TMCC Headlight voltage?

Go to the Lionel homepage, go to customer services, replacement parts, and then type in 6-28078. Select the engine link and scroll down to the lamps. There is an icon for pictures of the parts. Select the one that matches what you need. Recommend buying two. Keep in mind there is a $9 shipping charge. You may want to check out your local hobby shop repair department to save the shipping.

The Lionel TMCC headlight outputs are 12 volts.

For some reason the headlamp for this locomotive is an 18V 50ma bulb, so you may want to use an 18v lamp to replace it.

I know some of the boards have variable voltage for conventional mode, I don't remember where I heard that. I get 12V coming from a standard R2LC-08 for the headlight voltage in command mode.

gunrunnerjohn,

There is nothing wrong with the bulb. I tested it with 9v battery. Bulb works fine.

So I am not getting power. I did a reset. No change. Everything else works great.

Which pins on the R2LC yield the 12volts for the headlight?

Pins 13 and 14 are the front light AC hot on the R2LC board. 12 volts should be generated, but recommend checking continuity before checking the voltage out puts with a "live" engine. Recommend checking continuity from Pins 13/14 to the ground pin on the R2LC board. Then check continuity from the pins to the head lamp, head lamp to ground pin. You may want to pull out the LECCO connector for the head lamp from the mother board. Check for continuity between either wire at the LECCO connector and the loco shell/body. If you have continuity between the wires and shell/body, there is a short in the wires. Because the bulb works, sounds like there may be a break in the wire insulation. If you cannot find a break in the insulation, check for pinches. The wire could be broken inside the insulation at the pinch. I would assume the wire is the issue before assuming you have a bad R2LC board.

Also, check to see if one of the bulb wires touches the boiler front when it is in place. Sometimes there is a gap between the LECCO connector and the bulb which allows the shell to touch one of the bulb leads if the bulb fits loosely in the boiler front. A little LOW temperature hot glue can hold the bulb in place and provide insulation.

Gunrunner John - any other suggestions?

Hank

Did you try "aux2"

Bill

Bill's on the job here, AUX2 toggles the light, it's bit me a time or two.

Great point Bill - simplest solution first!! Hank

AUX2 doesn't do anything for the front light. It works on the rear light.

Hank TTR, Which pin on the R2LC is the ground that you refer to above?

Thanks.

If you disconnect the bulb do you have a reading at the pins on the connector from the mother board?

There is a small triac MAC97 that is used for lighting. If blew this could be replaced.

I would check for good connections and no grounds on the harness run to the light bulb. G

ctr - AUX 2 turns the headlight on/off. Does the rear light stay on all of the time? The rear light should go off when loco goes forward. If the rear light stays on all the time, the front and rear lamps may be installed in reverse at the motherboard - but that would not explain why one works and the other does not work.

When looking at the BACK of the board, pins 3 & 4 are AC ground (outside rail/ chassis). Keep in mind the bottom right square pin is pin 1. It is AC hot.

Recommend testing only continuity directly from the board pins. If you have to test the voltage with the engine "live", please do so at the head lamp to avoid shorting out boards with the meter probes by touching the bare pins.

Any thoughts Bill or GunrunnerJohn?

Hank

Since this is listed as having an R2LC-08, you could try one from another locomotive to see if you have a board issue or some wiring issue. Any R2LC from -08 on should at least light the lights, I've replaced the -08 with a -11 and a -13 and successfully run in several locomotives. My approach at this point would be to isolate it to the board or the rest of the wiring. The rear light is on the tender, right? Since this is a wireless tether, so that light is powered independently and not directly from the R2LC.

If he has a pinched light harness and swaps in a new R2LC he will blow the TRIAC on that board also.

Need to ensure no short on the light harness.

Hank, AUX2 turns both off, not just headlight. On most of these later issue engines, the harness has the wires connected so most likely not a swap of reverse and fwd. Either way changing direction doesn't work. So this is either a wiring issue to headlight or a Triac that opened on the R2LC.

There is a method to test the triac also if you have a voltmeter with diode function. G

I am confused. When I trace the circuits on a R2LC (-04,-07,-08), the track power feeds the 5 Triacs that control the lights, couplers and smoke. The lights and couplers go through a Polyfuse first, but the smoke feed comes straight from the track. Does the R2LC supply only half-wave outputs?

Time to pull out the 'scope....

It depends on the programed mode type, Steam, Diesel etc.

Smoke is halfwave excepet for boost, then fullwave.

Head Light is halfwave with polarity changing direction in some modes.

Like you said a scope will show all of the options and should be documented.

Carl

Dale, If you check it please post the info. My understanding is also as Carl stated. This is also why the LCRX could be used to control multi color LED with different combinations of Commands.

CTR, Any updates on your problem? G

The guys covered everything very well. Did you check continuity from pins 13/14 on the R2LC board to the connector on the motherboard where the headlight connects as GGG mentioned? I always start there with a headlight issue. Many times it turns out to be a bad trace on the bottom of the motherboard. Blown away traces on the motherboard are not uncommon. These can also be repaired with a jumper wire and will outlive any motherboard trace.

I've never been able to get anything but a negative going half-wave from the R2LC, what mode gets you positive going output?

I had to replace the Molex connector to my driver board on my Lionel Chessie U30C, 6-18292 and all is well except......... the reverse light (LED) stays on all the time.  I am getting 16 vac continuosly to the back light as measured at the light connector and on the motherboard.  I have done mutliple resets using the Aux1 then 8 as well as 6.  The Aux 2 successfully turns the front headlight on and off but nothing for the rear. The front headlight get ~9 vac on and off to make it operate.  

