TS90 Electrical Problems

[smokingbanana90]

I am having problems with my electrics on my ts90. The bike runs but nothing electrical works. Would the rectifier have anything to do with this or the ignition switch? I've tested my headlight and horn with a 6 volt battery and they both work fine. I also cleaned all the grounds and all my wires are good. Does anyone have an idea of what it could be? Thanks!

[jabcb]

What year is your TS90? Do you have a wiring diagram?

Does the alternator keep the battery charged up?

Your bike may have a magneto ignition or PEI. If it does, then the ignition system is completely separate for the electrical system.

[smokingbanana90]

It's a '72 and I do have a wiring diagram. The alternator does charge the battery. The bike has a magneto flywheel ignition. The ignition switch has two positions, 1 for running, 2 for lights and running. The only component that works on the bike is the horn and it should work on both ignition switch modes, but it only works on lights mode. Is there a way to test the magneto? Thanks!

[jabcb]

Would help if you could post a scan of the wiring diagram.

[smokingbanana90]

This is the only one I have. It's kind of hard to read.

[jabcb]

A somewhat better copy of the wiring diagram is here: http://smokeriders.com/Technical/wiring ... grams.html

What is the history of the bike? Did you just get it? Or have you had it for a while with these problems being new issues?

The little chart in the lower right corner of the diagram shows how the ignition switch is wired up.
The diagram shows 9 wires. Also shows 4 key positions: off, on, on with lights, and parking with taillight on.

Does your ignition switch have 9 wires going to a single electrical connector? Does it have 4 key positions?

Do you have a multimeter?

[smokingbanana90]

This bike used to be a pit bike and someone messed with the electrical system. I got the bike about a year ago, got it running last July and it had this issue. I decided to restore it and while it is apart I thought I would fix the electrics.

The switch has 9 wires to a single connector and 3 positions.
I do have a multimeter.

[jabcb]

Suzuki had several different wiring layouts around 1970. (This is based on the T-series bikes -- I don't know much about the TS-series.)

Early model year wiring layouts had a 4 position ignition switch: off, on, on with lights, & parking with taillight
The left handlebar switches were: horn, H/L headlight, and possibly L/R turn signals.

Later model year wiring layouts had a 3 position ignition switch: off, on, & parking with taillight
The left handlebar switches were: lights on/off, horn, H/L headlight, and possibly L/R turn signals.

Don't know when Suzuki made the design updates to the TS90.
The TS90 wiring diagram is for an early model year wiring layout without turn signals.

What left handlebar switches does your bike have? Does it have lights on/off? Does it have L/R turn signals?

You may have an early model year wiring layout that does NOT have a lights on/off switch on the left handlebar.
The PO may have replaced the ignition switch with a 3 position switch.
This would result in you having no way to turn the lights on & off.

[smokingbanana90]

The left handlebar switch has high/low beam switch and the horn button. The other side has l/r turn signals. I have a 72 TC90 which has the same switches on the handlebars and the same ignition switch.

[jabcb]

Ignoring the 3 vs. 4 position switch problem, the TS90 wiring diagram doesn't look 100% correct.

The TS125 wiring diagram has a 3 position switch: http://smokeriders.com/diagrams/Suzuki/ ... schemw.gif
It may provide some insight into what your TS90 actually has.

How many wires lead to the magneto + neutral switch?
One wire is for neutral. One wire is for the magneto. Do 2 or 3 wires go to the alternator?

Would be useful to create the ignition switch circuit chart for your ignition switch. (Its the diagram in lower right corner of the wiring diagram.)

Your chart would have:
1) vertical axis:

• off
  I
  II

2) horizontal axis

• ignition switch ground
  B/W - battery +
  B/Y - magneto connection (grounds magneto to stop bike from running)
  R - hot / battery -
  O - hot when key is in on position (on, on with lights)
  G/W - alternator AC for daylight coil
  W/R - alternator AC connection to rectifier
  Y/W - alternator AC for lighting coil
  GR - lights
  BR - lights

[smokingbanana90]

There are 5 leading to the magneto/neutral switch and 3 go to the alternator.

[jabcb]

Looks like your magneto & ignition switch are wired up as shown in the TS185 wiring diagram.

To confirm this it would be useful to create the ignition switch circuit chart for your ignition switch.
Your chart would have:
1) vertical axis:

• off
  I
  II

2) horizontal axis

• ignition switch ground
  B/Y - magneto connection (grounds magneto to stop bike from running)
  R - hot / battery +
  O - hot when key is in on position (on, on with lights)
  BR - tail light
  LG/W - alternator AC for daylight coil
  R/W - alternator AC connection to rectifier
  W/Y - alternator AC for lighting coil
  R/Y - 2nd alternator AC for lighting coil
  ? - headlight (can't read the color off of the wiring diagram

Check to see that the wire colors for the ignition switch match up to the colors in the wiring harness.

P.S. Had a typo in the list for the TS90 wiring diagram. Should be "B/W - battery -" and "R - hot / battery +".

[smokingbanana90]

I made a chart and the wires are the same.

[smokingbanana90]

I put some new light bulbs in my speedometer and I started it up and they worked for a couple minutes and then the bulbs died. Is that because the headlight isn't working? Is it possible to have too many grounds?

[jabcb]

Does you chart match the one in the TS125 wiring diagram?

Interesting wiring layout in the TS125 wiring diagram.
Headlight & speedo light are powered by AC & are on only when the alternator produces AC.
Tail/stop light & neutral light are powered by DC.

Your bike does not have a voltage regulator.
The load & alternator output are balanced so that it can rely on the battery as a voltage regulator.
Since it has a magneto, the ignition system is not part of the load.
The headlight is a large percentage of the total load.

Without a working headlight, the load is much smaller, which results in higher voltages.
Not familiar with your bike, but I am not surprised that the speedo bulb burns out if you have no headlight.

A bad battery can also result in higher voltages.
You bike will run without a battery, but doing so will burn out bulbs.

Is you tail light working? its part of the load.

You can't have too many grounds.