odd sudden electrical issue 1982 850L

[Anonymous]

Hello all,

This forum is amazing.. Seriously, you guys are great.
So here's a question for you:
I have a 1982 GS850L, I bought it in 2000 when it had 35K miles and I've ridden it as main transportation every year since I've had it. (well, in the warmer months at least... minnesota and motorcycles don't always mix in January) It now has 51K miles on it. From all the forum posts and FAQ's, I think I may replace the R/R (I've had charging issues before, when the wires out of the stator melted together..) and my battery is just 2 years old, but seems to lose it's charge after a couple weeks of riding.

ANYWAY. I just replaced a broken choke cable a couple days ago, and the day after doing so, my headlight, signal lights and tail light(running, not brake) all of a sudden stopped working. The Gear and Neutral lights still work, as does the horn, brake light, and electric start.
Fuses are all fine, and it starts and runs fine.

So I got out the voltmeter and started testing..
The brown wire that runs from the ignition switch to the tail light wasn't giving any voltage with the ignition on..(well, it said 2v at one point, but I think that was a mistake..) So I tested the continuity from the switch to the back of the bike, and it was good.. also tested random wires from the headlight rats nest to the fuses/signals/voltage regulator etc.. all seem to be fine..
Could there still be a short, even if the fuses aren't blowing? Could this be related to a bad R/R? or do I have to bite the bullet and tear apart the whole wiring harness?

Thanks in advance for any advice you can offer..

Adam
minnneapolis

[Anonymous]

Hi, I have a 83 GS850L and I had so many "gizmo" last summer on my motorcycle, that I had remake each connection and inspected each welded splice and each inch of the insulation on all the harness. What I found is that most of the problem did come from bad connection and corrosion in the connector. But did you disconnect all your wire before doing your continuity test and did you have the wiring diagram? I have them...

[Anonymous]

thanks for the fast reply.. yes, I disconnected the wires before testing them, but I didn't test all of them yet.. I also did some testing between wires and ground, and a few seemed like they were shorting to ground.. ohm meter should read infinity between headlight hot and ground, right? well I'm getting like 4 ohms or so.. similar for a couple other wires.

and yes, I have the clymer manual and it has the diagram in the back..

I'm dreading it, but I think I'm just going to have to tear the whole thing apart to find the problem

[Anonymous]

as per mystere, check all connectors first. Are all of the functions giving trouble on the same fuse? Check the fuse with a meter as well as with the eye. Use your nose on the loom as well if you are suspicious of a certain spot, sounds odd but hot electrical equipment especially if it is in distress gives off a very distinctive odour. Do you have a wiring diagram?
If so, you shouldnt have to rip and tear until such time as you have established that electricity is present at one end of a wire and not at the other. Sometimes it is a good idea to do the tests on the volt setting instead of an ohm setting as a bad connection is often good enough to give a signal to an ohmeter but breaks down under load so use your trickle charger to help the battery out and load the circuits up for a real life look at the system. Assuming all the connectors are proven good, start from the fuse box if the problems are all on one fuse circuit and logically move down stream. Look for the point in the diagram that all the problems have in common and pay attention when you get there. Clamp one of your test leads to ground so that you only have one lead to deal with (if you are using the volt system) and away you go.

[Anonymous]

I forgot to tell you a little trick when searching for grounded wire and testing continuity...
1-ALWAYS FOLLOW THE KISS RULE! (Keep It Simple & Stupid)
Problem source is rarely complicated, why trying to analyse electron flowpath in a wire to finally find that the bulb is simply burn! (after a week of work!)

2-Found the GOOD wiring diagram for YOUR bike!

3-Diconnect all terminal that join to the wire you are testing

4-Before guessing on wire problem or electronic unit, take a close look to your connector, make sure they fit snugly, corrosion free and cleen.

5-Never search without a plan of battle. Take note of all data.

6-If you have many problem, most of the time many came from the same source, so try to check what is commun to all problematic system.

7- Faulty wire to ground path: Connect one terminal of your tester to the frame (be sure to have a good connection) and connect the other terminal of your tester to one end of the harness. Then if you have continuity, you have a problem, if not move your harness on the bike to find possible intermittent ground path. If you have no continuity at anytime, you probably don't have problem from that.

8-Broken wire : test the continuity from each end to all poosible end of the tested wire. The resistance should be very low , about 0,5 ohms or less (normaly around 0,2 ohms). If you have continuity at all time, retry while you move your harness on the bike to find possible slightly broken wire. You should not have any variation in resistance. Take a closer look at terminal connector, harness attachement and where you may get some water trap with your wire.

Good luck!

[Anonymous]

thanks for the advice.. I'll tackle it tomorrow and bug you all with more questions!