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Airhead alternator life expectancy  

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James Bussell
(@10385)
Active Member

I was wondering...my 74 R60/6 has 84K miles on it and I believe it still has the original alternator...(I have known this bike since 1989 and I know it hasn't been changed since then)...what is the average life for the alternators on these bikes?

Quote
Posted : 10/14/2020 22:44
Richard Whatley
(@wobbly)
Member Moderator

As far as I know, most of the R bikes on the road today still have the OEM alternator. Those that do get replaced are because users either needed extra lighting (pre-LED), or wear heated vests, pants, and other winter apparel so they can ride year-round. So most of the replacements you read about are based on load requirements, not age. 

• The highest wear item by far are the 2 carbon brushes. If you have not changed these, then that is highly advisable and will set you back a whopping $6 or so. 

• The second highest wear item is the bulb behind the Alternator warning lamp on your dash/ instrument cluster. It must be an incandescent bulb and it must illuminate in order for the alternator to operate. 

• The third most common failure item is working its way up in the standings, and that's the Voltage Regulator (VR). The OEM unit worked great, but it's mechanical in nature, with swinging arms and contacts to burn out. Advanced age is simply taking its toll. All-electronic regulators (with zero moving parts) have been on the market now for 20 years. Because the Airhead VR is also common to VW, Porsche, Volvo, and 20 other automobiles with Bosch charging systems, you can now buy an all-electronic replacement starting at $12 for standard batteries. Even your local NAPA store has them. I highly suggest you replace your OEM unit as "proactive maintenance". Example

• The forth most common failure is the rectifier board. These die due to handling too much power and/or lack of air flow; in other words too much heat. Reduce the power you're using and the heat will be lowered.

 

If you want to extend the life of your alternator (and total charging system), then simply REDUCE the electrical load. Besides replacing the failure points listed above, the best thing you can do is replace your headlamp and tail lamp bulbs with LED substitutes. That will cut the power load from about 80W to well under 30W. That's a reduction of 62% (~3-1/2A less) through your rectifier, and "frees up" more power to charge your battery on short trips. (BTW, that's also a 62% reduction in rectifier board heat.)

So IMHO the alternator itself is rock solid, it's the supporting parts of the charging system that need your help. Especially at this point in their careers, when they are operating 15 years beyond their design life

 

Hope this helps.

This post was modified 6 days ago 4 times by Richard Whatley

[color=blue]Don't hide 'em, Ride 'em !!
#15150[/color]

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Posted : 10/16/2020 15:25
James Bussell
(@10385)
Active Member

Thanks heaps for the great info...I have a couple of questions...you said I needed an incandescent indicator bulb, but I recently changed my instrument board to an LED board (the kind that is advertised in our magazine) how does that affect it since I no longer have an incandescent bulb there, for the indicator still seems to be working nominally...

The only additional voltage draw are the little Wixom bag lights...that's it, in addition, I use Odyssey batteries and I try to keep it topped off with a battery tender.

Thanks for the ebay example, but I noticed it said it was 24v regulator...is that what I should be looking for?

I will be ordering brushes forthwith!

Jim

 

ReplyQuote
Posted : 10/19/2020 22:40
Richard Whatley
(@wobbly)
Member Moderator
Posted by: @10385

Thanks heaps for the great info...I have a couple of questions...you said I needed an incandescent indicator bulb, but I recently changed my instrument board to an LED board (the kind that is advertised in our magazine) how does that affect it since I no longer have an incandescent bulb there, for the indicator still seems to be working nominally...

The only additional voltage draw are the little Wixom bag lights...that's it, in addition, I use Odyssey batteries and I try to keep it topped off with a battery tender.

Thanks for the ebay example, but I noticed it said it was 24v regulator...is that what I should be looking for?

I will be ordering brushes forthwith!

Jim

 

Jim -

All good points...

• No need to worry. Your Katdash instrument board has a resistor made into the alternator warning lamp circuit that adds the required resistance. Several outlets also sell a discrete resistor you can solder into the harness in case the bulb burns out. I was discussing "completely OEM" setups.

• It's not the physical size, but rather the number of bulbs X the wattage that matters. Superbrightleds.com probably offers replacement LED bulbs for that location.

• Odyssey batteries are AGMs and require a higher charging voltage than most charging circuits and trickle chargers are set to deliver. Please read the paper that came with your battery. Therefore you'll need the higher output VR offered at http://motoelekt.com/charging.htm   

• No, my bad on the 24V VR, it needs to be 12V. I simply rushed over to Ebay and copied the link to the cheapest Bosch-type VR to make my point. But since you have an Odyssey AGM battery, you wouldn't want even the 12V version of that.

[color=blue]Don't hide 'em, Ride 'em !!
#15150[/color]

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Posted : 10/20/2020 15:14
James Bussell
(@10385)
Active Member

@wobbly Thanks once again for the awesome education! (I love learning!) I'll budget the omega system in...that way I can provision for my heated clothing on this bike also! I am going to replace the H4 with LED, as well as some of the other bulbs.

Thanks for your interest and help!

PS: My Odyssey battery is six years young, and I have no idea where the paperwork is 🙂

Jim

This post was modified 2 days ago by James Bussell
ReplyQuote
Posted : 10/20/2020 21:36
Craig Willson
(@humble-bub)
Eminent Member

Just to add to Wobbly's comment - I put the Omega system in my 91 R100RT. It has been one of my better decisions. Heated vest, heated gloves, extra lights and no fretting or obsessing over the V meter. I also changed the headlight bulb to LED and I am pleased with the improved visibility. 

Craig

ReplyQuote
Posted : 10/21/2020 05:38
Richard Whatley
(@wobbly)
Member Moderator
Posted by: @10385

@wobbly PS: My Odyssey battery is six years young, and I have no idea where the paperwork is 🙂

Jim

Then go to their web page and read. Or call and talk to them.

[color=blue]Don't hide 'em, Ride 'em !!
#15150[/color]

ReplyQuote
Posted : 10/21/2020 06:26
James Bussell
(@10385)
Active Member

@wobbly too simple...no wonder I didn't think of it... 🙂

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Posted : 10/21/2020 19:07
Chris Brackney
(@epidoc)
New Member

Which LED headlamp are folks using.

Thanks.

ReplyQuote
Posted : 10/21/2020 20:47
James Bussell
(@10385)
Active Member

@epidoc this was recommended...Superbrightleds.com

ReplyQuote
Posted : 10/21/2020 22:13

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