KW no output?

You should be able to down load a schematic. On line. It will show the wiring . 

Been awhile since I have been in one. 

I have a schematic. It makes sense that it would be a circuit breaker trip, as there are no other symptoms and no output anywhere. 

My real question is, is this a “service” item or a simple manual reset of the existing unit? Will I need to replace it? If so I might as well order one now. I don’t like opening a casing and finding that I need parts I don’t have, I’d rather get all ready then open the case.

here is a video of KW transformer operation and schematic!

https://www.youtube.com/watch?v=la-J_8NEkWA

Alan

That’s about what I thought. I’ve had Sportsters for many years and it’s never wise to go anywhere without a couple of circuit breakers in your pocket... once in a while they just don’t reset. Eventually you have them all replaced with modern type ones and the problem goes away. 

There are plenty of people advertising conversions, so I suppose the older ones aren’t available any more, anyway I don’t like using old electrical parts. 

Ok, I’ll get on it. Plenty to do in the meanwhile. 

You can use an automotive circuit breaker in place of the expensive and actually fairly unreliable OEM circuit breaker.

What rating do you recommend? 

Here is a great page on the KW tear down and rebuild. http://www.tranz4mr.com/KW_Re-Build.html

I would use a BUSSMANN 19110 or 22110 10 Amp Circuit Breaker

Ok good info all round, thanks all. 

I’m going away at the weekend for two weeks so I’ll order a breaker and do the whole job when I get back. Cars over here use fuses, not breakers and electronics shops are pretty much extinct, I’ll need to order one online.

ok, press on.

I second the 10A breaker, the KW is really only good for around 140-150 watts output.  Remember, PW transformers are rated on input power, so you need to cut that by about 15-20% to come up with output power.  Also, the maximum power out is only at full throttle, when running at half power, you don't get nearly full power.

Just a idea have you checked the solder joints ? I picked up a KW years ago for cheap as it had the same problem. Turned out to be a broken solder joint on the secondary coil.

One common problem both shared by the ZW and KW is the connector strip and solder lugs burn off the terminal posts. Check the terminal backplate and look for loose binding posts from the lugs. If found, the terminal will need replacing.

Isn’t better to open it up and determine what the actual problem is instead of second guessing what may be wrong with it?

You will kick yourself if it is a simple nil cost fix after spending money on parts you don’t need to buy.

The KW has a new power lead, fitted by the previous owner whose soldering was a lot better than mine, so I’m assuming that the solder joints are good. The symptoms certainly fit, for a failed circuit breaker. 

I found this page http://www.tranz4mr.com/KW_Re-Build.html which contains a lot of detail, and includes an external check for the binding posts, so I’ll do that this morning. I doubt that it’s a failed binding post, as all the terminals are equally affected. 

From experience of the circuit breakers on older Harleys, if it has an old-style mechanical breaker inside the case, it would be worth replacing it with a modern one anyway. I had already noticed an occasional hesitancy so my thoughts were already pointing in that direction. 

I was already thinking about trying one of the Harley circuit breakers, I have a couple of spares in hand but I don’t believe I have a 10A one. 

Anyway I now have a fairly complete check list and some good detail photos to work to, so I’ll order a new circuit breaker on general principles and make a start when it arrives. 

So, the transformer is back on line. Seems to have reset itself. 

I’ve now ordered a modern cut-out so I’ll put the project on the back burner and deal with it if the problem recurs

If you are getting no output on all terminals and the red overload light isn't on and the bulb is good, it's not a bad circuit breaker.  The red light goes on when the circuit breaker contacts are open.

KW circuit breakers are notorious for falling apart. The older style Part 20-22 has layers held together by a rivet which comes apart after 40 years or so. Replace with part number 20-22R for about $8.50 plus shipping from most parts guys.  
Also look for loose wires on the circuit breaker, metal bracket that holds the whistle rectifier disk and as others posted loose wires on the back side of the terminals. 

20-22R is not a standard Lionel part number, but what some parts vendors use to identify the previously recommended BUSSMANN 19110 or 22110 10 Amp breaker.

I think “notorious for falling apart after 40-odd years” is slightly harsh! I’ve ordered a new circuit breaker and I’ll check those other things at the same time.

Actually Trainz4MR is correct, the early breakers literally fall apart. It is put together with a single rivet and the rivet edge burns off the same way the binding posts do, and no longer have the tension to operate. pieces are just dangling there. 20-22R is not an official number, that is Jeff Kane's number. The R is for reproduction.

I was rather thinking that after four decades of use, the term “life expired” might be more appropriate? 

A lot of things fall apart after 40 or more years.