Took my 68 for a run and noticed my brake lights weren't coming on when hitting the brake. My running lights/tail lights work fine , hazard lights flash, signals work, I was hoping for a blown fuse easy fix but no fuses appeared to be blown. crawled under the dash and manually moved the brake light activation switch lever still nothing. I'm figuring since everything else seems to be working that its a bad brake light switch. The switch is in an awful location. you have to be gumby to wiggle under the dash and the switch is hidden partially behind the steering column so I cant really get a good look at it to see how its attached. I just wiggled the wires and moved the lever to try to bring it back to life but no luck. If it is the switch I'm not sure where I would locate a replacement part or how to get at it to install a new one (shop manual doesn't address these type of repairs). Any advise on this?

 

Just helped someone with this exact thing. Removing the switch is a hell of a job. Depending on if you are early or late 68 dictates the switch type. The early ones have a round switch with a lever. The laters use a push button style switch.

I would suggest after you remove the switch you try opening it and cleaning the contacts. The early switch is $65 and this can save you money. That is what we did on the 68 this past weekend.

 

I believe there is a slotted screw in there that allows some adjustment. I am going through this right now with my 68. I simply don't fit under there. It's even hard to see with a long mirror. My wife may end up under there if I bribe her

Anyone have a picture of a 68 brake light switch? The AIM is useless as is the FSM.

 

There are at least two ways to eliminate the brake light switch without removing it. Either jumper the two wires together, or measure for 12v on both wires with brake pressed. (You'll only have voltage on the orange wire with brake not pressed). The white wire goes to the turn signal switch. Contacts inside the turn signal switch open and close to interrupt the brake light voltage and insert the flasher voltage instead. It's a very common issue to have the turn signal switch contact loose or corroded and have the brake lights not work and the turn signals still work. The fact that the turn signals work just tells you that you don't have a problem with anything after the turn signal switch (the wires, bulbs, sockets, and grounds have to be good or you wouldn't get turn signals, it's the same exact wires, etc)
First eliminate the brake light switch by measuring voltage on the two wires. If you have it there, check the plug at the steering column that goes up to the turn signal switch to make sure it's fully seated. If it is, and you had 12v on the brake light switch, you'll need to get to the turn signal switch to continue troubleshooting.
If you didn't have 12v on EITHER wire at the brake light switch, you need to go back toward the fuse box and see where you lost it. A volt meter ( or if you don't have one, a test light) will tell you exactly where the problem is. Don't remove the brake light switch until you test it, it's a waste of time and energy, and you'll have to reinstall it if it's not bad.

 

If I connect the two wires (orange and white)wont this tell me if I have power to the switch? I assume the brake lights will light if theres power?

 

Read my post again. Second sentence in particular. If you don't get lights with those jumped, you need to check the voltage at the fuse and at the switch. After that, the turn signal switch. Just follow the earlier post.

 

Check at the orange wire connection for power, if you don't have power there then I'd suggest testing the right hand terminal in the fuse panel with the fuse in, if you don't have power there then test the left side. If you have power there remove the fuse and clean the terminals. Just because a fuse looks good doesn't mean there isn't any corrosion on the terminals preventing voltage from passing.

FYI.. All our technical schematics, diagrams, pictures, and videos are now on our Corvette Tech and Repair Help Site at this link. http://repairs.willcoxcorvette.com/

Willcox

 

Thanks. Just wANTED TO MAKE SURE i UNDERSTOOD THE INSTRUCTIONS. i DID JUMP THE ORANGE TO WHITE WIRES AND THE lights came on so I guess its the switch. I am considering trying to hook up a newer switch rather than struggle getting the old one out and back in. I notice on the coupler of the white and orange wires that a black wire runs to each one of them from opposite ends of what looks like a round capacitor or resistor. I dont notice it on willcox schematic. Is that needed if I modify the switch set up to a newer version?

 

The purpose of that capacitor is to eliminate pop in the am radio when the brakes are applied or released. It's totally unnecessary unless you're trying to go stock. As far as the switch, make sure that the plunger is moving when the brake is applied. Push down the brake and manually operate the switch and see if your lights go off and on. It should be spring loaded to extend when you move the pedal. If you have good contact on the orange and white wires to the switch connector, it does sound like the switch is the problem if they come on like you say when you jump the switch.

 

Yes. One of the first things I did was to crawled under the dash and manually moved the switch lever.

 

I missed where you said you jumped the wires and it worked, my apologies.

I have the reproduction switch and the original... they are a pita to install but it would probably be just as hard to convert.

https://willcoxcorvette.com/catalogs...e+light+switch

If you convert you'll need a switch mounting bracket and installing that might be just as hard as installing the switch itself.

I also have a used brake light switch mounting bracket too...

Willcox

 

Here is the easier way to change that switch:

REMOVE DRIVER'S SEAT;

Change switch;

Replace driver's seat.

Unless you are a contortionist or have an intelligent 10 year old grandson/granddaughter, the above procedure is a MUCH easier way to change that switch. AND, you get to clean up all the cr@p that's under the seat, check out the seat belt retractor, PLUS be out in the garage with a couple of beers while you're working.

 

Well I took another look at the switch and I moved the lever back and forth quite a bit. After messing around with it for awhile I was able to get the brake lights to come on when the switch lever is close to the end of its range or in this case with the pedal depressed almost as far as it will travel. Is there a way to adjust the switch to come on sooner? I would assume I have to loosen the switches mounting bolt to adjust its position?

 

Remove the wires/connectors. Loosen the locknut and run as far as needed to get the switch position you need. Screw the switch in/out as you need to re-position it. Snug down the locknut and put wires back on.

That should to it.

P.S. You don't want to have the brake lights come on with initial brake pedal travel; you want them to come on at the beginning of some resistance to pedal movement. Otherwise, if you have your foot just touching the pedal, the brake lights come on and the car behind you will think you have already started to brake. You can feel the point where pedal resistance increases...even with the engine OFF. Set switch position to come on just before or at the onset of pedal resistance. To aid you, connect an ohmmeter across the switch terminals as you are adjusting. When the contacts 'close' (ohmmeter goes to zero), that is when the lights will come on.

 

The 68 switch is way different than what 1969 and new cars have.. it doesn't screw in for adjustment. It has slotted holes that you use to adjust in/out.

I've never taken one of them apart but I can only imagine it's a pretty simple inside and probably needs a good cleaning. If you look at it you'll see where the black portion is crimped to the metal can... if you un-crimp this the switch will come out and you could probably clean it with ease.

 

Was that switch in all '68 C3's, or just the 'early' 68's?

 

All of them Charlie..

68's are so odd and by comparison, they are way worse than the 63's or for that matter any other year with the one off items.

 

Interesting. I had a '68..but WAY back in 1973...and never had to dig into dash area (car was only 5 years old), so I wasn't aware of THAT difference. Thanks for the info, and we appreciate your vast knowledge on these issues, which you are so willing to share.

 

Having just seen one apart they are very simple inside. It is a spring loaded bar that moves with the lever to create a path to the two wires. Each wire has a contact fixed inside the black plastic.

 

It's simple to clean... then re-assemble. Seems a bit cheaper than NOS and the reproductions, while they work have been known to have issues.