Headlight Randomly Works - Seca Turbo

I went with this title since I've had an interesting predicament with my headlight.

I was riding my bike when the blue highbeam notification on my dash went out, and lost any light from the headlight: both low and high beam. The next time I went to toy with it and everything worked fine. I rode it for a week without issue, and now the headlight went off again with the same blue high beam indicator going out.

I just took apart my headlight and replaced the bulb hoping maybe that might have been the issue, but with no luck.

Any suggestion on where I can go from here?

 

I'd start looking at the circuit wiring, the switch, and testing the relay.

Does the fault occur only when the high beam is in use?

 

Nope. Neither light, high and low beam, are working.

 

And did the meter lights go out also?

Start by looking at your fuse box for broken /corroded clips, particularly the HEAD fuse. The fuse boxes are a source of problems and many have been updated to the blade fuses.

The turbo uses the combo start switch / headlight switch in the right control. When you push the start button the normally closed contacts for the headlight open to reduce the load on the battery. I would start by inspecting those contacts / wiring and cleaning the contacts if the fuse box is ruled out.

Next on the list would be the high low indicator in the left control. The switch would need to be inspected and cleaned and is a good practice anyway with these old bikes.

Mating connections to the main harness from either the left or right control are a potential problem also. And, like the switches cleaning the electrical connections and treating to reduce future corrosion is a good practice.

The high beam indicator bulb uses the low beam filament in the headlight bulb to obtain ground. So knowing the headlight bulb is good is really good evidence that you are losing power to the headlight circuit. Also, the CMS would have set a "HEAD" warning if the headlight bulb or associated wiring out of the CMS had opened as it incorporates a filament check in the CMS.

If the meter lights did not go out some of the above might change slightly.

 

Alright. So my meter lights aren't working, but my directionals on the front of the bike are working and the Turbo's gas/battery/oil check display are working.

I also found this when I removed my battery to get a better look at my wiring connections. It looks to come through my position connection to the battery.

 

So, just to confirm. Check the starter switch on the right and make sure the connections are good, then check the light switch on the left?

 

That looks like the battery fluid level sensor, a W/R wire. If you have a wet cell battery and the sensor installed you are good to go. Otherwise, there is a way to turn that into a voltage monitor. However, first thing first is the headlight.

That comes after verifying the fuse box is OK. I am thinking the Turbo has the old style glass fuses, and the fuse box / clips presented problems like intermittent loss of power to the designated circuit.

If you get to the starter / headlight switch, you are not just checking the wires, but also the switch contact. For the headlight there is a set of normally closed contacts that open when the starter button is depressed. Those contacts may need cleaning.

Those run off the signal fuse, so not related to the headlight power.

 

Hi there again! Haven't had much time to look at the bike here is what I have to report:

I checked the fuses under the seat: all look in great condition.

I replaced the bulb to ensure it wasn't burnt. No luck.

I replaced the wiring harness that the headlight plugs into to ensure that it was corroded. No luck.

Decided to test a multimeter on the wiring harness to see if it was getting any power: I was able to read about 4 volts depending how it touched inside the harness.

Any suggestions on where I can go from here?

 

clean the headlight relay contacts and connectors
also clean high/low switch

 

Is this what the bulb plugs into directly? If so, I replaced it.

Otherwise, where would this be located? I followed the headlight wire all the way back to the dashboard but could not access where it went.

 

sorry no head light relay on turbo
in models with out relay it is common to use the starter button contact as supply to headlight
clean your starter button it should have 2 contact points.
when it was working would your head light turn on with key then go out when starter button pressed?
if so clean the starter button with electric spray cleaner and use some dielectric grease to prevent corrision

I do not have a turbo wiring diagram

check and clean lube high/low beam switch

what voltage do you get coming out of fuse on clip?

I see rooster covered this

 

Do you have an extra harness in there? Normally, the headlight plug wiring goes directly into the CMS and is the output of the headlight circuit. Or did you just replace the terminals?

If the headlight was not connected this is a normal voltage for the high beam side, the low beam terminal should read 12V as the high beam indicator bulb is seeking ground through the low beam headlight bulb filament. This is just more evidence that the power is missing, and particularly when the meter lights and high beam indicator light are not working. You are missing power, either because of the fuse or the start / headlight combo switch, or associated wiring for that.

Since you have already confirmed the fuse then checking out the starter / headlight switch in the right control is the next step. You need to confirm that you have 12V at the switch input R/Y wire into the right control and 12V out on the switch output on L/B wire. You could disassemble the right control to do this or remove the tank and verify by back probing at the right control connectors. If it is intermittent you might also find that just wiggling or tapping the starter / headlight switch will verify where the problem is.

 

Took apart the starter and noticed this bent wire going to my engine cutoff switch.

 

Yea, that looks like a poor assembly at one time or another where the wire was not routed correctly and got pinched. Look at the insulation closely to be sure there is no exposed wire. Since you were not having an issue with the bike running (cutoff or kill switch routes power to ignition) the internal stranded wire is likely OK.

If you could post a picture or two of the start / headlight switch and the right control internal arrangement for us to have as a future reference on the turbo.

 

Like this?

 

Those are good, and the one you posted in the earlier thread shows the wire side of the starter / headlight switch. So a photo of the other side of that and the switch shorting bar would be nice. That is hopefully where your problem is and where you need to clean and add some switch grease to the contacts as well as making sure the slider bar of the switch moves freely within the channel. Did you do a continuity check on the switch before disassembly to verify if it was working?

 

Added grease and put the starter back together, and the headlight is back on. Thanks!