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Topic-icon New Owner Primer: Tips to Get Your Airhead Back on the Road

3 months 2 weeks ago - 3 months 2 weeks ago #4768 by Wobbly

The OEM electrical system is a very good product, and even after decades very few items will have failed. However, it is important to note that back in the day Airheads were the kings of the road and these bikes amassed unheard of mileage in all types of weather. 40 years later, it is best to assume that prolonged exposure to water may have left some of the connections in an "iffy" or intermittent state due to formation of microscopic corrosion. There are also the Airhead quirks you want to learn about before you break down 300 miles from home. Here's some tips on the top items to check.

Owner modifications
Back in the day numerous electrical system modifications were commonly suggested to "improve the reliability". One of the common ones for the RT and RS was to move the fuses from the headlamp back to the seat area. 40 years later, the lower quality of these home remedies can end up causing electrical problems. When electrical issues arise, always view "home wiring" (if present) as the primary suspect.

Other than needing new brushes every 80,000 miles, the charging system is very reliable. Those who get into trouble have generally added too many electrical accessories. Still there is one quirk you need to know to be a successful Airhead rider... When you turn the ignition key ON, always check to insure the charge light in the gauge cluster lights up. If that incandescent bulb ever burns out, then the charging system will not operate.

• Single rear shock models... fuses are usually located in a small black box hidden above the LH side cover
• Dual rear shock models... fuses are usually located inside the headlamp shell
On most Airheads there are 2 fuses, both 8A rated, and both of the older German pointy-end style. These 2 fuses are a source of recurring trouble since they depend upon spring pressure applied by clean contacts in order to pass current. It is best to scrap the older white porcelain fuse in favor of the modern glass tube replacements. Or better yet, replace all fuse holders so that modern 10A ATM "flat pack" automotive fuses can be used. If you insist on using the older German style fuses, then you must carry your own spares.

► Most Airheads do not have a "main" system fuse, meaning... 1) not every electrical device is fuse protected (thus it is possible to burn up an expensive harness if you are not careful), and 2) if electrical accessories (grip heaters, etc) are added, each accessory will need its own fuse added on.

Voltage regulator
The OEM voltage regulator was very reliable for its day. But it's a mechanical type regulator in a sealed can, and 40 years on are showing their age. Additionally, many owners are opting for the newer sealed AGM and lithium batteries which require a slightly higher charge voltage. If you experience charging issues, then the modern adjustable, solid state regulators are the better replacement. These are available from third party Airhead suppliers.

Battery cables
Electric starter motors rely upon perfect electrical connections at both ends of both battery cables in order to be reliable. If you replace your battery, then take the time to check your battery cables.
• Negative (-) side battery cables have issues making good contact at the gearbox end. The attachment fastener is generally the hollow gearbox breather bolt which can only accept very limited torque. In order to make good contact, more fastener tightening is not an option and will not substitute for clean terminals.
• Over time, Positive (+) battery cables can wick battery acid inside the jacket and through the braid, all the way to the starter. If blue-green corrosion is observed at the starter motor terminal, then the positive battery cable must be replaced.

Replacing the OEM incandescent light bulbs over time with modern LED replacements can have multiple benefits for the Airhead owner. LED bulbs are generally much brighter, making the motorcycle more visible to other drivers (thereby increasing rider safety), and consume much less electrical power (thereby making more power available for other electrical accessories).

Also, LED bulbs are available in colors. Using red LEDs in the tail lamp and amber LEDs in the turn signals can further increase the bulb's visibility. Using softer blue or green LEDs for gauge illumination can reduce nighttime glare from the gauge set, while at the same time making the gauges easier to see.

► Airhead bulb suggestions....
• Cyron H4 style LED headlamp bulb (pn ABH4K-A6K) is an excellent bright white 2500 Lumen bulb that works well in all 12V Airhead models. At 25W it uses less than half the power of the OEM bulb while being about 3 times brighter.
• Super Bright LEDs ( ) is a great source for general vehicle replacement bulbs, including the smaller bulbs found in the Airhead gauge cluster. However, I do not recommend their headlamp bulbs.
• Remember: the alternator warning lamp in the gauge cluster must remain an incandescent bulb in order for the alternator to work.

Intermittent connections
If intermittent connections are experienced and all other avenues are exhausted, then I highly suggest the use of a product called NO-OX-ID by Sanchem. Available on Amazon, this professional electrician's paste prevents water intrusion, reverses electrical contact corrosion (oxidation), and dramatically improves electrical connections. You'll only need to apply a tiny amount (1/2 drop) to each contact, meaning the smallest package (7ml) is enough for ~10 motorcycles. I use it on both ends of the battery cables, fuse ends, relay plugs, all harness connectors, low wattage light bulbs, inside the ignition switch, horn terminals, the gauge pod connector, all the contacts inside the headlamp shell... everywhere.

Don't hide 'em, Ride 'em !!
Last edit: 3 months 2 weeks ago by Wobbly.

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