Headlight fuse intermittently blows

[scottolds]

Last week I was riding close to sunset and when I was behind a vehicle I noticed I was not seeing the headlight reflection, only my auxiliary lights. As it got a bit darker, I also noticed the dash lights and running lights were out.

I stopped and adjusted the auxiliary lights to shine up a bit higher and got home fine.

Checked the relays and they seemed fine. Pulled the 15 amp fuse and it was blown. Replaced the fuse and had the headlight, dash lights, and running lights back.

It worked fine for about 5 days and today I noticed the headlight, dash lights, and running lights are out again.

Looks like I will be doing some electrical troubleshooting this weekend.

Given the large number of lights affected on that circuit, are there any common areas where faults develop to check first?

This is one time I wish the fuse would blow immediately. Direct shorts are so much easier to find than intermittent ones

Thanks

Scott

[cranky]

.... you might want to check in with the VROC techtalk forum folks, lots of Voyagers there also...
Best to Ya!!!

[cushman eagle]

Check to make sure you have good connections at,and near the fuse.Poor connections can make enough heat to blow fuses.

[scottolds]

Thanks for the information.

I will definitely be checking that.

I guess the good news is I now have an excuse to pull my short circuit detector out of storage

[Lucasind]

https://www.google.ch/patents/US5942886

please give a example of the unit that you are referring to /have,

[scottolds]

The Short tester I have is an older version of this one:

https://www.amazon.com/Tool-Aid-25100-S ... B000RFLR0U

Have not used it since I had a short in my '72 Cutlass wiring harness. And I have not had that car for quite a few years

[ekap1200]

Given the large number of lights affected on that circuit, are there any common areas where faults develop to check first?


HERE IS WHERE THE MOST COMMON TROUBLE BEGINS.

Pull off your trunk/and both seats and faux tank. Where the trunk harness passes from the right side of the frame , then under the trunk frame, if not run properly it will get pinched in-between the inner wheel fender and the sharp edge of the trunk frame. Also with the seats off , make sure the harness is not getting pinched and shorting to the frame or fuel tank.
Follow that harness all the way up... Looking for the harness being miss-routed and chaffed.
And look for PO's adding EXTRA-LIGHTS to the harness and not doing a profession job of routing their wiring mess causing your issue by shorted /chaffed wires or just plain overloading the circuit. And as Loren mentioned , look at the color of the ten - pin connector from the fuse box, if its got a brown spot its been getting Hot, also look at the female spade that the fuse mates to. Is it corroded and causing heat.
( HINT ) pull the trunk first, remove the 3 plugs for the passenger radio controls and speakers, slip the plugs out of the pocket. remove the 4 fasteners from inside the trunk. Now tip the trunk forward onto the passenger seat to remove the single plug. 5min job if no PO has added wires and goodies to the trunk as extra's. Keep in mind, with a used bike you may be dealing with men that are inclined to be mechanical, but not mechanically inclined
Gene Kap

[scottolds]

Hi Gene,

Thanks for the excellent write up.

I got a little time to work on it today finally.

When checking the fuse, I was premature in saying it blew again. Turns out the second time when the lights were out was not the fuse. I probably need to find that first fuse and test it with a ohm meter since it looked ok, but changing the fuse brought the lights on. That seem to put me down the fuse blown path.

Today I just swapped around the 3 relays on the left side and got lights on again.

Then I started it and 3rd time and no lights.

Hit the starter button again and got lights.

So now it seems either my relay might be sticking or the circuit from the starter switch that switches that relay is acting up (or something else).

It actually had the same problem when I first got it and Carl swapped out the relays with some good used ones and it was fine ever since April.

Given the looks of the harness, it is entirely possible there is something else going on as well. The weather has been too nice to have the bike taken apart, so I'm going for a ride and will keep an eye on it.

Thanks again! I will be definitely going through the entire wiring harness and checking the 10 pin connector when I tackle my next project of carbs, coolant, and plug wire caps.

[cranky]

... IMHO, find the simplest, easiest failing item to troubleshoot, and work it first, I'd NOT
use the headlight, as IIRC, that gets into a working charging system and picking relays,
I'd stay away from that one....

Find the easiest wounded duck and fix that, it should get the rest.... JM2C

[VoyKimmer]

cut out the 10 pin connector and hard wire by soldering and heat shrink and all your electrical issues will go away.