the threads. Not sure if this is correct......Just waiting for mine to loosen as I only read about this after the fact.

 

[Oldmanmopar]

Are both pieces factory parts or is the switch a replacement? Could there be a difference in early pre 1970 arms and you have the wrong arm? Just something you could check. I have a container of different year arms but I never looked at or compared the ends. I know there are different screws though. Some are hex and flat screw and some are just hex.

 

[str12-340]

The screw is original, I thought the arm was original, but that is why I'm asking for advice. The switch is definitely not original. I replaced all the wiring when the car was rebuilt 3 years ago. I did pull a switch from an old column that still had the chrysler tags on it and that bushing/insert had the same V groove that the repop did. I should post some pictures here.

 

[Riggins44]

The car is a 1970 Dart. Working on replacing the turn signal switch. The arm (what sticks out of the column) is held on the switch with a long finely threaded screw which goes through a metal bushing in the switch and threads into the end of the arm. On the end of the arm is a cast rib that should keep the arm in position on the switch. That rib is wider than the V shaped notch in the face of the bushing. That seems to be why the arm loosens up over time until it doesn't function. Has anyone else run into this? I suppose I could file out the V until the rib fits nicely in it. Just wondering if anybody ran into this before?

I too had the turn signal lever loosen up and flop around. I pulled the steering wheel and just retightened the screw that holds the lever in place and I haven't driven much since I did it so I don't know if it will loosen up again or not. The turn switch was replaced by the previous owner so that may be the problem too. If you figure out a permanent solution that works please post it so if I end up having to address the issue again I get the right solution. Thanks.

 

[str12-340]

If you figure out a permanent solution that works please post it

I sure will. I rebuilt the column about 3 years ago when I rebuilt the whole car. It worked fine and we took a long trip where we drove the car everyday for 4 or 5 hours for a month and a half. Three weeks into the trip it started to loosen, but I had all the right tools with me and pulled the wheel in a motel parking lot and found the screw loose, tightened it up. Worked fine for another year and a half and then started to loosen up. I limped along until the good weather ended and really took it apart looking for a permanent solution and that was when I found that the part of the design that kept the arm from working back and forth in the metal bushing in the switch was not fitting together properly. I will figure this out. I'm currently waiting on a new switch. I hate to have to that car inoperable, so it won't be too long.

 

[str12-340]

Success - I found the flaw in the repop turn signal switches and all the ones I have looked at have the same issue. Installed in new switch is a metal bushing. The screw that attaches the turn signal arm to the switch passes through this metal piece and screws into the arm.

There is a ridge in the end of the arm that is supposed to fit in a V cut in the bushing. After extracting a couple of these pieces from dead original switches it is clear that the V in the repops is more narrow than the one in the originals. Original is silver and the repop is black.

WE NEVER SEE THIS, because you install the switch in the column and then thread the arm in through the column housing, BEHIND the switch and screw it in place. You literally cannot see the fit of the two pieces when installing the switch. Without the ridge fitting in the V just the slightest lack of pressure in the screw over time lets the arm move in the switch until in doesn't actuate the signal, and the post on the steering wheel will hit the switch in the wrong place and break plastic pieces off the self-cancelling mechanism.

The solution is to either find the bushing in an original switch which would outlast the plastic switch and wiring and swap the one that comes in the repop, or remove the piece from the repop and file the V wider until it fits the arm snugly. Do not do this while it is in the switch because the metal filings can wreak havoc in the switch. It's pretty easy to get it out.

 

[4spdragtop]

Great info Mike, nice sleuthing!
If its not gonna be a sticky, just copy n paste into a "how to".

 

[str12-340]

where/how do you post a how to? powers that be tell me there are too many stickies in the electrical forum already

 

[4spdragtop]

Lol, yeah I read that. Lemme get a link

 

[4spdragtop]

Try here
Articles

where/how do you post a how to? powers that be tell me there are too many stickies in the electrical forum already