Ignition Problem with 1982 GS450TXZ

[DickV]

On my last ride with my 1982 GS450TXZ, the lights started to pulse brightly then all went dead including the engine. All lights that were on at the time blew including the gear indicator lamp, also the turn signal relay blew, and the engine quit. I checked and found no spark. I replaced the R/R, bulbs, and relay. When I replaced the bulbs and turn signal relay, all worked OK without having to replace the one fuse in the system. However, now I do not get spark when cranking, I get only one or two sparks when I release the start switch as the engine continues to turn for one or two revolutions. I do not have an electrcial schematic for this bike. I would appreciate suggestions for trouble shooting and I would like to know where I can obtain a good electrical schematic for this bike. Thanks.

[snark]

A good set of wiring diagrams can be found in the back of a Clymer manual. As to what caused the problem...sounds like a major short. Did you do any electrical work on it recently?

[DickV]

Respond to reply

I had not done any work on the bike before the problem happened. I assume the R/R went bad allowing high voltage output from the alternator to the electrical system. I don't know why the fuse didn't blow, however. I found the electrical schematic in the Clymer manual shows different color wires than what I have on this bike - I made sure I was looking at the schematic listed for a '82 GS450T. All connectors and wires I have checked seem to be the original harness and they appear to be in good shape, no obvious sign of overheating.

[xxwaldoxx]

Hope this helps, they are hard to read. You might be able to zoom in on them to see whats going on.

I included both diagrams because i happen to have both a clymers and a factory service manual.

Wish i could do better.

Factory Servive Manual Wire Diagram



Clymer Wire Diagram

[DickV]

Response to Walt

Walt,
Thanks for the wiring diagrams. I will print them, zoom in if possible, and if not I will get out my magnifying glass! Thanks again.
Dick

[IanFrancisco]

Since you say you getting one or two sparks after releasing the starter button I would suspect either the battery or faulty connections in the wiring harness. It's usually a good idea to go over the harness with a fine toothe comb and seriously clean all the bullet connectors and/or eliminate the key ones (charging system, coils, ignitor, etc.) by soldering the wires together. A common mod is to install a separate ground wire directly from the RR neg. to the battery neg. pole, eliminating having to rely on the harness or chassis grounds. I went one step further and tied the RR, ignitor and harness grounds to my new ground wire so all components have little or no resistance to the battery neg. pole.

I would also make sure the battery is still good and fully charged before attempting any electrical troubleshooting.

[DickV]

Reply to Ian

Ian,
Thanks for your suggestions. I will take my volt/ohm meter and start checking the wiring and ignition components as best I can. I purchased a new battery just to insure that was not the source of any problems, the old one cranked strong but was at least 3 years old. I plan to make hard grounds as you have done also. I thought perhaps the problem might be the igniter but that may just be imaging a complex problem when in fact it is simply a bad connection. I appreciate your help.
Dick

[IanFrancisco]

Another point of (dubious) interest: The coils on the GS450's don't need a good frame ground. They will fire while dismounted and dangling from their wires, getting their ground from the ignitor. BTDT. Improving the ignitor ground improved the spark on my bike.