Dome light issue

-
Check brakelight switch at the pedal with a light tester. If it works there but not at the plug at the front kick panel going to the rear body harness, you probably have a bad turn signal switch. Your brakelamps run thru the turn signal switch.
Don't have a testlight right now. Need to grab one. Tested the voltage at the brake light switch on the pedal. 11ish volts with pedal not depressed, 0V (or close to it) with pedal depressed. Ill grab a test light and pop off the kick panel.
 
Just checked this. No brake lights. Turn signals work at the rear and tail lights with the headlight swtich on.
Just went thru this today, no dome light, brake lights did not work.
Blown fuse, simple as that.
 
Just went thru this today, no dome light, brake lights did not work.
Blown fuse, simple as that.
Mine are all intact. Every fuse showed about .2Ohms. Gonna pop them out and reseat them just in case though as theres a bit of corrosion.
 
Mine are all intact. Every fuse showed about .2Ohms. Gonna pop them out and reseat them just in case though as theres a bit of corrosion.
I would try it, I normally just test fuses with an ohm meter, but this one was blown.
My running lights and turn signals did work.
Initially I was thinking the brake light switch was bad, just bought the car a week ago.
I am glad it was a simple as a fuse.
 
Mine are all intact. Every fuse showed about .2Ohms. Gonna pop them out and reseat them just in case though as theres a bit of corrosion.
Quick and easy method to test fuses:
Test light grounded on door switch nut or suitable ground.
Key on.
Touch probe on both sides of each barrel fuse, if it lights up bright, theyre good.
 
Quick and easy method to test fuses:
Test light grounded on door switch nut or suitable ground.
Key on.
Touch probe on both sides of each barrel fuse, if it lights up bright, theyre good.
Ok tested that and it only lights on one side of the fuse. All the other fuses was both sides. Bad fuse then?
 
Quick and easy method to test fuses:
Test light grounded on door switch nut or suitable ground.
Key on.
Touch probe on both sides of each barrel fuse, if it lights up bright, theyre good.
Ayyyyyyyyyyyy this did it. Swapped the fuse and everything is gravy. I've never really seen the use for a test light before now. Fuse looks good, ohms fine but the second I swapped it bam. Thank you!
 
Just to share, I went through this on my 69 last year.
Should start out with a good socket. If the dome assembly is out of the car, you can try cleaning with vinegar and baking soda solution. Either soak it or brush it with a tooth brush. Then rinse clean and dry it. It should eliminate that corrosion and the socket will be bright colored again.
Also the bottom of the socket should have a bit of spring to it, that helps w the bulb connection, if not, work it or replace the socket.
Get your new bulb, lightly coat it w dielectric grease, (Vaseline will do). If all is clean, it will twist in easily.
Stands to reason your dome light was working and just suddenly stopped, that was exactly what happened to mine.
Got some sand paper on a punch and cleaned it out pretty well in the car. Just reused the old bulb since it went in easier and after I fixed the main issue (fuse) it was fine. Thanks to everyone for the suggestions!
 
Ayyyyyyyyyyyy this did it. Swapped the fuse and everything is gravy. I've never really seen the use for a test light before now. Fuse looks good, ohms fine but the second I swapped it bam. Thank you!

That is a good lesson. LOADING a circuit often shows off problems that a voltmeter and especially ohmeter often does not

A couple of useful tools for this:

First of course a common probe mounted test lamp. I use both LED sometimes but more often a LAMP type test lamp, because it puts a little load on the circuit

Sometimes you want MORE load. For that, rustle up a useable stop/ turn lamp socket and an 1157 lamp. You can wire this several ways to provide more or less loading:

HIGH wattage lots of load.........connect to the shell of the test fixture and wire both wires together and use the two wires together as the second connection. You have two filaments in parallel

SLIGHTLY LESS load......use the shell and the stop filament

LESS YET Use the shell and the tail filament

Even more "less.' Dont connect the shell, but rather use the two pigtail wires for your two connections. This puts the two filaments in series for "less" wattage

A REALLY HEAVY load.......scare up an old headlamp with at least one good filament. That's about a 50W lamp

AN EXAMPLE of how useful these might be:

Let's say you have a parasitic drain..........the battery goes dead, and you can't figure what it is

Remove battery ground........Put a test lamp in series........if you put your headlight in there and it lights up pretty goo, you have a HEAVY drain, perhaps a shorted alternator

Try the heavy version of the 1157, and then step down to say series. If it lights pretty dim, you have a drain that is not near as big as a short

Let's say the test lamp (the store one) lights really bright........Once it has a load enough to really light up the test lamp, you need a bigger test lamp to get an idea of what you are dealing with

So you think "Why not just put my ammeter in there?" (Multimeter) You can damage it or blow an expensive meter fuse (Fluke) Because if the drain is more than the current rating of your meter (10A whatever) then the meter fuse, if there is one, is what will protect the meter from overload.
 
Contacts on that bulb are very worn. I dont know if that can create a short in the socket and blow the fuse but something caused the fuse to blow.
One good thing about it, when the dome light fails you have to be concerned because you may not have brake lamps. Hope the fault isn't in the turn signal switch. Good luck
 
Contacts on that bulb are very worn. I dont know if that can create a short in the socket and blow the fuse but something caused the fuse to blow.
One good thing about it, when the dome light fails you have to be concerned because you may not have brake lamps. Hope the fault isn't in the turn signal switch. Good luck
Its strange. It looks like it was modified to fit that way. Dunno if the dome socket is different than the bulb or just worn out or what. That bulb goes straight in, engages no problem and lights fine. The new bulb wouldn't fit without an unsafe amount of pressure to push into the socket. The power booster died and left the brake lights on long enough to kill the car at one point so I think that's what popped it. Also strange that the fuse wasn't really blown, just didn't work. Probably been driving around with it like that for a bit honestly.
 
Its strange. It looks like it was modified to fit that way. Dunno if the dome socket is different than the bulb or just worn out or what. That bulb goes straight in, engages no problem and lights fine. The new bulb wouldn't fit without an unsafe amount of pressure to push into the socket. The power booster died and left the brake lights on long enough to kill the car at one point so I think that's what popped it. Also strange that the fuse wasn't really blown, just didn't work. Probably been driving around with it like that for a bit honestly.
The glass fuses now fail in a couple ways, one way is the little filament blows and its clearly visible. The other failure is in the metal cap,where it cant be seen.
Cheap big box store fuses are notorious for this.
 
-
Back
Top