Speedhut Dash Light Mystery

[cgundermann]

Just down to soundproofing/carpeting and I noticed my custom made Speedhut Dash lights do not illuminate anymore. Lots of threads on wiring these gauges to the Ron Francis (RF) wiring and I’ve spent the last two days under my dash checking and even reconnecting junctions to ensure they are solid. I have the Speedhut’s supplied dimmer/inverter and when I turn on my lights - my red needle on all of my gauges lights up and I realize that the FFR light switch I’m using only turns the needle lights on. When I turn the Speedhut potentiometer/dimmer - nothing. Every other function of all my gauges works properly. Dash light fuse is fine.

I have both the RF white dash lights (two with this RF kit; one to speedo/tach & other to the rest of the gauges) connected (guess I could have only used one) and they are spliced into the white Speedhut daisy chained wire and the white dimmer/inverter wire. The gauges and dimmer are grounded and the dimmer is plugged in to the Speedhut chain at the speedometer.

Multimeter at the potentiometer is showing close to 12 volts entirely through its turning sweep. The only thing that this non-electrician thinks is maybe the inverter module or potentiometer assembly?

Plan on calling Speedhut tommorow, but any thoughts are greatly appreciated!

Chris

[Papa]

Silly question, but is the dimmer all the way off on the headlight switch?

[cgundermann]

The FFR headlight switch dimmer/knob only turns the needle illumination on or off when using the Speedhut gauges. The Speedhut augmented dimmer adjusts the gauge brightness; but, yes - checked that multiple times...


Chris

[edwardb]

The FFR headlight switch dimmer/knob only turns the needle illumination on or off when using the Speedhut gauges. The Speedhut augmented dimmer adjusts the gauge brightness; but, yes - checked that multiple times...

Chris

Actually, when twisting the headlight switch dimmer knob, both needles and backlighting will switch off together when the supplied voltage drops below a certain threshold. Neither dim via the headlight knob, just switch on and off. Both the needles and backlights should be supplied by the same gauge light circuit from the RF harness through the headlight switch.

The Speedhut backlighting requires AC which the inverter provides along with the knob for adjusting the brightness. This explains in more detail: https://www.speedhut.com/faq.i#how-d...ng-system-work.

If you have lit needles, and +12V going into the inverter with no backlighting, sounds like the inverter could be the problem. If you're trying to measure the output of the inverter, you'll need to measure using the AC range of your multimeter. I haven't personally experienced it, but I've seen reports from others of that part failing.

[Jeff Kleiner]

... I haven't personally experienced it, but I've seen reports from others of that part failing.

Yep, I've had 3 of them go south on different cars. I'd like to think the quality has improved because I really like their gauges but not the high rate of failures I've experienced with senders, clocks and the inverter.

Jeff

[cgundermann]

Thanks Paul & Jeff, I will call Speedhut in the morning.

Glad I’m not losing my mind...

Chris

[cgundermann]

Speedhut has awesome customer service, - they are shipping out a whole new dimmer/inverter assembly!

Chris

[cgundermann]

Speedhut has a new & improved dimmer/inverter unit. Just installed it and that fixed my issue.

Chris