Ignition Help

[spayne83]

I've put the bike back together, but still no start.

So following the TCI repair thread (http://www.xs11.com/forum/showthread...t+spark&page=3), I checked the voltage at the TCI and on the R/W wire I get a steady 12.5V with the ignition on. At the R/Y wire I get 11-10.5V (never less than 10.5) when cranking. Between the B and Orange wires I get .53V when I turn the switch to run and also when cranking and it quickly drops to 0. Same with the B and Gray wires. The resistance between Gray and Orange Wires is 6 ohms measured at the connection to the coils. I used a spark checker and the coils are not firing on either #1 nor #2 so I would assume there is no spark on 3 and 4 either.

Brand new coils, and wires, and I checked the connections at the TCI and used DeOxit on all of them. I also sweated all of the connections on the TCI board. I can't figure out why I am not getting the 10-11V at the gray and orange connectors. Does that mean that my TCI is bad?

[BA80]

Have you tried bypassing the ballast resistor?

Are you sure all your wiring is correct. At cranking the coils should be getting full voltage and bypass the ballast resistor.

Check the diagrams in the manual and make sure all is hooked up right.

[oldyam80sg]

I did have a TCI go bad-Randy(don't know his screen name )confirmed it with a test and had to get another one he had sold me.I also bought another as a spare.

[spayne83]

The ballast resistor was cut out, but I neglected to connect the W/R and the R/W. Now it is firing, but it is backfiring out the carbs. So that is one less thing to worry about. Thanks for the help.

[BA80]

Now it is firing, but it is backfiring out the carbs.

Be sure you don't have the coils hooked up wrong. Primary or secondary.

It could be firing the wrong cylinders at the wrong time.

[spayne83]

It lives!!! You guys are the best.

It was the coil wires, and now it runs just fine(ish).

One final question. Why would the tan wire coming from the key switch get hot? Is that normal? It is getting too hot to touch and that has me worried since the plug was melted before by the PO.

[BA80]

The tan wire from the ignition switch goes to the generator. Check your wiring there. It's probably just a bad connection at a plug but make sure everything is where it's supposed to be and not grounded somehow. Wiring wise that is.

You might test the windings in the alternator also. If it's been an ongoing problem there might be a shorted wire in the stator.

Is the tach working right?

[CaptonZap]

One final question. Why would the tan wire coming from the key switch get hot? Is that normal? It is getting too hot to touch and that has me worried since the plug was melted before by the PO.

The tan wire carries all the current to three of the fuses in the fuse box, and if it is gatting hot, you have a short or semi-short someplace in the wiring of the headlights, sidnal, or ignition circuits.
Start by pulling one fuse, and see if the wire does not get hot. Go to the next fuse. You can locate the fault that way.

CZ

[crazy steve]

The problem could also be just a poor connection; make sure the connection to the switch is good, also that the fuse connections in the panel are tight.

One other thing to check is the alternator field coil; that tan wire is also the power to the coil.

[spayne83]

There is 2.5 ohms of continuity between the tan wire at the switch and the ground with the power off, so I assume that something is grounding out in the wiring harness.

[BA80]

There are 2 harnesses that plug in near the fuse box that come from the alternator. A large one with 3 white wires and a smaller one with the tan and a dark green wire. Unplug them one at a time and see if the short goes away.

If it does check the field coils for short to ground.
Let us know what you find.

You never did say if your tach was working right or not. It runs off pulses from the alternator so if there is a charging system problem it usually shows up with no or unusual tach operation.

[spayne83]

No tach yet, but I have one in the mail.

Unhooking those two did not change the continuity.

[spayne83]

So it was actually 2.7 k ohms at the tan wire at the switch. I just checked the other tan wires that go to the front of the bike and those read 340 k ohms. I've removed the fuses and the readings stayed the same, but I tried testing putting the fuses back in and the 20A fuse (which is linked tan to tan) caused the other wires to read the same as the switch. So, if I am reading the wiring diagram correctly, the ground is somewhere between the switch, the rectifier, the generator and the fuse box.

[BA80]

No tach yet, but I have one in the mail.

Unhooking those two did not change the continuity.

OK. Are you checking the harness with the ignition switch unplugged or plugged in? Just to be certain the short isn't in the swtch itself is why I ask. Also, that tan wire supplies power to 3 of the 4 fuses. You should be able to see which 3. Pull those 3 fuses one at a time and see if the short disappears with one of those.

Do you have a manual w/ wiring diagram?





AHHHHHHH NEVERMIND.You posted while I was hunting and pecking.

[spayne83]

I am testing with the switch unplugged. So removing the rectifier changed the reading to 6.8 k ohms. I tried the generator connections again and now change, so that means that somewhere I spliced in a wire that I shouldn't have. But what does that change after unhooking the rectifier mean? Is the rectifier bad?

Just to make sure, there should be no continuity between the tan wire and the ground, with the power off, correct?

Yes, I have the clymer manual, as well as a 79 SF wiring diagram that was posted here.