LED Instrument Lights

[bighealeysource]

Merry Christmas all,
Got a weird problem installing some Moss LED dash/instrument light bulbs. Got one installed on the speedometer okay and works fine. Installing is just unscrewing the old 2 watt bulb and screwing in the new LED bulb. On the tach location the 2 watt bulb works, has power obviously, but when I screw in the LED get nothing. Checked to make sure the new LED was working and it is, but will not light up! Any ideas on this minor problem?
Thanks,
Mike

 

[Bob_Spidell]

Tachs have two bulbs: backlight and charge indicator, which one are you referring to?

Supposedly, the charge indicator should not be an LED--it indicates a voltage differential between battery and generator--but I use one and it works fine.

re: "Checked to make sure the new LED was working and it is, but will not light up !"

A bit of a contradiction; if it works 'on the bench' but not in the car it could be a polarity issue; are you + or - ground? Pos. gnd. LEDs are a bit harder to procure.

 

[bighealeysource]

Hey Bob,
It's the backlight bulb and it is negative ground. Got one installed on the backlight for speedo as mentioned and it works fine.
Thanks
Mike

 

[Gliderman8]

LED's have to have the proper polarity to work.

 

[Bob_Spidell]

Hey Bob,
It's the backlight bulb and it is negative ground. Got one installed on the backlight for speedo as mentioned and it works fine.
Thanks
Mike

Did you swap the speedo light for the tach light? If so, what happened? Did you check the tach's ground with a voltmeter (or continuity checker)?

 

[bighealeysource]

Hey Bob,
No I hadn't tired either of those two but will ! I'll let you know as agree it does sound like a grounding issue. I checked on my Moss invoice and did get the correct negative ground bulbs.
Thanks
Mike

 

[McTriumphs]

Merry Christmas all,
Got a weird problem installing some Moss LED dash/instrument light bulbs. Got one installed on the speedometer okay and works fine. Installing is just unscrewing the old 2 watt bulb and screwing in the new LED bulb. On the tach location the 2 watt bulb works, has power obviously, but when I screw in the LED get nothing. Checked to make sure the new LED was working and it is, but will not light up! Any ideas on this minor problem?
Thanks,
Mike

Bad Ground.

 

[bighealeysource]

Hey y'all,
Well, it was as suggested, not grounded properly. The two wires from the small bulb holder were apparently reversed. Got enough juice to light up the small 2 watt standard type bulb but not the LED. Once I connected them back up the opposite way, LED works great.
Thanks for all the help,
Mike

 

[Bob_Spidell]

Not the 'juice;' polarity. LEDs are 'woke' .

 

[bighealeysource]

 

[Legal Bill]

Mike, how much brighter are the LEDs? Do you feel they were worth it?

 

[bighealeysource]

Definitely on the tach, not as much on the speedometer but now I can see the instrument faces at night !!!

 

[Bob_Spidell]

They're definitely brighter but, because the sockets are at the bottom of the case the dials aren't illuminated evenly (brighter at the bottom).