athearn genesis + dcc installation question

[Anonymous]

[size=2]Hi, I am new to dcc and I just got a Digitrax system so i am now in the process of retrofitting my locos to run on dcc.

I have a few f3 Athearn Genesis locos and I am having trouble getting their headlights working. I bought a Digitrax DH163A0 decoder and soldered the 6 wires correctly to the board and it runs ok like normal.

The other two wires for the lights are the problem. I can only get one of them to light up at one time when they are connected through a 1/4 470 resistor back to the pc board. I have tried this with a 1k resistor and the same thing happens. I have also tried using two resistors so that both wires have their own resistor and that doesnt seem to work.

So the question is what am I doing wrong and would it make a difference if i used a higher than 1.5v bulb? could i then avoid resistors altogether? i would really like to avoid using the resistors.

If there is there any one out there that has retrofitted these locos, I would appreciate their help. thanks

Lou

[cacole]

Athearn Genesis locomotives use 1.5 Volt bulbs which must be connected through resistors. If you initially had the lights wired without the proper resistor or the wires were not properly connected, you have possibly burned out the bulbs.

In order to determine if the bulbs are still good, you're going to need a Volt-Ohm-Milliameter (VOM), preferably one with a continuity checking tone generator built in. Disconnect the bulbs from the decoder and check them one at a time.

Your third paragraph is a little confusing, but I think you should have four wires going to the headlights because there should be two separate bulbs in them. Separate the four wires. Hold or clip one meter lead to one of the wires, and then touch the other three wires with the other meter probe, one at a time. If you have a tone generator, you should get a tone when the two wires to one of the bulbs are properly identified and the bulb is good. If using the Ohms function, the meter should give you a reading. If you don't get a tone or meter reading, the bulb is burned out.

If you are able to identify a good bulb, the other two wires have to be the other bulb. Check it the same way. If both bulbs are good, connect one of the wires from each bulb together and then to the decoder's "common" lighting terminal. Connect the other two wires together, and then to your light function terminal on the decoder. It doesn't matter which set of wires are connected through the resistor, but for two Athearn bulbs wired in parallel, you need less than 100 Ohms -- anything between 22 and 100 should suffice, depending on how bright you want the bulbs to be. A higher resistance will dim the bulbs.

Athearn Genesis bulbs are not very good, so I try to replace them. Athearn's bulbs are so small that Miniatronics 12 Volt bulbs are the only ones I have found that will fit.

[Anonymous]

Good Morning Lou:

I've installed the Digitrax DH163AO in six "F" units and have had no trouble other then the first set of bulbs that I burned out. These bulbs are like Cacloe mentioned - 1.5 volt. What a lot of people don't know is these bulbs are 15 milliamp instead of the 30 and 50 milliamps like the Miniatronics. Since the current draw (the milliamps) is smaller you need a bigger resister to cut the voltage to the lamp. Each bulb needs its own resister. I have been using a 1K (one thousand) ohm resister and have not burned out anymore lamps. I don't like the resistors that radio shack carries as they are 10%, I buy mine at an electronics store and pay a little more and get 2%. The % doesn't seem like much but you can see the difference in the brightness of the lamp. Remember your engineer doesn't need this light to see down the track, it's just for you to look at.

As mentioned in the other post the first thing you need to do is see if the lamps are good. The way that I do it is to take a 1K resister and put it in series with the lamp and touch the wires to the track.

I've found out that if I set the DCSX00 (X being 1 or 2) to the "N" scale setting, the bulbs last a lot longer and the trains don't run that much slower.

E-mail me if you have problems:

[e-mail]

Have a good day
Bob