Lunar Gauge Resistor ?

[mixedup]

I have found in searches that with the lunar gauges to match the stock dash closely you want to put in a 100ohm resistor - went to radio shack and found they have 3 types - 1 watt, .5 watt or .25 watt

I have 3 guages that I want to wire to the rheostat - what resistor do I need and can one be wired to all three in line or one for each guage?

Thanks for your help

 

[Emil]

Without any additional information I can't tell you for sure. Putting in a higher wattage resistor won't harm anything, it's only disadvantage is it's size. I'm pretty sure you would need a resistor per gauge but like I said without any more info I can't be sure. Do you have a link for the website?

 

[EatonEggbeater]

You'll need one for each gauge, unless you want to compensate fro the culminative current draw.

Use a resistor rated for the load, Emil's right, too much resistor wattage doesn't matter, too little does.

 

['03 Sonic Blue]

Not knowing the wattage required when installing mine, I just tried a 50 ohm 10 watt resistor I had laying around. It did not provide enough resistance. I ended up with one 100 ohm 10 watt for three gauges. They're still a little brighter than the factory gauges. I'll be adding a 4th, so it will bring the brightness down a little.

Now that I've become curious, I went out and measured the combined current draw for the lighting for the three gauges. It's 76 mA (0.076 A if you're left handed) for all three with the 100 ohm resistor in series with them. So you should be able to about fill the passenger compartment with Lunar gauges and run them all off one 0.25 A resistor. edit: (see correction a few posts down) They'll just get a little dimmer for each one you connect.

--Mike

 

[BLK03SVT10TH]

I made this Dimmer up and hooked it up to all 5 of my Lunar Guages.

It looks like this when they are working.

 

[TRBO VNM]

Originally posted by BLK03SVT10TH
I made this Dimmer up and hooked it up to all 5 of my Lunar Guages.

can you post the part numbers of what you used. I think you said in your other thread it was all from radio shack.

 

['03 Sonic Blue]

Originally posted by BLK03SVT10TH
I made this Dimmer up and hooked it up to all 5 of my Lunar Guages.

Looks like a pretty good match!

--Mike

 

[EatonEggbeater]

That's a good way to determine the resistance needed, put a potentiometer in series with one lamp, adjust the pot to where the lamp's at the right level (car running) and read the resistance across the pot with an ohmmeter.

Buy resistors that are at, or a little bigger than this reading.

 

['03 Sonic Blue]

Originally posted by '03 Sonic Blue

Now that I've become curious, I went out and measured the combined current draw for the lighting for the three gauges. It's 0.076 A for all three with the 100 ohm resistor in series with them. So you should be able to about fill the passenger compartment with Lunar gauges and run them all off one 0.25 A resistor. They'll just get a little dimmer for each one you connect.

--Mike

Some were probably wondering what I was drinking when I wrote the above. Well, nothing, but it would have been a good excuse since resistor power capability is rated in watts not amperes. Since I was sober, that just makes me an idiot.

So, in correction:

0.076 A across a 100 ohm resistor gives a voltage drop of 7.6 V

.076 A multiplied by 7.6 V yields 0.58 Watts.

So you should probably stick with at least a 1 watt resistor.

Sorry if I misled anyone.

--Mike

 

[vipergts281]

I made this Dimmer up and hooked it up to all 5 of my Lunar Guages.

It looks like this when they are working.

Do you have instructions and part numbers for your dimmer there?

Thanks. :beer:

 

[BLK03SVT10TH]

Lunar Gauges - Auxiliary Dimmer

It was marked 64W100R-K and supposed to be a 0 to 100 Ohm 10 Turn Adjustable Potentiometer so it allows for very precise adjustment.

I just plug this in between the Add-A-Circuit and the 5 Wires running to the 12V Power for each of the Gauges.

 

[vipergts281]

Lunar Gauges - Auxiliary Dimmer

It was marked 64W100R-K and supposed to be a 0 to 100 Ohm 10 Turn Adjustable Potentiometer so it allows for very precise adjustment.

I just plug this in between the Add-A-Circuit and the 5 Wires running to the 12V Power for each of the Gauges.

So you bought it from Autometer?

Do you have a pic of it hooked up in your car?

 

[BLK03SVT10TH]

So you bought it from Autometer?

Do you have a pic of it hooked up in your car?

Not from AutoMeter, I got it at an electronics shop. The install is really basic. It plugs into the Add-a-Circuit on the Fuse Panel, then all 5 of the small diameter white wires that go to the lighting on the gauges are bundled into one connector that plugs into the other side of it.

 

[vipergts281]

OK, thanks.