Observation: only two or three dash lights come on when switch pulled AND turned to just the right spot.

Assumption: the switch is bad and some of the dash bulbs are burned out.

possible fix: clean current switch or buy new switch and LED dash bulbs



switch question: 1. Is cleaning current switch worth the time and effort?
2. LMC switch p/n: 47-0641 is $17.95 while the Dennis carpenter switch p/n: D3AZ-11654-A is $29.95. Both are listed for my truck(79 F100) and the images appear to be of the same part(I know images are not always reliable.) I have had quality issues in the past with LMC, but is the Dennis Carpenter quality worth almost double the price?

Bulb question: if I use LED’s in the dash does any kind of resistor to be installed as well or is it just a bulb swap?

 

Try to clean original 1st, you're not out anything except some contact cleaner.

 

I don't remember how many lamps are in the housing for instrument lighting on my truck but it has been awhile since I've been in there due to swapping them over for LEDs. I've had zero problems since and the instruments are way easier to read at dusk and dawn.

Your assumption about the switch being bad is probably correct, the dimmer section consists of a spring like coil of resistance wire and a wiper with what may be a block of carbon on the end of it. As you turn towards brighter, you are decreasing the resistance until you hit the rivet the holds one end of the spring. That would be full brightness. The block can wear, the spring can fail in a number of ways, including simply falling out and the pivot point for the wiper can come loose to the point it won't carry current.

Superbright says I used these 194 LEDs, I honestly don't remember. It was either them or these 74 LED's. The parts picker says it's the 194. Either way, they worked out of the box, they do dim although not quite as smoothly as an incandescent and as noted above, made a massive improvement in visibility.

Michael

 

cleaning the switch won't make additional bulbs start working...so if the switch only works at specific spots on the rheostat, cleaning it will only make the same bulbs work along the full sweep of the rheostat...if some bulbs aren't lighting, then you have a bulb or circuit problem specific to those bulbs.

 

There are only 2 bulbs in the gauge cluster that would come on with the headlight switch, three if the high beams are on.

Then one bulb to illuminate the headlight & wiper switches, one for the heater control, one in the radio if it is an OEM radio.

I agree, try cleaning the switch, see what happens. If that doesn't work, replace it. Try your local auto parts store for a replacement, they may have one.

 

Adding LEDs to your gauge cluster does not require anything other than adding the bulbs. Now, if you decided to add LEDs to the rest of the truck, then new flasher relays are required for the turn signals and hazards. Look up D's Nuts on Facebook. He is who I went through and got everything for both the gauge cluster and all of my exterior lighting also. He has great customer service and is a small business owner. He also has an eBay store too. His name is Doug Beam.

 

You do know the headlight switch **** and shaft come out as an assembly. Push the yellow button (in the pic) up and down a few times, pull push on the **** and shaft, then hold button down and pull it out as one. It can be sticky if it has never been out. Once out the headlights wil be ON, so FYI disconnect the battery 1st. If it will just NOT come out, go ahead and pull like hell (not the preferred method) to get just the **** off the shaft. Proceed with the dash bezel removal to access headlight switch retaining nut.

Then X2 on sure clean it, worst that can happen is you have to end up replacing it anyway. I would not buy LMC either, so IMO yes the DC one is worth the $. LED's must be put in the the correct direction. Yes it matters, wrong way install they will not work.

 

The quick responses and wealth of knowledge is amazing, as usual from y’all. I took apart the switch and shinned up all the contacts with 600 grit sandpaper. Works like a charm now! I was using the wrong term earlier about the bulbs. I’m wanting to replace the six in the gauge cluster, they’re 194 bulbs. My oreillys had two white, one amber and one blue … and they’re $12 each! Being concerned blue will mess with my night vision, and green is the stock color, I’m ordering green ones off Amazon. Found a pack of 30 for $11!!!!! Does anybody have any pics of their dash/gauge cluster with LED bulbs? I’d like to see what different colors look like before I actually pull the trigger on the green ones.

 

Red is the easiest for improved or less affect on night vision (instrument lights/radio face plates in airplanes and old helicopters, and the old angle neck flash light for map reading) were red all the way back to WWII. Then NVG's came along and you see in a green hue. And then blue/green monochromatic newer NVG type 6's came out. Bla bla bla I digress.
Is night vision green or blue?

The first type of technology is active illumination technology that couples imaging intensification with a source of illumination in the near-infrared band. The second technology, image intensification, holds the answer as to why night vision is green.
Bla bla bla Is green used for night vision goggles?

The phosphors in night vision goggles are deliberately designed to make green pictures for a couple of simple yet effective reasons: The human eye is more sensitive to light wavelengths that hover around 555 nanometers, which just so happens to be dominated by the color green.

Red can be a eye strain, so dash light are normally green and only the high beam indicator is blue. EQUIPPED TO SURVIVE (tm) - Green or Red for Better Night Vision? You ever notice if you turn your dash light down way low, you can see easier outside the vehicle when driving at night?

https://www.hipoparts.com/1961-79-fo...nversion-kits/

 

$12 each for regular 194 bulbs? Ouch!

I too was amazed a few years ago what cleaning the wiper and coil on that switch did. I went from being unable to read much except see the needle to being able to read the odometer at night.

 

Before LED upgrade



after

 

foofees pics show the night and day difference I saw when I switched to leds.

Michael