V-Twin Forum banner

1 - 14 of 14 Posts

·
The Best Me I Can Be
Joined
·
22,720 Posts
Discussion Starter #1
Hey y'all, need some troubleshooting help, please, on a '93 FXRT.

I realized on the way to work yesterday that I had no headlight (bright or dim) or high beam indicator. ALL other lights and indicators work.

I pulled the light from the fairing, visually checked in the fairing from front and rear. I saw no wiring damaged or loose.

I checked the white wire from the ignition switch and it has voltage when the key's on.

I have MoCo service and parts books and a Clymer service book, but very weak electrical troubleshooting skills. If you all can talk me through this, you're all on my cristmas card list.

Joe
 

·
fourty three and seven...
Joined
·
3,465 Posts
You have the bulb out?

1. You said you checked and found power to the bulb. Remember, for the circuit to work you also need a ground. check the ground.

2. check the bulb for continuity. If you do not have a meter you can use test leads or jumper wires to fake the light to the battery for testing. You can by pass the bikes positive circuit to the bulb then negative. one at a time to locate the fault.

To aid in troubleshooting, think of electricity as hot and cold water. For any electrical device to function it needs a positive and negative connection to the battery.

The wires in the circuit are like pipes for electrons to travel in. Most of the time, switches and fuses are located in the positive or hot leg.

Electrons have a negative charge and actually travel form negative to positive. For troubleshooting, look at the both positive and ground legs.

The Cat in the Hat used Calculatis elininatis to locate the missing cadenza. to locate the failure in an electrical circuit you must do the same thing. Find out what is not broken first.
 

·
fourty three and seven...
Joined
·
3,465 Posts
Forgot to mention this. It is often better to trouble shoot with a test light rather than a volt meter.

A test light draws more current than a meter. A weak connection may not show it's self to the low current draw of a meter.

A test light draws more current. First connect and look at how bright the light is on a known good circuit. Then check your head light circuit. If the bulb lights very dim....there you are, bad connection somewhere.

I have used and old alarm horn or buzzer to check circuits.

For you head light problem, in the dark garage, turn the light on and look at the bulb to see if it's dim....
 

·
The Best Me I Can Be
Joined
·
22,720 Posts
Discussion Starter #4
P 0 P E Y E said:
You have the bulb out?

1. You said you checked and found power to the bulb. Remember, for the circuit to work you also need a ground. check the ground.

2. check the bulb for continuity. If you do not have a meter you can use test leads or jumper wires to fake the light to the battery for testing. You can by pass the bikes positive circuit to the bulb then negative. one at a time to locate the fault.

To aid in troubleshooting, think of electricity as hot and cold water. For any electrical device to function it needs a positive and negative connection to the battery.

The wires in the circuit are like pipes for electrons to travel in. Most of the time, switches and fuses are located in the positive or hot leg.

Electrons have a negative charge and actually travel form negative to positive. For troubleshooting, look at the both positive and ground legs.

The Cat in the Hat used Calculatis elininatis to locate the missing cadenza. to locate the failure in an electrical circuit you must do the same thing. Find out what is not broken first.
Thanks man, but let me clarify some things though. I did NOT remove the bulb from the reflector assembly. I did NOT try for power all the way to the light.

Some one else told me to see if voltage was on white wire at key switch with key on. It was. I only looked at bulb (still mounted in reflector) for blackening or an obviously burned filament. A superficial check, I know, but my assumption was that a dead bulb would not keep the high beam indicator from working. Was I wrong?

I understand the concepts you're telling me. My trouble is in the practical application of the theory (ie, which wire is my wire, at what locations, what switches are involved to what effect, etc.)

I'll play with it after work tomorrow, and check back here to see if this clarification gives you or anyone else any ideas. I do realize that one piece of solid info ( a hot wire at the key) is damned skimpy. I was hoping that there was a common problem here.

Joe
 

·
fourty three and seven...
Joined
·
3,465 Posts
Sorry to have given an over dose of remedial electron theroy....I did not mean to underestimate your abilities in any way.

I was mis lead by one of your sentences.

