Conrail SD, 3 blinking lights

I had the same issue with the same engine. Was still under warranty but I did have to send mine into Lionel to get the new smoke unit motor installed. If it's still under warranty it's a simple call to Lionel to get a return authorization number. It will just cost you to ship it down to them. If not under warranty I'm not sure what the cost will be to you, but you might get brave and try and replace the motor yourself. 

I had the same problem recently on a different diesel. It was under warranty, but I replaced the bad smoke fan motor myself. It wasn't that difficult and it all worked out just fine. The motor I replaced was working, so I don't really know why I was getting the 3 blinking lights? However, the motor replacement solved the problem and no more blinking lights. 

I didn't want to risk causing more damage in shipping when I thought I could fix it myself for a couple of bucks. I already had an MTH smoke fan motor which looked identical to the one in my Lionel engine so that's what I used.

The cost to send my Legacy 990 from K.C. to Lionel in N.C. a couple months ago was around $20 using UPS. I used a much smaller box than the original 990 box. I imagine an engine would be a bit more due to added size and weight. Maybe quite a bit more? Shipping has really gone up lately.

The motors that yield the blinking lights frequently draw excessive current, I had one that draw around 400ma at 5V, the normal would be around 10% of that, 40-50ma!  Needless to say, I got the blinking lights.

I suspected something like that, but I never checked the bad one, just replaced it. Thanks for the info on the current readings, I would bet that this was the problem with mine as well. The fan did not appear to be binding and everything else seemed fine, just couldn't get rid of the 3 blinking lights.

Jon Z. from Lionel tested a bunch that I had replaced, and that was the predominant failure.  I truthfully hadn't thought of checking current since they ran normally.

That's a good ID of the problem, doesn't get any better than that.

Is the Lionel smoke fan motor the same one as MTH's? They looked identical right down to the markings so MTH is what I used for replacement. Someone here was kind enough to get me some MTH motors a while back so I just happened to have one handy.

Also, are the Lionel wicks are the better smoke wicks or is it MTH? I think maybe you, Marty F and others have stated a preference of one over the other, but I keep getting these mixed up as to which is the preferred wick.

I've used MTH motors where they fit, they're the same specifications, but I believe the shaft is a big shorter.  It hasn't been an issue where I used them, and the MTH motor doesn't fit for the Lionel short motor with the angled mounts every time, they're sometimes a pretty tight fit.  Also, the MTH motor is a bit longer.