Headlight goes out mid-ride - Ducati.ms

noyes · Nov 26th, 2011, 8:19 pm

This is something that's happened to me multiple times now. I'll be riding along and suddenly I'll notice that my headlight is extremely dim. It looks like the headlight looks when you push the starter button and it dims out. Sometimes high beam will work, sometimes not. If I turn the bike off, then back on, the headlight works fine again for the better part of the ride. I'm not really sure what is causing it to go out. I checked the connection to the back of the bulb and it's solid. I even bent the bulb terminals ever-so-slightly in hopes to make better contact.

I've been lurking this forum since April 2011, and I seem to remember reading that this might be related to the ECU (I have a stock USA ECU on 2008 GT1000), but doing a search I couldn't find the thread again. Can someone point me in the right direction or tell me if they have experienced this before and what the remedy might be? Thanks a million, Ross.

**JCPakBikes** · Nov 26th, 2011, 10:16 pm

My first thought is it is the Switch box on the handlebar
There may have been some water in there and you may have some corrosion and metal oxidization
Open up the switch box and see if it is clean and dry i there

Other wise you will need to start tracing all possible shorts or loose connections

Quote:

Originally Posted by noyes

This is something that's happened to me multiple times now. I'll be riding along and suddenly I'll notice that my headlight is extremely dim. It looks like the headlight looks when you push the starter button and it dims out. Sometimes high beam will work, sometimes not. If I turn the bike off, then back on, the headlight works fine again for the better part of the ride. I'm not really sure what is causing it to go out. I checked the connection to the back of the bulb and it's solid. I even bent the bulb terminals ever-so-slightly in hopes to make better contact.

I've been lurking this forum since April 2011, and I seem to remember reading that this might be related to the ECU (I have a stock USA ECU on 2008 GT1000), but doing a search I couldn't find the thread again. Can someone point me in the right direction or tell me if they have experienced this before and what the remedy might be? Thanks a million, Ross.

dietrichpfeifer · Nov 26th, 2011, 10:22 pm

I would definitely test the headlight relay. The wiring diagram I had did not show one at all, but sure enough there is one. Can't remember if there is one for the high beam and a separate one for the low beam, but they are the micro type relays, located under the seat. Does the high beam work and not the low beam or vice/versa? My relay went out a while ago, got a replacement at NAPA for a few bucks.

fazerian · Nov 27th, 2011, 10:18 am

I had a similar problem and it turned out to be the connector at the back of the headlight,it's pretty quick and easy to replace so might be a good place to start,Good luck!

noyes · Nov 27th, 2011, 10:23 am

Great, thanks! Checked the hand switch, clean as a whistle. Cleaned and add a bit of dielectric grease for safe measure. My instinct was there was a relay involved. My parts diagram showed two identical relays and I knew only one was required for indicators. I'm not very talented with resistance multimeter readings, so I swapped the relays and plan to take it out for a ride in a few hours. If the indicators act up and don't flash, I'll know that was the culprit.

Fazerian: I checked my connector and looked completely fine, but I didn't check continuity. What was the issue with yours? Anything to look for in-particular?

fazerian · Nov 27th, 2011, 10:38 am

Quote:

Originally Posted by noyes

Great, thanks! Checked the hand switch, clean as a whistle. Cleaned and add a bit of dielectric grease for safe measure. My instinct was there was a relay involved. My parts diagram showed two identical relays and I knew only one was required for indicators. I'm not very talented with resistance multimeter readings, so I swapped the relays and plan to take it out for a ride in a few hours. If the indicators act up and don't flash, I'll know that was the culprit.

Fazerian: I checked my connector and looked completely fine, but I didn't check continuity. What was the issue with yours? Anything to look for in-particular?

The earth post had corroded,it caused an intermittent fault, it wasn't too obvious to the naked eye.

noyes · Nov 27th, 2011, 11:15 am

Fazerian: Sorry, but this needs a bit of clarity, but thanks for the replies. You replaced the bulb or you replaced the 8" long wire connector leading from the wire harness to the back of the bulb? Either way, I'll look over this again after my ride if my problem is still there.

fazerian · Nov 27th, 2011, 11:47 am

Quote:

Originally Posted by noyes

Fazerian: Sorry, but this needs a bit of clarity, but thanks for the replies. You replaced the bulb or you replaced the 8" long wire connector leading from the wire harness to the back of the bulb? Either way, I'll look over this again after my ride if my problem is still there.

I replaced the 2 part connector on the wire that leads to the bulb,not the connector that plugs to the actual bulb.

MY 750F1 · Nov 29th, 2011, 4:14 am

I had the similar problem as you discribe, mine was the actual plug that connects to the bulb itself.

The contacts in the plug were not making a very good contact onto the bulb, they were a slightly loose fit, we are talking microns here. Usually the plug to bulb fit is tight - almost force fit if you will. mine was an easy slip-on fit.

I couldn't work it out for a while, then one day I pulled it apart again after a very long ride & discovered the plug had started to melt.
I simply cut the plug out & soldiered in a new one (any auto electrical joint will have them)....job done.

noyes · Nov 29th, 2011, 8:00 am

Glad to hear I'm not the only one that was experiencing this problem. I'll have to babysit this, but I least I know who the usual suspects are. My long ride the other day produced no problems, so I'd like to think dietrichpfeifer nailed it with the relay. I'll post again if I source a different problem.