Dash lights

[Mark873]

Been working on gage lights, gage lights didn't come on when pulling out switch, think I have that fixed, bad printed board, on order QUESTION, installed LED bulbs when I turn on the key the gage lights come on, go out after start, is this the way 73's work? would be a nice option see your gas gage. ?????

 

[midlife]

Alternator indicator lamp, oil pressure gauge lamp and brake proportioning lamp glow when the key is in CRANK position and then go out when key is returned to RUN. It is required that incandescent lamps be used in alt indicator lamp socket, as the bulb is part of the circuit and putting an LED in its place means no charging of the battery.

 

[Mark873]

Thanks for the reply, also the brake light must be incandescent.

 

[Stanglover]

Thanks for the reply, also the brake light must be incandescent.

I've not heard about the brake (idiot) light, but yes, the ALT must remain incandescent.

 

[RJM72]

Is that true only for the ALT idiot light? Or does that also apply to the factory alternator gauge?

 

[midlife]

Only the alternator indicator lamp, which is a completely different circuit than the ammeter gauge.

 

[RJM72]

Thanks. Kinda thought so, but better to check before rather than after everything is back together again.

 

[mrgmhale]

Only the alternator indicator lamp, which is a completely different circuit than the ammeter gauge.

Midlife, interesting re: LED for alternator idiot light causing disruptions. I "think" that is what you are saying. I am going to be adding annotation to that effect in my schematics files.

 

[mrgmhale]

Perhaps I am misreading or over-thinking the original post. Despite that possibility I thought it would be worth mentioning that for incandescent dash illumination bulbs being replaced with LED lighting, the LED lights are polarity sensitive. If they are not coming on when the headlight switch is turned on it is possible the LED lights that not coming on need to be removed from the circuit board and rotated 180 degrees to get the proper polarity.

Also, I am pretty sure I have read that LED lights can't be dimmed using the conventional headlight dimmer rheostat. At that, not all LEDs can be dimmed even with the correct non-Rheostat based techniques as they have certain voltage threshholds needed to get them to illuminate. I need to dig into this a bit more to see if there is a way to dim LED lights, specifically for instrument panel illumination. In the event LED lights are not coming on I would be making sure the Rheostat is not in a dimming position rotationally, as the LED lights may be Go-No Go in behavior when inadequate voltage is applied to them.

I think it is about time I consider replacing some 194 incandescent bulbs with LED lights just to see how they behave with a headlight dimming rheostat, and if indeed the Rheostat does not work see what can be used to reduce LED light output levels. On the other hand I bet I can dig out info by doing a deep Google dive into the subject.

One thing I have read about LED lights in general is how many of the ones with brighter light output can and will overheat unless they they are equipped with a heat sink technology. I find it hard to believe an LED replacement for 194 bulbs would run hot enough to require an integrated heatsink. So, yeah, time to begin playing with this stuff. Perhaps this can become a Winter project using a 12 volt power source in the house with a mocked up instrument panel, conventional Ford light switch, etc. I have not bothered digging into this subject deeply as I replaced our idiot light instrument panels with Dakota VHX instrument panels. I am pretty sure I still have the original panels laying around in the garage - I sure hope so. That would be a fun interest area to dive into inside the house this Winter.

 

[Stanglover]

Perhaps I am misreading or over-thinking the original post. Despite that possibility I thought it would be worth mentioning that for incandescent dash illumination bulbs being replaced with LED lighting, the LED lights are polarity sensitive. If they are not coming on when the headlight switch is turned on it is possible the LED lights that not coming on need to be removed from the circuit board and rotated 180 degrees to get the proper polarity.

Also, I am pretty sure I have read that LED lights can't be dimmed using the conventional headlight dimmer rheostat. At that, not all LEDs can be dimmed even with the correct non-Rheostat based techniques as they have certain voltage threshholds needed to get them to illuminate. I need to dig into this a bit more to see if there is a way to dim LED lights, specifically for instrument panel illumination. In the event LED lights are not coming on I would be making sure the Rheostat is not in a dimming position rotationally, as the LED lights may be Go-No Go in behavior when inadequate voltage is applied to them.

I think it is about time I consider replacing some 194 incandescent bulbs with LED lights just to see how they behave with a headlight dimming rheostat, and if indeed the Rheostat does not work see what can be used to reduce LED light output levels. On the other hand I bet I can dig out info by doing a deep Google dive into the subject.

One thing I have read about LED lights in general is how many of the ones with brighter light output can and will overheat unless they they are equipped with a heat sink technology. I find it hard to believe an LED replacement for 194 bulbs would run hot enough to require an integrated heatsink. So, yeah, time to begin playing with this stuff. Perhaps this can become a Winter project using a 12 volt power source in the house with a mocked up instrument panel, conventional Ford light switch, etc. I have not bothered digging into this subject deeply as I replaced our idiot light instrument panels with Dakota VHX instrument panels. I am pretty sure I still have the original panels laying around in the garage - I sure hope so. That would be a fun interest area to dive into inside the house this Winter.

The simple answer to the question is to buy really good LED's in the first place for the dash.
I buy all my LED supplies (with the exception of the headlights bulbs) from Bill at HiPoParts Garage, www.HiPoParts.com
I bought two sets in the past and the Elite Series II is by far the better set. And yes, they are dimmable from bright to off with a standard headlight switch.
In my case, I also installed an LED headlight conversion using the Hella H4 headlight set that is supplied with Halogen bulbs, but I replaced those with Sealight 9003 LEDs. To this setup, I found water can get in to the headlight globes on our Mustangs and my solution was to design and construct ABS shields that eliminate any water issue. This is not the fault of the headlights, but the way our cars are designed whereby the headlights are fully exposed to water running between the hood and fenders. I also run the headlights through 2 relays and that makes a big difference to the dash light brightness.

 

[70cobrascj]

My cheap ones I bought off eBay dim with my original headlight switch.
I’ll probably replace them with the original color ones from Hi-po parts as I don’t really care for the blue I have now.
I also need to do my center gauges ones and I’m bummed I didn’t because I can see them in the dark.