I finally was able to put some money into a 1991 FXRS that's been sitting for a few years. I took it for its inspection today and on the way down, the tachometer was working and then the next moment, it wasn't. When the tach wasn't working, I found the left turn signal did not work either (Right worked with no issues). I really don't have the energy to sink more money into the bike as we put a lot to get it back on the road for my wife. Any thoughts or ideas as to where to look?

 

My '90 FXR has a left turn signal that comes and goes depending on the alignment of the stars and moon, etc.

Something is loose inside the headlight bucket. Miserably tight quarters in there. I just live with it.

Anyway, on yours, it's almost certainly a buggered connection or worn-through wire somewhere. Fixing it is easy. Finding it is not. Chasing electrical gremlins is the worst.

Good luck.

 

If both are going out, you need to look for a point where the wiring for both coincide at a common point. This is most likely the ground side. I'm betting you have a bad ground where the wire for the tach and turn signals are tied into a ground buss somewhere (most likely in the headlamp on your bike).

Same thing happened with my old Sporty. Drove me nuts until I got scientific with it and traced the wiring to the one common point on the ground side. I found the ground wire terminal had nearly cut through the ground wire (poor assembly at the MoCo). It was okay until I added the tach kit, which overloaded the cut wire and it started to burn.

 

Thanks for the responses. I got bored and started to take things apart. Traced everything back into the block leading into the headlight. Noticed that a couple of female pins were wider than the width of the male pins. Ran out of daylight, so will have to resume later. I personally don't care about the turn signals or the tach, but being my wife will be a new rider, I want them working for her. Now if I could figure out the fuel gauge and getting that working, I will be set. Years ago, my Dad twisted thinking it was the gas cap. Hasn't worked since.

 

Motorcycle wiring is subjected to high stresses such as vibration and constant flexing at the front end pivot point.
Your sled is 24 years old and is due for a complete electrical checkout.
Begin the process at the areas you know are under the most stress like the pivot point described . Do the stretch test i have described in this forum.
Look for any heat discoloration at the connectors and repair as needed.
Replacement connectors are available at any auto. parts shop for a fraction of the oem cost. Use only weatherproof connectors.
Get a good multimeter if you dont have one now and learn how to use it .
Plan on spending a full afternoon at this and follow your manuals instructions.
When its all done you can be happy that an electrical gremlin wont put you on the shoulder and ruin your ride.