Hey there IM...I'm having issues starting my 1998 Road King Classic FI and I came across this post. I followed the instructions you provided and got a code of 1,6.

That combination is not in your list above. Can you tell me what it means?

For background, the bike got a new battery just about a year ago, but it did sit almost all winter in the bike in an unheated shed with no tender on it. That said, I did start it and ride it in Jan, and then again in March when weather and road conditions allowed. Both of those times it started up relatively easily and drove like a champ. I have owned the bike for going on 5 years and it has about 30K miles. I believe it is all original. I have put no significant work into the bike in the time I have owned it.

Thanks so much.

-Eric

 

I went to my book, chapter 9 , page 9-18, figure 9-12 (diagnostic trouble codes)
Flashreading of 1,6 is code 16
Code 16 is Battery Positive Voltage
* If the light stays ON then it is a constant error.
If the light comes ON after starting and then turns OFF then it is historical...removal of negative battery cable will erase.
Please review your battery cables at all 4 ends of the TWO cables..It could be a loose cable.
Your starting issue could be a loose battery cable.
Please review the cables.
Then come back and let me know in more detail what you mean by "starting issues" if this does not help.

 

This is a copy and paste i share for 1998 RKC regarding common problems:
1-COMMON...Two fuel hoses under tank leak after 10 years. Harley $$$$$$$, Goodridge HDFL005 under $160 USA dollars or LESS total for BOTH delivered if you check google.
The Goodridge lines are less than half the price of the Harley parts and are of good quality.
2-COMMON..speedometer LCD (odometer screen bleed). requires replacement when unable to read miles ridden. Requires cutting about 12 wires. NOT PLUG AND PLAY LIKE NEWER ONES. A retrofit kit is available to make it plug and play but you still need to cut about 12 wires.
It is a different manufacturer from the newer ones.
3-COMMON..Cam position sensor...very difficult starting, lots of cranking but does not catch. A lot of cranking and no start then you wait a second and a quick tap to start button and it starts with very little cranking…look for visible goo (beige) leak under timer cone (right foot) at black wire exit from bottom of cone…You will have plenty of warning…dozens and dozens of difficult starts...remember crank, crank,crank, crank, get angry...crank, crank, crank, get more angry....crank, crank,crank..say mean words...crank, crank, crank...then wait a minute mentioning evil things , then a slight tap of start button and it starts like nothing ever happened...that is when some folks remember to look for the goo mentioned earlier.
4-CRANK position sensor by oil filter (RARE) but if you use a power commander the signal must be 100%..This is very rare...again rare, doubt it is the sensor ever.
5-(MEDIUM COMMON)Tank liner releases at middle section near fuel pump..blocks flow of fuel..loss of power/speed, slow down and piece moves from fuel inlet so bike is OK but then becomes trapped again so cycle repeats.. FREE REPAIR..open gas tank access lid, drain fuel and clean piece out..I would carry the little bit required to remove screw..The book says you need to replace the one time use screws but if you are careful and replace in the same location it will be re-usable at least one time..
6- VERY VERY COMMON...ENGINE TEMPERATURE SENSOR...very common, general rough riding as bike bucks from cold to hot rapidly..$100 part…disconnect plug behind air filter when bike is OFF and idle control motor plunger is IN as emergency bypass. You will need to hold throttle during warm-up.
7- Bikes that are pressure washed or in snow conditions with salt roads or people that added a power commander and destroyed the rubber boot at ECM..GROUNDING PIN ON ECM becomes corroded and requires cleaning.
8-The circle shape chrome cover cap thing with the allen bolt on the starter end will get loose one time and you will chase the rattle a long time until you figure out that under the cover is two 0.15 cent nuts and one is lost.
***-The shift linkage ends SUCK on all harleys and you need to change those yesterday to heim joints look on ebay if on a budget for: Heim Joint Rod End 5/16" with bolts for Harley Davidson as they should be about $10-$15 delivered for both.
****VERY IMPORTANT...THE CRANK POSITION SENSOR USES AN INSERT TWIST AND LOCK CONNECTION. MAKE 100% sure it is tight, zip tied and secure and then tie it one more time.. Located at throttle side of frame behind the PAINTED plastic side cover by seat (remove cover) and hidden by the triangle portion of frame..connector is black and about 2 or 3 inches long and the thickness of a fat pencil.
That thing had me scratching my head for a long time trying to chase an intermittent cut-off over bumps. Side of the road frustration thing..Many shops are unable to identify the simple problem while others waste your money by replacing it when it was only loose.
THE PARTS ARE READILY AVAILABLE for this bike with the exception of the gas tank from either the dealer or aftermarket.
I would imagine you have the service book or will get the service book for this bike from Harley for about $50 99483-98 . Finally if needed, get the book & read chapter 9.
You can review check engine codes with no tools by following a simple sequence.
I would review the fuel lines. If you do NOT have the goodridge lines HDFL005 then I would consider carrying some in your saddle bag. Rarely does a dealer stock the Harley ones.
Consider using regular Dyno oil as the synthetics are too good at locating leaks.
ONCE AGAIN, Please review the CRANK position sensor connector.
The CRANK sensor starts at oil filter and runs along one side of motor to the other side of bike and then runs up frame to behind side painted cover...please check the hidden connector for tightness and place 4 zip ties on that thing to the frame.

 

Finally, this is a link to a parts finder so you can "see" .
Enter year and model.
If you run mouse over category the screen will flash with diagram.

 

IM gives good advice. I would take the battery to an auto parts store and have them load test it as well.