In oredr to remove the shell you disconnected the headlight wire(s)? Some F units had dual lamps, others only one.
So can you use an AA battery to test the lamps? That would eliminate at least one diagnostic hurdle.
The sole red wire ‘might’ be the antenna for the DC sound activator which was a little remote button that could activate the horn and bell while in DC mode. (Sound Genie®)
You have other things working against you as well, unfortunately. One being this locomotive is close to twenty years old. The pair I bought from Athearn that had this MRC decoder were from 2006.
Another downside is that MRC was not well loved for their ‘quality’ control in the decoder market. Some had good luck but many users had problems with them.
It would also help if the OP (if they’re still with us?) would say exactly what engine they bought - with the Athearn model ID we could look up the engine and have a better idea what it has (single or dual headlight, which decoder, etc.)
If it is an MRC engine, F0 should not affect the sound. Not aware of any decoder that uses F0 that way, but maybe there are some?
MRC instructions say to add a 1k ohm resistor is using a 1.5v bulb or an LED for a light. Could be the original owner tried adding such a light without a resistor and it burned out?
Could try hitting F3 too. F3 turns on the accessory lights (Acc 1 and Acc 2), just to see if the original owner hooked the headlights up to those wires for some reason.
I’m hoping that the OP tried the engine moving. Some decoders default to having the headlight go to dim whenever the engine stops. If the CV controlling the brightness of the dim setting is set too low, could be it appears to go out - but would be on if moving. Plus move it in both directions, in case the headlight is set to directional.
Also check CV 120 if it is MRC. That is the brightness setting. If that is very low, that might be why the light isn’t shining.
Sorry, fellas. I’ve been trying to find replacement bulbs. The model ID is G22145, and it does have an MRC decoder. It has a single headlight. According to brochure that came with the unit, “Directional lighting” is F0; double clicking F0 turns the sound on and off. I removed the bulb and tested it with a battery. It lit for a second but hasn’t come on since. (The F3 is “Air release.”) And I tried the headlight with the engine moving and at idle, forward and backward. Thanks for the help. Next: where to get LED replacement lights. I found some at Scale Sound Systems. Anywhere else?
Ahh, thanks for that reply, My first thought was that you tested with a 9V battery and blew out the 1.5V bulb. So, now I wonder why that bulb lit the first time but not again. You need to verify that the bulb is still working or get another one. Good luck.
I like to use Evans Designs LEDs. They come in several sizes and colors, 3mm or 5mm ‘warm white’ are good for headlights. Nice thing is they come pre-wired with resistors so you can use any power up to I think 16V and it won’t burn out the LED. You can even connect them direct to DCC track power like for a trackside building’s lights.
Before you buy any LEDs, open up the shell and look at the size of the opening in the light housing. On my Athearn Genesis F3As, the housing was too small for standard 3mm LEDs. Maybe 1.8mm LEDs would fit, but I didn’t bother to find out. So, I bought some SMDs (I see that Scale Sound Systems sells those). The SMDs are excellent, but very bright, very tiny, and somewhat difficult to handle because of their size. Athearn also sells LEDs specially designed to fit in the existing housing. So, just be sure to do your homework before proceeding to buy replacement lights.
Hmm. Not going to argue with the owner, so I hope he is right. It is possible to “turn” an LED, so maybe that is how this product was finished. Good luck.
Evans Designs makes a 1.8mm ‘flat’ LED that is very small and very bright. I just used one in and old Stewart F-unit to light the lower headlight where there was very little room. (I used a 3mm in the upper.)
The whole issue with the Athearn Genesis F3A, in my experience, is the size of the opening in the housing where the bulb is inserted. It is very small. To complicate matters even more, Athearn has recently changed its long-standing policy of using tiny 1.5 incandescent bulbs, changing to LEDs. So, it would be prudent to open the shell and look at, and measure if you can, the size of the opening. One possibility if the hole is too small is to ream out a larger opening. Comparisons to other locomotive manufacturers such as Stewart, etc. are irrelevant because the Athearn Genesis housing may well differ and probably does differ. My point is that older Genesis models may differ from newer Genesis models. It would be prudent to check before you buy replacement LEDs.
Rich, yes, the opening on my loco clearly is less than 3mm. I’m going to try a 1.8mm LED bulb. For the lights above the number boards, I’m going to use a Z size LED chip. I assume I can/should use the same connections on the decorder as the headlight.
Let ud know how the 1.8mm LED works out. I do not own a set of micro calipers so I had no way to check the opening, but it sure looks smaller than 1.8mm on my Genesis locos. When I used the SMD LEDs, they were so small that the opening in the housing was too large. LOL. So, what I did was to cut out a tiny piece of silver duct tape to cover the opening and then inserted a needle point into the covered opening. That worked just fine, holding the SMD LED in place without falling out of the back of the opening. The SMD LED is so bright that no one could possibly see that small piece of duct tape.
Generally, that is correct. However, on my Genesis locos that were DCC ready, when I installed TCS decoders, I got fooled. The factory wiring connected to a 1.5V function output tab, and the newly installed LED that replaced the 1.5V factory installed incandescent bulb wouldn’t light. Some kind soul on the forum said, hey Rich, there is a 12V donut hole on the decoder. You gotta use that one. Duh! So, keep that in mind in the unlikely event that you encounter the same setup.