 

Did a fry a Triac on the RL2C-08?   Any way to confirm (pinning out) with my meter before I buy another?   I will need some direction on the pin numbering convention (left/right, top/bottom row) on the RL2C. 

 

16VAC all the time sure sounds like the triac is dead.  Have you tried a different R2LC from another locomotive?  That's the first thing I'd check.  Obviously, make SURE you don't have anything shorted on the output to the rear light, that will smoke the triac in a hurry!

I did try another R2LC board (not sure of the model and it does have differenct components).  The rear headlight did not stay on all the time.   However, all the lights flickered on and off so I did not let it go for long.

 

It may have been shorted momentarily during reassembly (dang spring style cab/chassis connectors), but it should not be shorted now with the light nice and bright, right?

If the other R2LC board made the lights flicker like that, I'd be looking for wiring issues.  Have you done basic things like use an ohmmeter to ring out the connections from the R2LC socket to the lights, and also see if they're shorted to anything else?

 

See this diagram, check pins 9 & 10 and make sure they ONLY go to the rear lights.  One will be common and go everywhere, forget which one it is.

 

Thanks Gunrunnerjohn for the diagram.  I am saving that in a good spot.

 

I am getting straight track voltage 18V on pin 9.  I get it on the motherboard wire connector and at the light contact block.  This is without any of the wiring in the cab even connected.  So it seems like the problem has to be eminating from the R2LC.  I don't know what a triac does but would a failed one cause the voltage to go high like this? 

Just on a lark, pull the R2LC out, set the thing on the track, and see if you still get the voltage on the pin.

 

I'm thinking it's coming from a short under the motherboard or the like.

A TRIAC is just a switch controlled by a signal.  3 legged device that can pass AC.  Yes, a short can cause the triacs to fuse in a shorted position so it is on all the time.  THey are MAC97.  Look for a burn mark on them.  They look like small cans with three legs.  G

Pin 21 is a master clear.  Feed from a transistor on the board.  G

Since the other R2LC didn't work properly, I'd be looking for a short outside the R2LC.  Most of the time, those triacs fail open if they've been overloaded.

Did you have a tech put your R2LC board in the board tester? If the R2 is bad, replace it, don't waste your time messing with it.  They are cheap.  I have seen many TMCC headlights with 18 volt bulbs.  Guys would give up on troubleshooting and wire an 18 volt bulb to the rollers and ground.  Can you control the light from the board?  Answer is no.  Will the headlight work?  Answer is yes if wired as mentioned.  I see no reason to ever turn a headlight off and I could live with that fix all day if I could not find the problem.  It is an option. 

I do not have any wired that way but it is a bandaid fix.  Older TMCC locomotives are showing up with bad motherboard traces.  I would go with John on the motherboard if I was unable to put my meter on things. 

I would say you have a bad Radioboard or a short to power. The only way to read voltage at pin 9 or the spring pad is to have a load placed on the R2LC.

 

Bill

I've put triacs on a number of R2LC boards, it's easy and saves the $35-40 for a new board.

 

OTOH, I don't think this problem originated with the R2LC, even though it may be damaged at this point.

John, I see your point.  It is worth going your way if paying retail.  I am fortunate and do not have that payment program.  I keep every bad board I take out of any locomotive (MTH-Lionel-other) in the case  I ever need a board component.  I have many R2 and R4 boards and plan on putting them in the test fixture one day and doing any fixes you have mentioned. 

I have several R2LC boards, all have been restored to full operation.  It's nice to have parts to swap in when you're diagnosing something.

Not necessarily true with the MAC97.  I have had more than a few short closed.  Low current and then they fuse.  So it can go either way.  It is possible a partial or momentary short on your headlight.  Check the wires closely, especially where the two wires join the bulb, and or anywhere the wires are in a position to be pinched by the shell.  G

Hey, Marty are you coming to the LCCA conference in Norfolk?  If so, bring your circuit board tester an Lionel Tech manual, and I will buy you diner and A drink:-)!  G

Did you have the antenna connected?  So you regained headlight control, but had flickering lights.  Which could be a reception issue.   Is this other R2 a known good board?

 

The TRIAC is about $.20 and easy to replace on the first R2LC.   G

GGG, I am going to try to make it.  That is a deal.  The last time I saw Norfolk was while I was in the Navy.  I always liked that city.

 

Guys, remember when you throw in another R2LC board in your engine it is a good idea to reprogram it with the code for your engine.

Sorry I disappeared for a while.  Didn't mean to resume this thread and then go silent.  I had to attend a graduation celebration out of town.  I could read the thread on my droid smartphone (Verizon) but it would not allow me to post a reply.

 

I think that it is somewhat easy to short out the front or back headlamp circuits at the contact block.  These U30Cs require the contact plate (screwed to the frame) and the contact block (press fit in cab) to be at a skewed angle.  You also have to carefully bring that through and around the smoke unit.  So it is very plausible for one of the springs on the contact block to end up touching positive and negative at the same time. 

 

I can go fishin in some of my early 2000s diesels for another same model (08) R2LC board.  Should I try the good board on the U30C or put the suspect board in the other loco?  Which has less chance of causing less damage?

 

I inspected the suspect board.  All the triacs look like they still have their smoke inside.  No burn marks on the board that I can see with magnifying glass. 

Before sacrificing any more R2LC boards, I'd suggest you remove the R2LC and do the voltage measurement I previously suggested.  You should have nothing but a light bulb to track common without the R2LC installed.