As long as it physically fits and it the same color as the 3mm one in the other end. Otherwise, physical size is the only difference.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
LED temperatures will never be an issue, regardless or size or type. LEDs just don't get more than luke warm if that much.
Jay
C-415 Build: https://imageshack.com/a/tShC/1
Other builds: https://imageshack.com/my/albums
Cisco Kid
I have used all different sizes of LEDs in similar installations without any problems.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Cisco,
As long as you can center it in the front headlight lens and it won't be protruding through the shell, it should be fine. The size of an LED shouldn't make any difference in regards to temperature.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Darn, in the middle of converting an S3 and ran out of 3mm LEDs. I see I can fit a 5mm into one of the ends.
This may be a silly question, but would there be a problem? Would this 20mA 5mm clear LED in my hand run as cool and fine as my last 3mm in the other end of the loco? The 5mm is about the same physical size as the present bulb so fit will not be an issue.
Thanks