I would however suggest the in the dark check. In a dark garage, turn the head light on and look to see if you have very dim filament illumination.

Knowing this forum, the right guy will post up the info of what color wire or "I had the same problem, here is what I had success with"

:cheers:
 

·
Knower of Stuff
Joined
·
1,978 Posts
Well you need to start with the simple things.
1. Is your tail light on? If not, it could be the 15 amp circuit breaker for the lights is bad.
2. Check the bulb. White is high beam and yellow is low beam, black is ground. It is an H4 halogen so do not touch the bulb, finger grease will cause it to burn out. You can verify the filiments of the bulb without removing it with a DMM.
3. Verify the headlight housing black wire is grounded. Use a DMM to measure for short from the black wire to the frame. No ground, no headlight.
4. Verify power to the headlight connector. Turn on power to the bike and measure 12 volts from the white wire to ground on high beam, 12 volts from the yellow wire to ground on low beam. If you are not getting voltage, you will have to trace the wires back to the connectors and find out wher you are loosing power.
5. The only other thing in the circuit is the high/low beam switch in the handlebar switch housing.
Good luck and I hope this helps a little.
 

·
The Best Me I Can Be
Joined
·
22,720 Posts
Discussion Starter #7
Thank you both, a bunch. I got home too late to chase any electrons tonight. I'll be checking back. And will post the answer when (if?!) I find it. And Popeye, you didn't offend me a bit. You've been my favorite cartoon character for over 40 years.

Joe
 

·
Banned
Joined
·
21,644 Posts
My guess is bulb burnt out, until I read dim and bright burnt out. Would check fuse and bulb, those are easiest. After that connections.
 

·
Knower of Stuff
Joined
·
1,978 Posts
berserker,
I could be wrong, but I do not think Harley invented the fuse untill '95. In '93, I think they were using circuit breakers for everything.:dunno:
arjonaut,
You did not say whether or not you had the service manual with the wiring diagram.
 

·
fourty three and seven...
Joined
·
3,465 Posts
arjonaut said:
Thank you both, a bunch. I got home too late to chase any electrons tonight. I'll be checking back. And will post the answer when (if?!) I find it. And Popeye, you didn't offend me a bit. You've been my favorite cartoon character for over 40 years.

Joe
I just noticed the "tool Bag" light illuminated on my dash. I went overboard spouting off electron theory for insufficient reasons.

Glad to here you did not take it as in insult. Hope you can fix the light. Because nice days pop up and the bike is already clean.
 

·
The Best Me I Can Be
Joined
·
22,720 Posts
Discussion Starter #11
((LittleBear to berserker),
I could be wrong, but I do not think Harley invented the fuse untill '95. In '93, I think they were using circuit breakers for everything.
arjonaut,
You did not say whether or not you had the service manual with the wiring diagram. )

Yeah, I've got 2 breakers- 30a (starter?) and 15a (everything else?).
I've got the factory service book, which I assume has wiring schematics. I just can't read them. Maybe I should say I've never had to try to read one....
hint to self.

Anyway, work kept me too late again today, so maybe tomorrow. Thanks again guys. Any more ideas welcome.

Joe
 

·
The Best Me I Can Be
Joined
·
22,720 Posts
Discussion Starter #12
Ok, it's fixed. My thanks to y'all for chipping in.

Don't know the terminology, so----
You've got modular plugs for quick connect/disconnect of multiple wires. Each of the wires has a metal pin type tip to lock that wire into its hole in the plug. The lock on the pin for the power wire to the headlight and high beam indicator ( one wire in, two out) broke, allowing that pin to back back out of the plug.

Simple enough, except that we had to pull the fairing. Of course, I can call it simple because I had my friend piloting the multi-meter and schematic. It was the first HD he'd ever messed with, and he done good.

It was also my first visit to his house since his wife's breast enhancement :)

Joe
 

·
The Best Me I Can Be
Joined
·
22,720 Posts
Discussion Starter #14
8-Ball said:
Now you have the makings of a truly decent thread.... not that I haven't enjoyed "the electron that could'.
Now that's effen funny.

Joe
 
1 - 14 of 14 Posts
Top