Sold on LEDs

[Captain Obvious]

And as for putting a kit together... You know you won't get good brightness control unless you upgrade to a pulse width dimmer too, right?

If you use the LED's with the original rheostat, you'll be pretty much full bright all the time.

[TomoHawk]

That's correct.  Parts labeled 5050 and so on  give you the size of the LED chip, and other labels like T11 give the bulb style, but there isn't  much or any documentation.  They vary from bayonet to screw-base to tube/festoon, flat panel, etc.

It would be nice to know what they call the 'paddlewheel' bulbs we are discussing.

 

BTW- if you're going to 'over-drive' your LEDs by changing the resistor, keep in mind that you are also decreasing its lifespan, so you may want to make some spares and have spare bulbs on-hand, even though you will not need them for a while.

Edited April 4, 2016 by TomoHawk

[dmorales-bello]

5 hours ago, Captain Obvious said:

And as for putting a kit together... You know you won't get good brightness control unless you upgrade to a pulse width dimmer too, right?

If you use the LED's with the original rheostat, you'll be pretty much full bright all the time.

I kept several OEM incandescent bulbs in the dash (high beam indicators, turn signals indicators, brake ,AC/heater panel, etc.) and that allows me to have some control of the LED instrument illumination with the stock knob. The exact degree of illumination control is difficult to quantify but when going from full brightness, if I turn the knob all the way counterclockwise (minimal intensity) I roughly decrease intensity by about 50%. They never go off completely but by no means do they stay at full brightness. Since doing the dimmer control conversion isn't that easy a job (pulling the stock one, sourcing the new one, modifying the stock one and reassembly into the dash)  maybe some people might consider leaving a few of the original bulbs in the places mentioned where LEDs won't make any difference and still preserve about 50% of the stock dimmer function and save a bit of time and trouble. Just saying........

Now, if Captain Obvious sells the modded dimmers you can put me on the buyers list for sure! 

Edited April 5, 2016 by dmoralesbello

[TomoHawk]

The indicator bulbs don't go through the rheostat.  They are only part of the turn signal or headlamp circuits, which aren't dimmable.  If they seem less bright it's because they are very small bulbs, as they should be.  Only the gauge and heater panel bulbs can be adjusted ( and maybe the glovebox lamp?)

Edited April 5, 2016 by TomoHawk

[dmorales-bello]

1 hour ago, TomoHawk said:

The indicator bulbs don't go through the rheostat.  They are only part of the turn signal or headlamp circuits, which aren't dimmable.  Only the gauge and heater panel bulbs can be adjusted ( and maybe the glovebox lamp?)

OK, so I guess it's only the AC/heater control panel bulb that's involved in preserving partial dimmer function. The glovebox light is not dimmable. 

Edited April 5, 2016 by dmoralesbello

[TomoHawk]

That's how I have my car set up right now, using the rheostat.  I get the light to adjust from about 85% - 100% brightness, but I would leave it at full brightness, because the design of the gauges just doesn't allow enough light to reach the gauge face.

On my '78, the ashtray lamp and A/T selector indicator lamp are also dimmable.  I can't find the glovebox lamp on my wiring diagram. I think the connectors to the ashtray lamp (in the armrest) and the trans indicator lamp are still behind the radio somewhere and you could install an incandescent  bulb to use for something (like footwell lighting) to add to the rheostat capability.

Edited April 5, 2016 by TomoHawk

[TomoHawk]

As an aside,  I'm not going to modify my PWM unit to fit into the same spot as the rheostat, as Capn O did with his.  Instead, I will cut the connector from the rheostat and attach it to the PWM, and glue the PWM to a small bracket that attaches to the rheostat screws, with the knob down, like the 240Z has.  I won't have the knob visible, but you don't need to adjust it more than once a year, if at all, so hiding from view won't be a problem.

Edited April 5, 2016 by TomoHawk

[TomoHawk]

I was corresponding with the vendor of this 24 emitter LED bulb.  The auction is for 2 bulbs with $2 shipping, and so I placed an order for 8 pair, and I got $2 shipping for the whole lot.

 I prefer these to the tower bulbs, because the top of the tower bulbs aren't even glued on!  The whole top section will twist easily, and you need to twist it to get it to lock into place.  The paddlewheel bulbs  are a bit more robust, but you can twist them apart too if you try.

 

BTW-  this is how I get my LEDs installed into the sockets:

I pull the GW wire away from the socket to retract the contact and  clamp the wire with some hemostats.  Then the bulb can be easily be removed and an LED bulb can be installed.

Edited April 5, 2016 by TomoHawk

[Captain Obvious]

I'm not sure about the very early cars, but in general, here is what is dimmable:

• Gauges (speedo, tach, temp/oil, volt/amp/fuel, clock)
• HVAC panel
• Radio faceplate
• Hazard switch green indicator
• And the gear shift position for the auto trans if so equipped.

All the other things including cigarette lighter, glove box, ash tray, map light, high beam and turn signals, etc are non-dimmable and run full brightness at all times.

 

If you leave at least one incandescent in the circuit, you'll get some dimming function even with the original rheostat, and the easiest one to forget about is the hazard switch.

[Captain Obvious]

14 hours ago, TomoHawk said:

if you're going to 'over-drive' your LEDs by changing the resistor, keep in mind that you are also decreasing its lifespan

I'm putting in more resistance in addition to what was originally in there, so I'm actually significantly under-driving  the LED's. Remember... I'm trying to decrease brightness. I'm thinking that I should never ever have to go back in there again. Not for about 50K hours anyway.

My soldering technique is better than the kid in China that put them together the first time and I used enough glue to assure they won't easily twist apart like they did originally. 

[TomoHawk]

While I'm restocking on bulbs, is there a need for BA7 bulbs?  I think there is just one someplace.

 

[Captain Obvious]

They changed the bulb style for the littlest bulb over the years, but  I don't think there are BA7's in your year.

They used a smaller (smaller than BA9S anyway) bulb in things like the hazard switch, fasten seat belt warning, and defroster switch. But in 77 they used a T-1-3/4 globe glass wedge base, not a bayonet base. I didn't look into the earlier bulb style in earnest, but in 74 they used a different base for those small bulbs. So the earlier cars may use a BA7S, but the later cars don't. I don't know when the transition to the wedge base occurred, but you're after it.

For posterity, my 77 original bulbs for smaller indicators like fasten seat belt, hazard, defroster was a TSD 74 - Glass Wedge Base, T-1-3/4 globe - 14.0 Volt 0.10 Amp 1.4 Watt