gauge backlighting

N8N wrote:
> On Mar 3, 8:36 am, "Pete C." > wrote:
>
>>Nate Nagel wrote:
>>
>>
>>>Pete C. wrote:
>>>
>>>>Nate Nagel wrote:
>>
>>>>>So I finally got the Ugly Truck reasonably in shape today... got a
>>>>>camper shell off Craigslist, so I had to run a wire to the back of the
>>>>>truck for the third brake light. I had some old gauges that I wanted to
>>>>>install, along with a new trans temp gauge (I quite possibly be doing
>>>>>some towing/somewhat heavy hauling with this truck) so I put those in as
>>>>>well since I was in the groove. Ended up running to the grocery store
>>>>>after I was all done...
>>
>>>>>I guess sometimes it is worth it to buy the expensive stuff. The oil
>>>>>pressure and vacuum gauges I used were parts store "Sunpro" gauges, and
>>>>>the trans. temp. gauge was VDO (only VDO apparently makes a trans. temp
>>>>>gauge with a chrome bezel and white lettering/pointers.) I even popped
>>>>>for the Auto Meter "bulb condoms" to make the backlighting match the
>>>>>dash. Well the VDO gauge was perfectly legible, the Sunpro gauges...
>>>>>not so much. I'd thought that I was having a hard time seeing them in
>>>>>my old Stude because of the generator, old wiring, whatever... nope, the
>>>>>backlighting in them just sucks, because the new VDO gauge right next to
>>>>>them in the gauge panel is perfectly readable. I'm going to see if I
>>>>>can find some 1816 bulbs (highest MSCD bulbs I could find in that
>>>>>format) to see if it helps, but I may just end up sucking it up and
>>>>>buying more VDO gauges. Grr.
>>
>>>>>nate
>>
>>>>Go LED. Much brighter, cooler and last about forever. I got tired of the
>>>>burned out button lighting on the radio in my truck and after tearing it
>>>>apart, I replaced the burned out incandescents with white LEDs.
>>
>>>>http://wpnet.us/radio/guts.jpg
>>>>http://wpnet.us/radio/closeup.jpg
>>>>http://wpnet.us/radio/display.jpg
>>
>>>>Parts fromhttp://www.digi-key.com
>>
>>>Has anyone found LED "bulbs" that work with indirect gauge lighting? I
>>>tried some on the Porsche and they were dimmer than the stock incandescents.
>>
>>>In fact, I've been pretty disappointed in all the LED products I've
>>>tried; I bought some LED 1157 bulb "replacement" and they were
>>>hopelessly dim from straight on and worse from an angle
>>
>>>nate
>>
>>>--
>>>replace "roosters" with "cox" to reply.
>>>http://members.cox.net/njnagel
>>
>>No problem at all on the radio buttons, indeed they are quite bright and
>>I'm running them at about half their rated current.
>>
>>If you have a situation where the light guides are relying on side
>>output from and incandescent, I'd use surface mount chip LEDs and
>>arrange three of them standing up in a cluster facing outward to get the
>>correct light distribution.
>>
>>If you're replacing larger bulbs like the 194s then just use the T1 LEDs
>>arranged the same way. All the LED specs are on the Digi-Key site, as
>>well as those for most incandescents, so it's pretty easy to compare the
>>MCD ratings.- Hide quoted text -
>>
>
>
> That's exactly what I did; I was using 194-format bulbs in the dash of
> the Porsche and bought some that sound like you describe I think from
> superbrightleds.com - they *were* red FWIW but the light output was
> very disappointing.
>
> for my current issue I found some 1816s at my FLAPS on my lunch hour,
> I'll try those in place of the unlabeled bulbs in the Sunpro gauges
> (they appear to be 53s or something similar) and see if they provide
> acceptable lighting after dark.
>
> nate

Followup: the 1816s did improve the lighting, but the design of the
Sunpro gauges is simply inferior to the VDO. Now I think the bulbs are
roughly comparable (the 1816 draws 4.29W while the 158 used in the VDO
gauges draws 3.36W; the bulbs originally in the Sunpro gauges were
unmarked but look like a 53 and were pretty dim) but the VDO gauge has
an extra reflector behind the bezel to deflect more light onto the face
of the gauge, while the Sunpro gauges do not - so when you look at them
at an angle (say, when they're mounted in an under dash gauge panel) you
see a bright crescent of light at the edge of the gauge but the face
still isn't as well illuminated. Plus the 1816 is simply the brightest
bulb I could find in that format; the 158 in the VDO gauges could easily
be replaced with, say, a 194 or W5W if I needed to make it brighter
relative to the dash panel so that I could dim the dash panel to a
comfortable level and still have the auxiliary gauges legible.

Lesson learned; next time I'll spend the extra $10-20 a gauge to get the
VDO. I figured "hey, it's just an old work truck, cheap gauges will be
fine" but sometimes nice stuff really is worth it.

nate

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