Dash light issue.

Discussion in 'Sparky's corner' started by Dons BS, Jan 9, 2022.

  1. Dons BS

    Dons BS Member

    72 Skylark

    I replaced the dash light with LEDs, hooked up the dash(electrical) and I have lights on the clock and fuel gauge cluster but no lights on the speedometer?

    I have 12v on the grey wire at the speedometer connector…? (All factory grounds are in place and I’ve added a daisy chain ground, as Todd has recommended)

    anyone have an idea as to what I can try next?
     
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Try wiggling the speedometer harness connector. Unplug the 2 sockets, and reinstall them. Which LED lights did you buy? Are they polarity specific? Try reversing them.
     
    1973gs likes this.
  3. Dons BS

    Dons BS Member

    I bought the super bright LEDs…pn 194-BCOB1W for the dash.

    I’ve reseated the LEDs and also tried the old bulbs…nothing lighting up for the speedo, the left gauge back light and the clock lights are on tho.

    I’ll try rotating for polarity but the LEDs advertised that polarity didn’t matter.
     
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    If the bulbs lit before, it has to be something you did while replacing them.
     
  5. Dons BS

    Dons BS Member

    I agree….I’ve been checking my photos and retracing my steps to figure out what I screwed up.
     
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Did you pull the dash forward for easy access? Sometimes, the bulb sockets aren't rotated fully and aren't making contact. Try removing them and turn the 180* and try again.
     
  7. Dons BS

    Dons BS Member

    I’ve had the dash out. A few bulbs were burned out, the clock wasn’t working and I wanted to install the new wood grain decals.


    5ECBA846-2805-4155-975F-82D305C41755.jpeg 735B6303-8E95-4347-94AD-D23C09E89EEB.jpeg A5E02F9A-1D47-44E4-ADF4-1C2539CFA534.jpeg
     
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Are any of the pins on the speedo wonky? Maybe you tweaked one? It's 50 years old, doesn't take much.
     
  9. Dons BS

    Dons BS Member

    All of the pins seem solid…because it’s 50 yrs old, I don’t want to test how rigid they are too much.

    headed to the garage to plug everything back in and see what happens.

    thanks for the ideas
     
  10. Dons BS

    Dons BS Member

    Polarity does matter according to the LED manufacturer….it seems when used on a Buick, it does matter.

    Thanks for the help Larry!!!!
    (Put it on my bill)
     
  11. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Dons BS likes this.
  12. ToddsGS

    ToddsGS Founders Club Member

    Check to see if you have Power with the GREY Light that plugs into the speedometer. IF you have power there then the issue is past that - meaning probably something in the gauge connections. . . . .

    IF you do have 12 volts at that location in the connector you could use a jumper wire to put 12 volts on the correct side of the Speedo circuit and see that does the trick. IF it does then something may be loose in the Pin Connector.
     
    Last edited: Jan 10, 2022
  13. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Todd he fixed it. It was the LED bulbs that he used, they were polarity sensitive.
     
  14. ToddsGS

    ToddsGS Founders Club Member

    Ok, good. We've had some bad luck with LED bulbs on a lot of builds so we kind of shy away from them. Not Dash Bulbs but Headlights, Tail lights etc. . . . Sometimes they work, sometimes they don't and other times the Factory Bulbs were actually brighter than the LED's that were used. It's been a few years now so maybe the current offerings have been upgraded and work as they should.
     
  15. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Yes, I converted all my interior lights to LED. The only exterior lights I converted were the trunk and license plate light. LED can be problematic with the flashers. I'm happy with the exterior lights. Might do the headlights at some point.
     
  16. FLGS400

    FLGS400 Gold Level Contributor

    Since they are such a pain in the A** to get to, before I put the LED bulbs in my dash, I installed the bulb in the little holder gimmick, then tested each one with the battery and some alligator clips to make sure of the polarity and that they worked. Then turned the lights on to make sure they worked in the dash piece before i put it back in place.
     
  17. ToddsGS

    ToddsGS Founders Club Member

    Be really careful and mindful of the headlight switch when you reinstall the dash and when you plug in the connector! The escutcheon is FRAGILE,!!!
     
  18. Dons BS

    Dons BS Member

    Thanks for the input guys….I got the dash working and back in the car yesterday. 3F56E133-6995-4604-A620-30FC2BACDA2F.jpeg 09918017-390C-4214-917D-77C1ADB8E789.jpeg
     
    FLGS400 likes this.
  19. Dons BS

    Dons BS Member

    And, Todd…the clock and wood grain stickers look great.

    thanks again
     
    ToddsGS likes this.
  20. ToddsGS

    ToddsGS Founders Club Member

    Nice work! :)
     

Share This Page