Turn Signal Switch Greenhorn
 

After reading everything I could find here I'm pretty sure my lack of brake lights on my 67 GMC shortbed is being caused by a bad turn signal switch (turn signals/flashers/running lights all work fine).

One thing I did notice is I have a slight draw from the battery (it sparks a little when connected) when the turn signal switch is connected. After I unplugged the turn signal switch half-moon connector the current draw is gone.

I have pulled my steering wheel and now have some questions that I hope the group can help me with:

1.) Do you think my switch has ever been replaced before? The half moon plug connection says Delco Remy and has a 67 on it. Main reason I wondered is all the replacement switches that say "same as original" seem to have the red-colored "stalk" that you pull to turn your emergency flashers on. As you can see mine is not like that.

2.) Are there any pros/cons for going with a replacement switch that has the half-moon plug end already on it...as opposed to the ones with the long flat plug/adapter harness?

3.) Can either of these 2 types (half-moon or flat) be installed without pulling the connectors out of the plastic plug end?

4.) Recommendations (for either type) for a vendor to purchase from?

Thank you.

Re: Turn Signal Switch Greenhorn
 

Im currently replacing my steering column from manual to a automatic. Your switch looks like the automatic column switch I have with the straight plug, not sure what year it came from. The manual is out of a 69 and has the half moon connector. The "hazzard" switch is red one on the 69, the automatic I have has the black screw in like what you have.

Re: Turn Signal Switch Greenhorn
 

It's hard to tell from my pics but the hazard switch on mine is shiny chrome and says "FLASHER"...and it does screw in like your black one.

This 67 was originally a 3OTT, I swapped in a Saginaw 4-speed a while back.

Re: Turn Signal Switch Greenhorn
 

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I would say that is a replacement switch. My '68 has the red flasher knob. I can't say it has never been changed but everything is pretty original on it....

LockDoc

Re: Turn Signal Switch Greenhorn
 

I think you are correct LockDoc, I have never seen another one that looked exactly like mine (with chrome pull knob).

I haven't pulled it out completely out yet (waiting to have a replacement in-hand) but unless someone just reused the original pigtail/half-moon connector somehow, it's definitely a Delco-Remy with "67" on the connector.

Still trying to decide where to get the replacement. I think I would like to stay with the half-moon connector and not have to adapt to the flat connector but maybe that isn't that big of a deal.

Re: Turn Signal Switch Greenhorn
 

It isn't really a big deal but the flat one is kind of bulky looking. I know you can't see it from above but it just bothers me....

LockDoc

Re: Turn Signal Switch Greenhorn
 

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I don't know if they carry the half moon style switch but I have had good luck with either of these vendors. They are both in MO.

https://www.classicparts.com/1967-19...departments/7/

http://www.manestruckparts.com/

LockDoc

Re: Turn Signal Switch Greenhorn
 

Looks like Manes has the switch with the half-moon style, will call them tomorrow to verify...thanks for the info.

Re: Turn Signal Switch Greenhorn
 

Good deal. Let us know how it goes.

LockDoc

Re: Turn Signal Switch Greenhorn
 

Both of my ‘67’s have the chrome pull

Re: Turn Signal Switch Greenhorn
 

Interesting, thanks projectking. Maybe a 67-only thing?

Re: Turn Signal Switch Greenhorn
 

I believe it is.

Re: Turn Signal Switch Greenhorn
 

Just realized yours says flasher on the end and mine have it on the stem

Re: Turn Signal Switch Greenhorn
 

My 72 came with the red knob. Years ago it was replace with one with the chrome knob (delco replacement ) because the red knob had been discontinued. I believe they're remaking the red knob switches now.

Re: Turn Signal Switch Greenhorn
 

The turn signals get their power from a different source than the stop lights but the TS switch connects the stop light power to the yellow and dark green brake light/turn signal wires. It also cuts out brake light power to the TS light that is selected to flash or else the light would be on solid.

