57 lighting problem

[Dan H.]

Hi All, my friend Bill Carlo was out in his 57 250HP FI Corvette the other night. While driving home from a dinner outing he hit the high beam switch, all the lights went out. He punched the dimmer switch several times but no luck. He then pushed the headlight switch in and out and lights came back on. Fun on a freeway at night? Any ideas what to check/clean to ensure lights are reliable. This is an original 52K car, sold by Chip Miller many years ago. Thanks,
Dan

[Richard M.]

Re: 57 lighting problem

Simply a bad connection due to corrosion in the Dimmer or HL switch or wiring, or a overload with high beams on and the internal circuit breaker opened in the HL switch. Any of these symptoms can be casued by corrosion on the contacts.

Time to remove the switch, open it up and clean the contacts. Do the same with the dimmer switch, and get into the headlight harness wiring and take everything apart, clean all of the contacts, etc, etc.

If the wiring is 47 years old, anything goes. If not, unless you duplicate the problem and do a major diagnosis to find the culprit, it'll happen again at the wrong time. Best to find out what's wrong in daylight in the driveway vs night time in the country.

Rich
ps Why do windshield wipers only fail in the rain?

[Edward J.]

Re: 57 lighting problem

I Like the wiggle test with harness connectors while the lights are on, this will also sometimes make a easy dia. test for the intermittent problems. This along with Richs response should help your friend find the problem. The red battery feed wire at the H/L switch will sometimes heat up and create a open.

[Dan H.]

Re: 57 lighting problem

Thanks guys,it's a nice car, will be first time most of this has been checked. Original engine, 3 speed etc.
Dan

[John H.]

Re: 57 lighting problem

Hi All, my friend Bill Carlo was out in his 57 250HP FI Corvette the other night. While driving home from a dinner outing he hit the high beam switch, all the lights went out. He punched the dimmer switch several times but no luck. He then pushed the headlight switch in and out and lights came back on. Fun on a freeway at night? Any ideas what to check/clean to ensure lights are reliable. This is an original 52K car, sold by Chip Miller many years ago. Thanks,
Dan

Dan -

As Rich noted, start cleaning contacts. Note the two long skinny arms with points on the end in the photo below of a '57 headlight switch - those arms are bi-metallic, and when current exceeds a certain level, they pull away from the fixed points and the lights go out; when they cool, the lights come back on again (that protects the switch, as the circuit isn't fused). On later switches, this thermal circuit breaker function is buried inside the switch. Anywhere contacts or points are dirty, resistance is increased, and current goes up; current goes up, and the lights go out.


HeadlightSw57.jpg

[Dan H.]

Re: 57 lighting problem

Thanks John, does the 57 switch have a 'button' you can push to remove the knob like later switches?

[Richard M.]

Re: 57 lighting problem

If John's still snoozin'......

Yes it does. This is from a '56 but similar button to release the knob.

Rich

[John H.]

Re: 57 lighting problem

Dan -

When you remove the switch from the car, don't lose the unique U-shaped stamped spacer that goes between the switch and the back side of the instrument panel to keep the switch straight - they're rare as chicken lips, and most people have never seen one.


HLspacer1.JPGHLspacer2.JPGHLspacer3.JPG

[Richard M.]

Re: 57 lighting problem

John, How did they ever get the switches mounted at St Louis with that spacer? It's nearly impossible to get your hand up in there to keep it in position and then get the escutcheon nut installed from the front.

I use a piece of double stick tape on the notched face so it sticks to the switch metal front face, then insert the switch in from the back. It keeps the spacer from falling.

Rich
p.s. isn't another rare piece those little triangular spacers that space the gauges out from the dash? I don't think they're reproduced.

[John H.]

Re: 57 lighting problem

John, How did they ever get the switches mounted at St Louis with that spacer? It's nearly impossible to get your hand up in there to keep it in position and then get the escutcheon nut installed from the front.

I use a piece of double stick tape on the notched face so it sticks to the switch metal front face, then insert the switch in from the back. It keeps the spacer from falling.

Rich
p.s. isn't another rare piece those little triangular spacers that space the gauges out from the dash? I don't think they're reproduced.

Rich -

The switch spacer was missing on both of my 57's, but in both cases I found it lying in the U-shaped lower instrument panel reinforcement directly below the switch; one showed witness marks of having been installed at one time, and the other one didn't. I used the tape trick too. I don't think the little hollow plastic triangular spacers are reproduced - I made some from a plastic extrusion I found at a plastics outfit in Pontiac, Michigan many years ago.

[Dan D.]

Re: 57 lighting problem

John, How did they ever get the switches mounted at St Louis with that spacer? It's nearly impossible to get your hand up in there to keep it in position and then get the escutcheon nut installed from the front.

I use a piece of double stick tape on the notched face so it sticks to the switch metal front face, then insert the switch in from the back. It keeps the spacer from falling.

Rich
p.s. isn't another rare piece those little triangular spacers that space the gauges out from the dash? I don't think they're reproduced.

I agree Rich. Not easy to hold that spacer in place. Usually takes some of Mike's beast. At least the triangle spacers stay on the stud pretty good. But I have plenty of small spacers I could use if I lost one.

-Dan-

[Dan H.]

Re: 57 lighting problem

Thanks, now I can go in well informed and go through a good trouble shooting adventure! Gee, what could possibly go wrong in 57 years? Let you know how it comes out, Thanks,
Dan

[Richard M.]

Re: 57 lighting problem

Thanks, now I can go in well informed and go through a good trouble shooting adventure! Gee, what could possibly go wrong in 57 years? Let you know how it comes out, Thanks,
Dan

Dan, one other thought, if you guys are going to be checking and cleaning connections.....

.....also check the Main Ground feed junction in the harness. It's a bugger to get at but it's possible a corroded ground could give some trouble in the future too. This Black ground wire is attached with a bolt into a hole in the metal reinforcement bracket and also holds the park brake bracket. There's also another ground on the Cowl Vent Bracket stud at the firewall.