Headlight will not turn on either high or low beam but if I flick the switch to high as in a passing alert , the high beam goes on but when i release, it goes off. Neither high or low work with just the ignition on. Tail light is on so there is power to the system, just not the headlight. I checked the bulb and both filaments are OK. A shop recently worked on the clutch and had to pull the engine to get at the clutch. I read on snobum's tech articles that a black wire connects at the starter relay and is a ground to the headlight relay. That wire checks good for ground. The black wire just left of the frame backbone below the tank shows a connection to ground. Any really good ideas???
Check the headlamp relay, which is one of the 2 plug-in cube relays at the rear of the electrical section, under the fuel tank. The other relay is the starter, and it will identify itself if you push the starter button. Then by elimination you have located the headlamp relay.
This is a common relay made by at least 6 companies. You can probably get an identical one off Amazon for $3, but you MUST study the schematic on the side of the relay and compare it carefully before buying. There must be 15 relays that appear to be exact replacements, until you study the schematic.
Each relay of this type carries it's schematic on the side panel....
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
I am having the same problem on my 1987 R80, but I have replaced the headlight relay twice in the past 2 months. Last night it cut out on me after about an hour of continuous use; I had installed the new one the previous night and rode it to work (10 minutes) with no issues that morning.
Your HL bulb could be the problem. It was very common in the 80's and 90's to replace the stock 65W HL bulb with 80W, 100W and even larger bulbs. Back then that was the only way to put more light on a dark nighttime road. But just because they make the bulb doesn't mean your system (especially the HL relay) can handle them.
Or, some genius may have connected extra lights (running, fog, driving, etc), grip heaters, or some other accessory which pulls its power through the HL circuit. All that extra power requirement runs through the HL relay designed for 65W.
• Pull the HL bulb and read the Wattage stamped or written on the metal rim. If it's over 65W then you're already on thin ice. Replace it with a LED H4 replacement bulb of about 2500-3000 lumens. (Look carefully at the photo of the bulb. The post the LED emitters are mounted on should be 3 or more sides. Definitely NOT flat, 2-sided.) Your typical 3000 lumen LED is generally pulling an amazingly low 20W, while also being 3 times brighter.
An example of a 3-sided LED replacement for H4
• Make sure no other accessories are wired though the HL circuit. Driving lamps, grip heaters and other accessories should be controlled by their own relay, which is connected directly to the battery through it's own fuse.
Hope this helps.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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