I have a 93 FXR, and I bought a HD engine guard mounted fog lamp kit,
the instructions say they take 9 amps of current from the electrical
system and may overload the charging system.
My question is how much "reserve" does this model have?
I want to use these as running lights and leave them on when riding
as the FXR has the small headlight and is hard for oncoming traffic to
see.
These lights have 55 watt bulbs (2) total, would smaller bulbs be an
option?
Thanks

 

I have the same (or similar 55w) lamps on my 98 Fatboy and have no problmes with them overloading the system.
Tom

 

Your year model has the 32 amp charging system, so it should never be a problem.

 

32 amp system No problemo !

 

If you want to figure out how much you're using use the simple electrical formula
amps = watts / volts/ That should give you an idea how much you're currently using. Allow some for your ignition and I'd try to stay below about 80% of current capacity just to keep your syste=m from running at full capacity all the time.

Bubba

 

I really wouldn't say never a problem. You do have a 32 amp system, however that is at 2000 to 2500 rpm. At idle, the charging output drops significantly. You may see a slight discharge at idle, especially with the brake light on. Just keep that in mind in town around stop and go traffic.

 

If you have any problems with the 55w bulbs go to 30 w.......Thats what my running lights are and i have no problems with my system,even at idle

 

Just a note on this - alternator equipped HDs use to use shunt regulators. Later models have series regulators. Having a brain fart and can't remember when the change happened. Anyway, a shunt regulated alternator puts out full power all the time; the un-needed current is shunted to ground. A series regulated alternator puts out only what current is required by the bike.