The brake light power wire is usually a white wire from the brake light switch to the column connector and runs up into the column to the TS switch. Check it for power at the connector with the brake pedal pushed. If there is power but the brake lights don't work then run a jumper from the white wire to the dark green wire or the yellow wire and push the pedal . If they work then the trouble is in the TS switch or the white wire is broken inside the column. It's also possible that the connector is bad or in rare cases the crimp in the wire is over the insulation and not contacting the copper wiring.

If you don't have power on the white wire at the connector then the brake light switch may be bad or the stop tail fuse is blown. Do tails work?

The brown wire in the middle of the connector is constant hot, key on or key off. Its for the hazards so you could use it's power to jump to the white wire and the brakes should light without pushing the brake pedal . If both lights work the TS switch is good.If you select a turn, then one of the brakes should go off and the TS is doing it's job.

Re: Turn Signal Switch Greenhorn
 

3.) Can either of these 2 types (half-moon or flat) be installed without pulling the connectors out of the plastic plug end?

Yes either style of switch can be installed without removing the wires from the connector. It is also not recommended to remove the wires because you may damage the tabs that hold the connectors in or the plastic connector, a loose wire in the connector can be hard to diagnose.

To replace you can follow the recent thread...just loosed the 3 screws holding the swith about 1.5 turns, then twist the metal upper collar, counter clockwise if I recall correctly about an inch or so and pull out while twisting.
Then remove the rubber and plastic bushings on the shift tube above the shifter bowl.
Remove the shifter arm
Pull the shifter bowl off the shift tube, now you have clearance for the wiring connector.
You will also have to fish the wiring through the column grommet, lube it a little with silicone or silicone grease and pull it up with a hook tool to fish the wiring connector through.

Re: Turn Signal Switch Greenhorn
 

I've never really paid attention to the different styles of these switches before but I will now, thanks.

Re: Turn Signal Switch Greenhorn
 

Everything at the back works (tails/hazards/running lights)...except for the brake lights.

Thanks for this explanation VetteVet, I will do some more testing and see what happens.

Re: Turn Signal Switch Greenhorn
 

Thanks for that randy500, I was sure hoping that I didn't have to pull that plug off of a brand new switch to install it. Hope to do some more testing and make a plan this weekend.

Re: Turn Signal Switch Greenhorn
 

Update: I did contact Manes Truck Parts and ordered a switch from them, they did have the half-moon plug in style like original. Ron was good to talk to and very knowledgeable, thanks LockDoc for letting me know about them. And thanks to djeCST also for this thread:

http://67-72chevytrucks.com/vboard/s...d.php?t=711090

It was very helpful. I didn't have to pull the plug to install though.

The install was pretty straightforward but I did have an issue that I will describe and maybe it will help someone else down the line.

After my first attempt to install the switch I connected my battery terminal and the horn honked. I was pretty sure that I had connected everything properly and didn't pinch or cut anything but I took it all apart again to try and figure it out. Reassembled and the same thing happened.

I took it back apart and with the battery connected this time I started reconnecting. First I plugged the half-moon connector...no problem. Then as I was sliding the turn signal switch/housing assembly onto the column the horn honked again.

I pulled the switch/housing back off and slowly slid it on the column again, this time I saw an arc from the inside opening of the switch to the column.

After looking at it I noticed on the back of the turn signal switch there is a small metal "cover" that was installed slightly crooked and was sticking out into the center hole just enough to touch the column, and make the horn honk. I tried to move it but having no luck with that I just took a small file and removed enough material to where it won't touch anymore.

I have attached pics of before I filed it, the problem area is the small gray metal piece that is at about 9 o'clock on the back of the switch and you can see how it was sticking out too much. On the original switch that piece of metal is quite a bit narrower.

Once I got past that issue I put everything back together and my brake lights are back.

Thank you to all for helping me out on this, much appreciated. :cool:

Re: Turn Signal Switch Greenhorn
 

Good deal, glad you got it all sorted out. I used to stop at Manes every time I went to Texas to visit my daughter, and yes they are great people. I have since found a local guy that sells '67-'72 parts so I haven't stopped for a while.

LockDoc