I posted this in the ZElectrical Tech thread as well but thought it should be in here as well... The problem is,

I have a 2001 FXSTD (carburated) and have an issue that is stumping me. I realized this problem after I had installed some LED turn signal bulbs. When I turn on the ignition and after my "engine" light goes out, my turn signals flash 4 times then go out. They never did that before I changed the bulbs. I put the original bulbs back in and it still does it. I have had a HD brake module installed for about 3 yrs with no issues. I disconnected that and tried it again and still the same thing.
On a seperate issue (not sure if it is related) I was on my last ride of the summer and my voltage regulator went out. Battery was drained and once I got it going the speedometer would work intermitently and lights were very weak. I have replaced the regulator but have not been on a ride since. Are these two things related? Any help in this matter is GREATLY appreciated.

 

It could be a code flashing...
My 01 FLHTC does the same thing,Blinkers flash 4 times...the first time it did this they replaced the module then it did it again and it was a sidecar code they reset it and now it does it again....No chargeing problems tho...

 

Does bike start and turn signals work? You either have a trouble code in history (from the regulator going bad-from either low or high battery voltage) or a current code (from most likely from the LED install?). Hold in the trip reset button on the speedo while turning on the ignition switch. The odometer display will now show "d01, d02..." all the way up to "d011", then "PPU" and a number (believe it's the IM part number). Check to see if your bike has any other numbers besides the d-0's (i.e.: d035, d031, etc.). Write down this number and the PPU number. Don't know if you can clear histories by holding in the button again when the code is displayed or if the dealer has to clear but give it a try. That's pretty much all the info I have without doing your legwork for you and looking up but there are threads in this forum and the internet regarding the old-style scanner trouble codes.