I finally got around to replacing my instrument bulbs with LED bulbs and the lighting still sucks. The factory placement of the bulbs makes no sense...the bulbs are way off to the side of the indicator gauge. Will a new set of "Sylvania 158's" light up better or is it just the poor bulb placement by the factory?
Instrument bulb lighting...still dim
- Thread starter ZooKypr
- Start date
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There are several things that contribute to dim instrument bulbs. Most common first efforts are headlight swich and bulbs. Not all panels are the same so I'll guess your isa metal insrument housing with lamp sockets attached to a circuit board. Lamps position has a screw attaches the circuit board. These screws are also one of serveral pieces of the ground path. Its more like a chain than a wire. For this clean to conduct current like a wire, every link must be well connected.
The very best solution is to install an actual ground wire.
The very best solution is to install an actual ground wire.
dustoff440
Well-Known Member
check any grounds
Do you have a big woven ground strap somewhere? If not, get one.
67Dart273
Well-Known Member
Turn on the dash lamps and twist the dimmer all the way to the left, but just before it clicks on the dome switch. Then get your meter, get "down" to the fuse panel and find the inst fuse, all the way to one end of the panel. It's the smallest fuse. Check voltage to ground at both ends of the fuse.
My headlight dimmer knob only illuminates my dash lights in a certain position. If I rotate it either way just a 'hair' the instrument lights go out. Its always been like that since I got my '66 Barracuda over 10yrs ago. Also, awhile back I replaced my floor mounted high beam switch and after the install the high beam indicator 'red' light illuminates when its tghe low beam is on and goes off when the high beams are on. This didn't happen with my old switch. Could this interefere with the circuit?
d55dave
Well-Known Member
Your headlight switch is NFG, the dimmer rheostat is broken and only providing partial voltage to the dash lights. Buy a new switch and be done with your problems. Most auto parts stores carry them.
You really dont need to replace the switch for a failed dimmer reostat.
It is quite simple to install a jumper over that reostat which results in bright as possible dash illumination regardless where the knob is turned to.
It is quite simple to install a jumper over that reostat which results in bright as possible dash illumination regardless where the knob is turned to.
68 CUDA FORMULA S
Well-Known Member
I had the same problem with my 66, I bought a new switch from Oreilly's and replaced the bulbs with some of Slant six Dans 2886X's and now my gauges light up real nice and bright.
Bob
Bob
That bulb is correct for pre 67 bulb sockets. Sylvania 2825 would be the optional bulb for 67 and later.
67Dart273
Well-Known Member
Houston, we have found the problem!!!
IMPOSSIBLE. You changed something else besides the switch. You changed the wiring somewhere. Did you change headlight wiring, change the sockets?
OR your cluster is not grounded
Thanks for everyones insight...I will get a new dimmer switch.
Originally Posted by ZooKypr
Also, awhile back I replaced my floor mounted high beam switch and after the install the high beam indicator 'red' light illuminates when its tghe low beam is on and goes off when the high beams are on. This didn't happen with my old switch.
But in regards to the high beam switch:
"IMPOSSIBLE. You changed something else besides the switch. You changed the wiring somewhere. Did you change headlight wiring, change the sockets?
OR your cluster is not grounded"
The switch is just a plug in repair thats all I did. Never touched anything else. Maybe my size 13EEE hit a wire when shifting over the years! I'll have to due some further investigation and get back to you guys.
Originally Posted by ZooKypr
Also, awhile back I replaced my floor mounted high beam switch and after the install the high beam indicator 'red' light illuminates when its tghe low beam is on and goes off when the high beams are on. This didn't happen with my old switch.
But in regards to the high beam switch:
"IMPOSSIBLE. You changed something else besides the switch. You changed the wiring somewhere. Did you change headlight wiring, change the sockets?
OR your cluster is not grounded"
The switch is just a plug in repair thats all I did. Never touched anything else. Maybe my size 13EEE hit a wire when shifting over the years! I'll have to due some further investigation and get back to you guys.
ESP47
Well-Known Member
Do you know where the factory location of this goes to?
hemitheus
19? Plymouth Scampenstein
another piece of advice is to lose the blue plastic color diffusers. It adds color to the light but is does also diminish the brightness
Diffusers are there for 2 reasons.
