The Stovebolt Site Forums The Shop Area The Electrical Bay A dark night and Suddenly, I was blind!

I was taking a little trip over to my nephew’s house last night after supper. Getting dark around here about 6 in the evening now and it was about 8 before I left. I live kind of out in the country, if you can call it that any more, so there aren’t any streetlights on the two lane blacktop roads. We’re not so far out that there isn’t any traffic, just the opposite. All the pilgrims have been moving in and at 8 o’clock in the evening there’s a steady stream making their way home from jobs in the city.
So I get a bout 5miles from home rounding a bend at the top of a hill and running along at about 45mph in a 55mph zone where everyone pushes it to 80. When all of a sudden, all the lights on the truck go completely dead on me, I hadn’t touched anything, not the light switch nor dimmer. So there I was rolling along with, no headlight, no streetlights, the moon isn’t up yet, and it was as black as the proverbial well diggers you know what!
Luckily out of the corner of me eye; I’d caught a gravel drive off to the right just when I went blind, the only drive for a quarter mile. I hoped that I had judged the distance covered by my panic stop and made a hard right. I could see headlights a few hundred yards behind me back around the bend and at the bottom of the hill and I dint want someone ripping up on me at 80 with the truck stopped dark in the road. Thank the lord I felt the wheels sliding on the stones so I figured at least I’d caught some of the drive. There is deep ditch off to both sides of the road and drive so I got lucky.
Once I got my self calmed down I pushed the light switch in and pulled it out and every thing came back on. The guy’s house was a couple hundred feet off the road and he must have thought I was nuts flashing the headlights on and off over and over for the next 5minuets. I couldn’t get them to go dead again no matter how much I sat there pushing and twisting.
Need less to say the rest of the trip and the ride back were a little tense. And for the next six months I’ll probably avoid night driving like the plague.
Denny Graham
Sandwich, IL

Denny Graham,

Back on 8/01/07 you posted pictures and a piece about headlight switches. The pictures (quality ones too) show your switch scattered about the bench as you 'rebuilt' the rheostat and fiddled with it. Did this episode turn around and bite you in the arse at the most inopportune time?

Stuart

My dash lights will go out sometimes when I hit a bump. It's a problem with the switch. This wasn't too bothersome when I was at 6-volts but my lights are so nice and bright at 12-volts, it's really startling when the dash goes dark. My headlights aren't affected thank goodness.

First thing that crossed me mind also Stu. I must have run the whole sequance through a hundred times and there is no way that the fix could have affected the main head light contacts. If you takie-look-see, I didn't break down the main part of the switch, just the dimmer section. The main body is a little more dificult to disassemble and still reassemble. Maybe I should have taken it ALL apart and checked the head light contacts. If the dimmer conections were corroded then it's entirely probable that the main contacts have some corosion. They are sealed up a little better than the reostadt so I gambled on them being OK. Lights are all nice and bright so there didn't seem to be any voltage dropping across a bad contact.
It only opened on me that one time and I've been running round with the lights on even in the day time to try and duplicate it, but nota. Sure shakes your confidance.
I guess I'll have to carry a half dozen flashlights and roll of duct tape around in case it happens again some time.
Denny Graham
Sandwich, IL

p.s. Restored Dash Dimmer works perfect by the way!

Denny,
I had a similar series of episodes with my '42 Chevy pickup. Check to see if you have a circuit breaker on the back of your headlight switch. Mine had dirty contacts causing a poor connection, leading to heat which finally caused the breaker to trip. After setting awhile the lights would work (after the breaker cooled). I believe I got a new breaker from the local auto parts shop, replaced that without replacing the whole switch, and never had the problem again. It certainly is very scary going down a dark rural road and suddenly lose your vision!

Good idea Dad, is this the contact that you’re talking about?
http://rides.webshots.com/photo/2025395520098611668coAUHH
I’d forgotten all about that. I don’t see why that would have opened and then reset in less than a minute and then worked ok for the rest of the night.
I think I cleaned the contacts when I restored the rheostat but I’ll check it again. I’m just to sore tonight cuz I spent the whole day on the creeper for my 1000 mile check up, lube job and brake adjustment.
Denny Graham
Sandwich, IL

The switch on my 42 is aftermarket (previous owner converted the truck to 12v and moved the switch lower on the dash) so it looks different but I believe functions as yours does. Mine is bimetallic so if it heats up from too much current it swings away from the contact, causes a break in the circuit. I reasoned that a dirty contact caused it to get hot and subsequently kill the lights. The lights would come back on after 2-5 minutes and on I would go, until they would go out again after a variable amount of time, up to half an hour. In frustration, during one of the outages I stuck my hand up around the switch in an attempt to find a loose connection, and felt the heat. I am not sure by any means this is what your problem is but I thought I would bring it to your attention.

LET THERE BE LIGHT!
Well Dad, you get the gold star for the day. I took a spare switch down to the bench and heated the contact leaf up with the soldering Iron and bingo, opens right up. So now I'm sure that my trouble had something to do with that contact.
Just amazing what one can learn on the Stovebolt, ya just saved me a month of testing/tearing/reading and experimenting till I found the problem.
This did prompt me to open up the book and low and behold, on page 12-33 under Lighting System, the second paragraph describes the exact trouble. “42 ampere thermal circuit breaker”
TKS
Denny Graham
Sandwich, IL

Since i own several British cars.. and thus am a diciple....Shall I make an offering in your name to LUCAS.... the Prince of darkness..... that he may never grace your truck again?

Michael

42 amps....wow, those are some heavy duty headlights you got burning in Sandwich.

Stuart

I gave ya the exact page and paragraph that those values came out of Stu, but here it is again. “Chevrolet Truck Shop Manual” 1948-51, pg 12-33, “1948-49 has a 30amp breaker and 1950-51 has a 42amp breaker.”
Whatcha still usin’ gaslights on the flatbed????
Denny Graham
Sandwich, IL

I was not aware that headlights had circuit breakers or fuses. I just thought it was a safety measure to not have Denny's trouble while driving. While in college I had an old 63 Plymouth, former LA County sheriff's vehicle. The lights would not go off while driving but if I turned them off for a few minutes when I stopped, they would not come back on until they were ready to come on. That might take 30 minutes or more. Never figured out what caused it but it sure made parking with a date handy.

Well Big Jim, next time your out at night with that '51 just wrap your hand up round the top of that light switch. Make sure your ready to pull her back real quick though.
Denny G

I've had that happen a couple of times... i just mashed my dimmer switch and they came back on... but it was a BAD dimmer switch that caused my problem!! put in a new one and it didnt happen again.

That was the first thing I hit even before I stopped the truck in the gravel. That wouldn't have killed all of the lights anyway. It was the breaker points, I'm sure. I ran a jewlers file through them and hope that did the trick. By bending the tab that the bimetal strip is mounted to you can adjust the trip point. After 57 years ya just never know if some backyard wizzard tried to re-adjust it in the past.
Denny Graham
Sandwich, IL