62 BREAKLIGHTS

[Dave]

Brand new member 33334


Recently the brake lights on my 62 corvette stop working. I replaced the turn signal switch, the cancel switch and the pedal brake light switch. No luck!


The turn signals work great so that leads me to believe that the wires and rear lights are in working order. I have checked the connections and everything looks good.


Any ideas on what else could be my gremlin?


Thanks

[John H.]

Re: 62 Brake Lights

Dave -


First thing to check is the two wires connected to the brake light switch; one of them is supposed to be "hot" all the time (battery-fed circuit), and the other one feeds to the turn signal switch, which provides the feed to the bright filaments in your taillight bulbs - direct when the turn signal switch is centered, or through the flasher when the turn signals are activated. Two possibilities - 1) The hot feed to the brake light switch is dead, in which case you will have no brake lights OR turn signals; 2)If you have 12 volts at the brake light switch input side and at the output side with the pedal depressed, and have no brake lights or turn signals, you have a problem at the turn signal switch - if the switch is new, but still no lights, it probably isn't centered properly (especially if you have turn signals). It only feeds the brake lights if centered. You may have noticed all the spring wires that are guided under nail-headed studs that make up the cancelling mechanism - unless all these (sliding) points of contact are both clean and well-lubricated, chances are your switch is not centering properly by itself. You can usually confirm this by wiggling the turn signal lever while your foot is on the brake pedal - if you get intermittent brake lights while doing this, your problem is definitely in the centering (cancelling) mechanism. Pull the wheel again, disassemble the cancelling mechanism, clean and lubricate it, move the little pin on the turn signal switch to make sure it moves smoothly, and re-assemble everything again. At the rear, the ground is usually the culprit, but if you have taillights, license lights, and your gas gauge works, that's not the problem (all those circuits share a common ground). Hope this helps.


John - '57 270

[John H.]

Re: 62 Brake Lights - Oops! - Revised

Dave -


Correction to my original post - if the hot feed to your brake light switch is dead, you will have no brake lights, but you WILL have turn signals (they're fed through the turn signal switch from an ignition feed, not from the battery). Sorry - brain fart.


John

[Bill Clupper]

Re: 62 Brake Lights - Oops! - Revised

Don't forget to check the fuse and the fuse holding terminals. Often, cleaning the terminals is all that is necessary

[Jack H.]

Re: 62 BREAKLIGHTS

Don't have '62 AIM so I'm taking a shot in the dark. I know on '63 cars there were various changes in RFI (radio frequency interference) design dealing with series vs. parallel branch of capacitors used across switches (brake and turn signal flasher can) that ran high current, long broadcast antenna feeds (front/rear lamps) to prevent 'clicking' and 'doinking' noise from entering radio.


Depending on design (series vs. parallel), it's possible for the decoupling cap to be bad or marginal producing either no lamp action or constant lamp action. Since these caps went with the radio option, it's not always obvious from the basic wiring diagram that there's the potential for a component to short/open at one or both switching interfaces (brake switch and TS can).


Short of having a 'Digibridge' to check capacitor's intrinsic capacity silhouette and leaking profile to specs, the 'poor boy' method is to simply remove the RF cap and see if the problem goes away....