indicator lights


Information and questions on GL1000 Goldwings (1975-1979)
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Tuff77
Posts: 2
Joined: Tue Jun 18, 2013 11:10 pm
Location: Springfield, Missouri
Motorcycle: 1977 GL1000

indicator lights

Postby Tuff77 » Wed Jun 19, 2013 12:10 am



I have a 1977 GL 1000 that belong to my father. The "head" indicator light on it comes on at time and off at times. Is this light just telling me the headlight is on or is it indicating problems?



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Placerville
Posts: 423
Joined: Tue Mar 09, 2010 12:58 pm
Location: Placerville, CA
Motorcycle: 1976 Naked Yellow

Re: indicator lights

Postby Placerville » Wed Jun 19, 2013 12:11 pm

Early GL's were equipped with a RLU (Reserve lighting Unit). The RLU is located under the left-side drop-down tank panel. It's black, square, about 3"x 2" and has a black ribbon cable with a white plastic connector.

In general, the RLU's purpose is this:

If the low-beam filament of the headlight burns out, the RLU detects this fault and sends voltage to the high beam. When this happens, the 'Head' indicator lamp illuminates to warn you of this fault. Also, when your tail lights night time 'running' filament burns out, the RLU will send that voltage to the 'brake' filament so you won't be left 'in the dark' to other motorists.

To be more specific, it does this:

The Reserve Lighting Unit is designed to supply half voltage to the the high beam if the low beam fails and to supply half voltage to the brake light (bright filament of the tail light bulb) if the tail light (dim filament of same bulb) fails. If you apply the brakes while the RLU is supplying half voltage to the brake light filament, it changes to full voltage until you release the brakes. The RLU was installed in early GL's because Honda was anticipating a U.S. DOT requirement. But, it never came to be and it (the RSL) was dropped from later models.

Because your 'Head' dash light is coming on intermittently, first look at the most logical possibility of a faulty head or tail light bulb. It's easy and inexpensive to swap these out and see if the problems goes away. If it doesn't, next check your wiring connections from both of these lights. Clean and tighten all connections from the bulb sockets back to the harness. Pay particular attention to any ground wires. If your problem still exists, check and clean the connections on your RLU. If still no improvement, replace the RLU with a used one from eBay as they are no longer available from Honda. Tip: If you buy a used RLU, look carefully at the photos and/or question the seller. Many RLU's have a deformation or a 'melted' appearance to the case. This occurs when owners have run higher wattage headlights (or additional lighting off the headlight circuit) and the resulting excessive current draw results in the RLU (and your starter button switch) overheating and, ultimately, failing.
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virgilmobile
Posts: 7650
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: indicator lights

Postby virgilmobile » Wed Jun 19, 2013 2:04 pm

YES YES YES.......Clean concise,accurate and to the point....
Placerville....I'm absolutely impressed at your grasp of the function of the RLU circuit....great dissertation and diagnosis....This is a difficult function of the early bikes to comprehend and most just bypass rather than repair.....My thumbs up :D :D

Oh.....where were you when I was diagnosing a LTD fuel injection ECM module in Canada???
Well....Huh??? :roll: :roll:

Just poking...good job.

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Placerville
Posts: 423
Joined: Tue Mar 09, 2010 12:58 pm
Location: Placerville, CA
Motorcycle: 1976 Naked Yellow

Re: indicator lights

Postby Placerville » Wed Jun 19, 2013 3:48 pm

Well, thank you, Virgil. I got a 'forced education' on the 'overheating RLU and starter button switch' when both of mine started going south. I got rid of my high-wattage headlight, found a NOS RLU on David Silver Spares and rebuilt/repaired my starter button. No more problems. Well, that is, until my 8-pin rectifier plug burnt up and I learned that you actually need to solder those pins to the connecters to make a good connection. THEN, I had no more problems. :roll:
Placerville- 1976 Yellow
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virgilmobile
Posts: 7650
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: indicator lights

Postby virgilmobile » Wed Jun 19, 2013 4:24 pm

Welcome.. :ugeek: ..Solder the 3 yellow stator wires too...Did you know that the 2 piece charging system can be replaced by one from any vintage up to 87.???They just combined the rectifier and regulator into one box....Easy peasy.. :) :)

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Placerville
Posts: 423
Joined: Tue Mar 09, 2010 12:58 pm
Location: Placerville, CA
Motorcycle: 1976 Naked Yellow

Re: indicator lights

Postby Placerville » Wed Jun 19, 2013 4:32 pm

Good information. Thanks!
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Tuff77
Posts: 2
Joined: Tue Jun 18, 2013 11:10 pm
Location: Springfield, Missouri
Motorcycle: 1977 GL1000

Re: indicator lights

Postby Tuff77 » Wed Jun 19, 2013 6:03 pm

Thank you very much. I had thought it might be a burnt light but all was working. For sure didn't know about the back up system. Thank You again and I will replace the bulbs and try that.

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Fred Camper
Posts: 1152
Joined: Sun Aug 16, 2009 9:15 pm
Location: Metro Detroit, MI
Motorcycle: 1977 GL1000, 1976 LTD GL1000

Re: indicator lights

Postby Fred Camper » Wed Jun 19, 2013 9:17 pm

I replaced my regulator and rectifier just as Virgil mentions with a nice MOFSET unit from a mid 1990'a CBR600RR. About the same stator output and more efficient. Nice to have a nice solid 14.3 volts at idle now when all is hot or cold.




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