Electrical problem on Evo FXR ?

[ElekVins]

I recently put back on a road a 1990 FXRS which have been sitting for a long time.

I rode it several times on short distances, after some dialing it ran ok for about 200 miles.

The other day I was riding it at about 60miles/hours when engine suddently died.

Nothing weird before.

On the side of the road, I try to start it again, the starter doesn't even make a noise.
I lost everything electrical, except for the rear light.
I tought of a loose ground, but the ground wire is still bolted firmly to the primary case.
Battery is near 13V
I tested the relays and they all seem to work fine.

Any idea?
Where should I look next?

[JBinNC]

The electrical system is divided into three parts by the breakers, main serves all, but the three are ignition, lightning, and accessories. Find those breakers and start there.

Jim

[ElekVins]

They look like this, stock wiring I believe.
I've tested them with a continuity tester and they seems to be all closed.
Should I change them all?

[confab]

Do you have a manual? You can probably download one from the Carl Salter website.

Use the wiring diagram and run down your problem with a test light.

It's probably something stupid and simple, and finding it is the hard part.

[JBinNC]

They look like this, stock wiring I believe.
I've tested them with a continuity tester and they seems to be all closed.
Should I change them all?

I did not mean replace them. I meant that the breakers are the point to begin your diagnosis. For instance, the ignition and start button are served by the ignition breaker, so with a no-start condition, begin there and follow the voltage.

Jim

[markwade74]

Starter relay is my bet

[ElekVins]

The original one was dead so I replaced it with a new one couple month ago.
That wouldn't explain why the engine died at speed neither

[ElekVins]

I replaced the main breaker and the cable connecting it to the positive of the battery.
No improvement, still no starter, no ignition, no front light.
Ground is good, anywhere on the engine.
Battery still at nearly 13volts

Any idea where I should look next?

[jadewarm]

I replaced the ignition switch where the key goes in on the dash of my 1990 Fatboy. Got going down the road and it died suddenly. No lights or starter or anything. Since I knew what I had just messed with, I took my dash off to look on there. One of the three wires off the key had touched the metal of the dash and shorted out. Super simple but maybe you could check in there. Or in your switch housing on your handlebars, I've seen those vibrate onto metal and short out before too.

[ElekVins]

ok, will look at this but when I turn the key the rear light goes on...

[ElekVins]

Does anyone knows the function of the "electronic module" ?
I guess it controls the ignition...
If broken, could it be the reason for no starter too?
I guess no, but could be wrong

[JBinNC]

The "electronic module " in your diagram is the ignition module. If it is defective, of course the motor might not start, or if it does start, might not run well. But a bad module does not prevent the starter from turning the motor over when the start button is pushed.

You need to use a test light, like confab said above, and using the wiring diagram, follow the voltage and see where you have a disconnect. Could be a broken wire or a bad switch, etc. It's an old bike, and vibration, weather, and wear and tear take their toll.

Be systematic in your diagnosis. You can even draw the ignition and starting circuits from the diagram, leaving out the other circuits to make your own diagram that might be easier to follow.

Jim

[farmall]

Probe with an incandescent test light everywhere power should be and is until you find where it should be and is not.

FXRs are quite simple but you need to visualize each SUB-system as Jim suggests above. Breakers protect wiring. They are thermal so they reset when power is removed.

Probe for power. Then if that suggests continuity is interrupting power address that, but most of your task can be done with a test light.

I'd probe the key switch at each position. I get about ten years out of Drag Specialties cheapies. You can bypass the switch if you like. Starting control and ignition power can be followed from the key switch but not getting power to the headlight suggests the lighting breaker is not getting power either and the key switch controls that.

Since you must expose the ignition switch terminals to probe them you can also:
Bypass desired switch postitions with a jumper, but that doesn't address a short to ground within the switch.
Disconnect the switch then make the connections with jumpers.

[Hoghead]

Does anyone knows the function of the "electronic module" ?
I guess it controls the ignition...
If broken, could it be the reason for no starter too?
I guess no, but could be wrong

If you decide it is the electronic module let me know, I may have a spare.

[confab]

Start at the battery and run down something simple, like the front light..

Test for power along the diagram from the battery till you find the problem and when you find it, you'll probably fix all your problems in one move.

I can't see the wire colors on your chart because it is so small. The locations in the connectors are marked also. (And connectors are a good place for BS to happen) But they're all marked there and you take your light and follow the power through the bike.

The colors are marked like: "B" or "BL" = Blue. BR = Brown. Etc..

And it is probably something stupid simple.. It's just a matter of running it down.

If you find corrosion in any connector, clean it up either mechanically or with some contact spray and get some OxGuard from your local hardware store and put in there to stop it from happening again.