1. They catch the bulb if it should fall from the socket ( any color would have served that purpose ).
2. Incondesent light is a harsh yellow tint ( like a candle/fire ). The blue tint changes that yellow to a coke bottle like green tint. Less tiring on the eyes.
1. They catch the bulb if it should fall from the socket ( any color would have served that purpose ).
2. Incondesent light is a harsh yellow tint ( like a candle/fire ). The blue tint changes that yellow to a coke bottle like green tint. Less tiring on the eyes.
One side mounts to the motor (front or back) and the other end attaches to the frame. Wish I could be more specific on the location -- far as I know there was no set spot for it -- but this is similar to what you're looking for:
View attachment ground strap.jpg
Headlight dimmer switch is replaced and it works as it should but my instrument bulbs are still dim. My guess its because I used LEDs and not the factory 158 clear. I'm going to order a set of 6 and go from there.
As far as the high beam switch I will work on that issue later, gotta eat dinner now...pork roll, fried onions & cheese omlette, french fries & toast!
As far as the high beam switch I will work on that issue later, gotta eat dinner now...pork roll, fried onions & cheese omlette, french fries & toast!
JTG
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Been down this road, changed the headlight switch for factory new, replaced bulbs for brighter ones, and also added a ground, didn't make much difference, which makes me think that these cars probably never had bright dash lights from day one, not like todays cars.
d55dave
Well-Known Member
The fact that your dash light dimmer switch (for the instrument lights, when you rotate the headlight switch) is intermittent, and only works kind of in one position is a dead givaway that YOU NEED A NEW HEADLIGHT SWITCH. They are reasonably cheap at auto parts stores, and can be installed in less than 30 minutes. There is a round spiral of wire that runs on a wiper contact, and rotates with the knob. It gets old and broken, only working in one spot. It is essentially a variable resistor that varies the voltage to the dash lights. Put a new switch in the car and solve your dim dash light problems.
Which setting on my tester do I set it to? When it comes to electrical troubleshooting I'm lost. I can test a battery or alternator for voltage but that's about it!....lol
67Dart273
Well-Known Member
I don't know what meter you have, or whether it is "auto" ranging
Set to read DC volts, and if manual, pick a scale above 12V, IE 20, if the next range down is 10, etc.
Make sure one meter lead is well grounded, and make sure the park/ dash lamps are on, with the dash dimmer to "full bright" (normally to left, CCW)
Measure first one, then the other end of the short little "inst" fuse which is at one end of the fuse panel.
Set to read DC volts, and if manual, pick a scale above 12V, IE 20, if the next range down is 10, etc.
Make sure one meter lead is well grounded, and make sure the park/ dash lamps are on, with the dash dimmer to "full bright" (normally to left, CCW)
Measure first one, then the other end of the short little "inst" fuse which is at one end of the fuse panel.
Sometimes a squirt of electrical contact cleaner, if you have some on hand, and rotating dimmer switch left & right a number of times will clean the corrosion off of that resistance coil controlling voltage to dash lighting… sometimes it won’t. Headlight switches are fairly cheap as stated above.
autoxcuda
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Good idea to go thorugh ALL the connections in your electrical system. Starting with the bulkhead. Get the right tools to remove the pins and sockets from the plastic bulkheads.
Mark all the positions and take reference pictures before taking anything apart.
Steel wool, sand, acid dip, brake clean, etc every connection. Make sure the female sockets grip the male terminal tight. Check for brittle wires.
Common brittle wire is the ones comming off the amp gauge. I've seen the wire inside fail, but they look fine outside.
The plug into the high beam switch gets fried commonly too. Check the inside condition of the plug for corrosion. And check the condition of the wires comming out of it.
Mark all the positions and take reference pictures before taking anything apart.
Steel wool, sand, acid dip, brake clean, etc every connection. Make sure the female sockets grip the male terminal tight. Check for brittle wires.
Common brittle wire is the ones comming off the amp gauge. I've seen the wire inside fail, but they look fine outside.
The plug into the high beam switch gets fried commonly too. Check the inside condition of the plug for corrosion. And check the condition of the wires comming out of it.
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