1985 500 electrical problems

Recently bought a 1985 Honda interceptor. I was told the turn signals weren’t working and the dash lights were out. I hit the horn while ridding and the turn signals started working. They work for a little while then stop and I have to hit the horn again to get them to work. Any ideas what could be causing this? And about the dash, could it be a blown fuse. Does anyone know what fuse it is? Or maybe how to replace the dash lights. Thank you for you time. I’m not really good at the electrical portion of things so i don’t know where to start. If you’re near Kansas City mo and want to come look at it too that works as well.

 

Hi Jessen and Welcome to the MadHouse

When you get time please swing by the "introductions" part of the forum and say Hi to the rest of the folks on here. They really like photos so don't be shy - tell us a bit about you and your riding history and post up a photo of your VFR - it is easy click the "up load a file" link and follow the prompts to select and upload images from your computer.

As for the electrical problems - hopefully someone more familiar with the 500 will be along with relevant advice - although the fact that several items are not working and that "impact engineering" seems to get things working for a while - it rather suggests this may be an earthing fault.

So start with the basics. Check the battery terminals are not loose, check for blown fuses, and if you are feeling brave (disconnect the battery and then follow back the turn signal wiring looking for loose earth fittings of loose connectors. If that is all good, remove and open up the left side switch gear. Ideally disconnect from the loom and dismantle indoors on a well lit kitchen table covered with a clean white cloth sheet - that way if a spring leaps out or something falls out it will not go unnoticed. Inspect and look for/clean remove corrosion/damage and loose/broken contacts. If it looks a disaster then a replacement switch may be needed.

After that you are probably into end to end continuity checks to locate an intermittent wiring fault somewhere in the loom leading to the switchgear. Inevitably 35 year old wiring may become quite brittle and break often wherever the loom flexes. Sadly intermittent wiring faults (like you appear to have) can be more difficult to locate/diagnose - so dig out the electrical schematic in the workshop manual and carefully check for uninterupted continuity on each wire whilst moving the steering from lock to lock.

As for the dash - if nothing at all is lighting up, then I would focus on common mode failure points - which means basically the connector at the back of the dash and then make sure the loom is firmly plugged in and not just located on the connector shroud! This may entail some bodywork removal for access - so be methodical - if necessary take photos as you go, and carefully label and store bolts/fittings so you will know where they need to be reinstated.

If you are really struggling with this - hopefully someone in Kansas City may be willing to swing by and offer advice/help especially if you have a well stocked beer fridge.

Good luck - let us know how you get on.



SkiMad

 

I have actually been fighting something similar where various electronics weren't working intermittently. I thought I was blowing tail lights, but the bulbs were fine... Actually just resolved what I thought was a problem with the left rear tail light this past week. I've been using this DeoxIT Contact Cleaner, 5 oz I got on Amazon that shoots a small spritz the appears to react with any corrosion on the terminals. Then I use some sandpaper or diamond grip terminal cleaner to just make sure the surface is cleaned up.

I'd recommend pulling the fuse panel cover and cleaning up all of the terminals. As a test, I put the key into my ignition and just bumped some of the fuses and was able to see different electrical components either start or stop working from minor minor inputs. They became a lot more solid after spraying with the DeoxIT (or some other contact cleaner) and using an abrasive on the mating terminal surfaces.



I'd also recommend pulling the seat up and disconnecting some of the bullet connectors for the tail/turn lights, spraying them with the contact cleaner and reconnecting them.

This would be where I start because it doesn't require any electrical knowledge. This is simply cleaning to eliminate the variable of a poor connection due to corrosion. This will make subsequent troubleshooting (if it's required) much easier.

 

To the OP - Disconnect the Battery FIRST...

 

not sure if its the same on the 500 fuse panel but in bringing my 750 back to life, I had to go through three panels before I found a serviceable one. I found that while the contacts appear to hold the fuse and look good from above (normal vantage point) they tend to break underneath and may cause an intermittent break in the connection.

not saying this is the source of your woes but pull your fuses (after battery disco of course) and check your terminals to see if you have any broken ones.

good luck man!