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Flickering Autometer Gauge Faces

8K views 7 replies 3 participants last post by  McSpeed 
#1 · (Edited)
I just installed some Autometer Sport Comp Digital gauges (the two on the right):



I get 12v dimmable power for the gauge faces from the positive ash tray light wire BUT unless the dimmer is all the way up, the voltage wavers a little (according to my multimeter). The wavering voltage causes wavering brightness on the gauge faces, which is distracting. Note that voltage from the fuse box is rock solid.

Autometer thought it might be a bad ground, but wouldn't that make the fusebox voltage waver as well? Is the ash tray wire too small? Is there a beefier wire I can tap for more dimmable current?

Thanks for any input!

(Sidenote: the wideband sensor is not hooked up yet so the gauge pictured is just making up AFRs)
 
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#3 · (Edited)
lol thanks

Additional troubleshooting detail:
The dimmer wheel changes the dash lighting voltage from like 1v(?) to 12v. At some arbitrary partial brightness setting I measure ~3.xx volts from my dimmer source. But of course it fluctuates slightly. The voltage fluctuation follows an oddly consistent cycling pattern of 3.35v to 3.44v to 3.56v to 3.35v etc. over and over. Doesn't seem random...

I wonder if this is just how the dimmer works and these gauge faces are just sensitive...

Could be the multimeter too though, I guess...
 
#6 · (Edited)
Aha! I talked to Autometer again and: basically the natural slight shakiness in the dimmer voltage is enough to affect the gauges' LED lighting brightness.
However, this inline module can smooth out the voltage: Auto Meter 9114 LED Lighting Dimmer. Sweet!

(At first I thought this meant that the gauges would have their own dimmer separate from the main dash dimmer, but fortunately it works inline with the dash dimmer.)
 
#8 ·
Followup: The dimmer module helped enough so that I'm ok with it. There's still some pulsing but it's not distracting. If I really wanted to I could get the lighting power from the fusebox and dim it with this module, and it would be solid.
 
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