qz16

bulb / LED replacement for gauges

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    So, I am replacing the dash on a 1973 240z.  In the process of putting everything back together I tested the bulbs for the gauges.  I believe they are mini bayonet BA9s 1445.  This is a 3.4 W incandescent bulb.  I think that is a lot of power (watts = volts X current) for so little light.  Anyway, I was curious if anyone has a direct LED replacement for the mini 1445.  The version that I have fits some of the enclosures eg. the speedometer and tach, but are too tall for the gauges and the clock.
    Thanks in advance for your assistance.

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    I installed "bulbs" of this type in a customers 240Z years ago. They were WHITE though - that LED brassy white. Super bright - and they happened to work well with his rheostat. Brightened up his instruments double or more. I've not used a colored LED though.

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    Thanks Steve and Chuck.  I will give them a try and confirm.  Unfortunately it will take a while since they will not deliver to me until 4/21.

    regards,

    ron

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    Gundee,

    Thanks for responding. 

    I am sorry to be the bearer of mixed news.  The URL that you sent has a 360 deg view button, one of images is a dimension view.  This is the url for that dimension view.  https://www.superbrightleds.com/moreinfo/ba9s-ba7s/ba9s-led-bulb-4-led-ba9s-retrofit-car-classic-car-bulbs/6/.  I have some of these and I believe that they fit in the speedometer and tach (will check if you need me to), but they do not fit in the gauges - oil temp, amp fuel or clock.  As you can see the length is 26 mm for this bulb.

    The length of the bulb listed by SteveJ is 18 mm and I believe it will fit everything. 

    ps 1 (3/23/20)
    I just checked and the 26 mm does fit in the speedometer and the tach.

    ps 2 (3/24/20)
    sorry to do this but I did not want to mislead anyone.  I was working on the harness in my dash, and inadvertently put just the slightest amount of tension on one of the bulbs for the speedometer.  It came out of its socket.  So it turns out that the 26 mm LEDs do in fact hit the green lens inside the speedometer and the tach.  I was fooled because one of the bulbs seemed tight enough, but it would be a mistake, in my opinion, to use the 26 mm bulbs anywhere on the dash.  So to tie a bow around this the original incandescent length is approximately 20 mm.  The alternative that SteveJ has suggested (thanks again) is 18 mm.  There is one more critical dimension.  There are 2 posts that extend out of the barrel of the bulb.  they provide a key/locking scheme to keep the bulb in the socket.  I apologize if I am confusing anyone.  Anyway, on the suggested alternative there is a collar.  That collar is no doubt larger than the socket, so the distance from the post on the barrel to the collar could be, likely is, critical if it is too short then you will not be able to get the bulb in the socket.  This dimension is not available, so I cant be certain that the alternative will work.  I will update this when I get the bulbs that I ordered.  Sorry for the confusion.

    regards,

    ron

    Edited by qz16
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    So some of the LEDs  (SteveJs suggestion -thanks) that I ordered, came early, the clear version is (as luck would have it) still not scheduled to arrive until 4/21.  I tried the red version (brake Light Failure) and the green version (turn signals) and you have to be patient - there is no abundance of clearance when installing the LED into the socket, but it fits.  I then plugged the sockets into the respective holes.  They install as they should and you will have no trouble with them bottoming out in the gauge causing the socket to become dislodged due to vibration ...etc.

    I was going to wait for the clear to finish this portion of the dash effort, but I am not the most patient person and I noticed all of the socket holes have green filters.  I ordered 10 green and used two.  I need 7 to light the tach, speedometer, and the 3 gauge set.  I decided to populate the remaining 7 with the green LEDs.  Could not stand not knowing what it would look like so I wired the lights to a battery.

    Yes the dash is upside down as I am testing the harness.  And yes the gauge faces have a fair amount of dust on them but you get the idea.

      dsh_green LED_1.jpg

    dsh_green LED_2.jpg

    The wiring on this car separated the 3 gauge set lights from the speedometer and the tach with regard to the dimmer.  When I was redoing the harness I tied all 7 bulbs to the same ear on the dimmer - so they all dim at the same rate.  So these LEDs are a lot brighter than the incandescents.  If they are too bright I can dim them down.  I don't recall anyone ever claiming that the z gauge incandescent lights were overly bright.

    Once again, thanks SteveJ - I appreciate the help.

    regards,

    ron

     

    Edited by qz16
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    I'd like to see that in person one day. Did you open up your gauges at all? Pepper and I are just going through some gauges - cleaning, re-spraying the white inside and the black if necessary, and polishing up the scratched lenses.

    Edited by cgsheen1
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    I'm glad it worked to your satisfaction, Ron. From the first of my research, I read that the LED color should match the lens color. I might have used some white LEDs in the center gauge pod, though. It's been long enough ago that I can't remember. The bottom line is that you will be able to see at night. I suggest that you replace the 20A fuse in the parking light circuit with a 10A fuse. The wiring wasn't really up to handling 20A, so if you get a short, you could melt wiring (or a connector) with the 20A fuse.

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    Steve,  That is a great point.  I built a new harness and upgraded all of the wiring, thats what I am testing now.  But lowering the fuse values is something that i missed.  I installed relays and so I can do that in a couple of spots.  I also removed the heater/defroster and AC and replaced it with a vintage air unit, so there is some wiring that is no longer active, as well.  My original wiring was kindling.  I agree with your suggestion on the 3 gauge set.  When the white LEDs arrive I will give them a try.

    Regards,

    ron

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    So, the white LEDs were to be delivered on 4/21, but they arrived yesterday 4/3.

    For comparison (image 1) I installed 2 white LEDs in the Tach and I installed 1 white LED in the center gauge (AMP/Fuel).  The remainder of the gauges and the speedometer has Green LEDs.   Green LEDs populate all gauges in image 2. 

    image: 1

     

    dash_LEDs_1.jpg
     

    image: 2

    dash_LEDs_3.jpg

    Edited by qz16
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    I kind of like the effect of the white bulbs in the center gauge and tach. Are either dim-able? And lastly, why is your car upside down? 😎

    Edited by w3wilkes
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    The website for the LEDs that I bought says that they are dimmable.  I connected my dimmer and there was no discernible change.  So I measured the dimmer.  Mine measures out to be from 2 -11 ohms.

    It occurred to me that this might be too little resistance for the LEDs.  I looked around but I did not have a spare dimmer of any sort.  I could not find any of the resistors that I have foolishly saved over the years on the off chance that I would have them when I needed them.

    Its Sunday, I am trying to be a good citizen and not go out unless it is an absolute necessity.  When I was a kid I had some hobby kits where you build things and do experiments.  Anyway, here is the cool part (at least in my opinion), if you draw a box, on an ordinary piece of paper,  and fill it in with an ordinary pencil you will have created a resistor.  If you put an alligator clip with a wire attached to it on each side of the block you can measure the resistance that you just created.  If you want less resistance put the clips closer together, more resistance – space the clips further apart.

     

    Homemade resistor

    DIY RESISTOR.jpg

     

     

    So W3wilkes – the answer to your question is that the recommended LEDs are dimmable.  I suspect that the dimmer in your Z (mine is a 1973 240z) may not work because the resistance in it is too low.  But if you get a dimmer in the 0 – 1k ohm range you will be able to dim these LEDs.

     

    Here is a comparison:

    LEDs with no dimmer (speedometer, oil/temp and clock) - Green LED

    Tach and amp/fuel) White LED

    dash_LEDs_1.jpg

     

    LEDs with 458 ohms of dimmer resistance 

     

    458_ohms_dimming.jpg

     

    The next image has no dimming, Incandescent lamps in the speedometer, and clock, Green LED in Volt/Temp gauge, and white LEDs in the tach and amp/fuel gauge

    all_3_no dim.jpg

     

    You must take care in picking the resistance value if you mix incandescent lamps and LEDs.  You might be able to get away with using the original dimmer if you have a few incandcent bulbs and some LEDs.  I think I will try to go with one or the other.  My conclusion is that I prefer either the white LED with a dimmer or the incandescent lamps and a dimmer,  I might consider white LEDs in the speedometer and the Tach and incandescents in the 3 gauge set.

    If you have a question dont hesitate.

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    I'm about to do the same and if at all possible, are you able to post link to the white LED's you purchased for all sizes and quantities required.

    I have pulled the old dimmer of the 73 dash. It's buggered. What wattage 498ohm resistor did you use. Shouldn't be much heat generated dur tothelow wattage LED's there but better to be safe and not melt the dash.

    Thanks

    James

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    So, I purchased the LEDs via Amazon.  Below is the URL for the white LEDs.  I would suggest using White LEDs for the illumination of the gauges and the three lamps that light up the climate panel.  I believe the MAP and DOME lamps are different animal and I have not found the box with those fixtures so I cannot confirm that for you.

     

    https://www.amazon.com/gp/product/B01C2SHQAY/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

     

    So there are seven (7) lamps for the gauge illumination.

    Three (3) lamps for what I believe is the climate panel.

    One (1) for the glove box.

    I do not have footwell lamps, but if you do that would be another Two (2) lamps.

    The inspection lamp in the engine bay is another (1) lamp.

    I don’t have seat belt warning, or choke warning lamps, but I believe these are lower wattage, and physically smaller bulbs.  Maybe similar to the indicator bulb for the rear defroster.  As you know this bulb is part of the switch.

    This totals to fourteen (14) bulbs that I would White LEDs.

     

    There are two (2) for the turn signals – I am using green LEDs – same URL -specify green.

    There is one (1) for the high beam indicator – I am using Blue - same URL -specify green.

    There is one (1) for the brake warning lamp – I am using Red - same URL -specify green.

     

    If you use all white LEDs you will need 18.  If you use the same product that I ordered they come in packages of eight (8).  I would recommend that you order enough to have spares as mine took a few weeks to arrive.  Also, I can only list the bulb locations that I am aware of, so you may have a few more or less, depending upon your year and how original your car is after 40+ years.

    With regard to the dimmer, I don't trust the anecdotal value that I came up with.  I believe Steve J is correct regarding PWM.  If you are still going to use an ordinary rheostat then I would probably find something in the 0-1000 ohm range

     

    Hope this helps you.

     

    Regards,

    ron

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