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Turn signals and voltage meter question

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John Young
(@john-young)
Eminent Member

 Hello, 

New member to the ABC. Request to post. I have a new to me 1985 r80rt. It's a great bike that I purchased from another member. Wanted to request permission to post, so my question is, when I engage the turn signal is it common for the voltage meter? needle to move a bit in unison with the turn signal?   Thanks.

 

Quote
Topic starter Posted : 07/07/2021 13:49
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Scot Marburger
(@8166)
Member Moderator

Hello John, welcome to the ABC!

The turn signal bulbs I believe draw 7 Watts of power, or a little more than 2 amps. That's probably enough to make your volt meter jump a tiny bit, especially if the engine isn't running. I'd check on my RT, but I've substituted LED "bulbs" that draw considerably less current, and I don't recall seeing any bounce at all.

Dirty contacts at the turn signal relay or lamp sockets will also cause problems, and in a new-to-you bike one of the jobs you should consider is cleaning all the electrical contacts, not just those associated with the turn signals. With almost 40 years of use, they're all bound to be dirty, and could use a little help. I use and recommend DeOxIt cleaner and diamond tipped contact cleaning tools. Mac sells a set that I've found to be really handy, and you can get DeOxIt through Amazon.

Congrats on your RT purchase, and I hope you have fun with it!

 

Scot

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Posted : 07/07/2021 14:01
John Young
(@john-young)
Eminent Member

 Thank you Scot! Great advice. A new turn signal relay is on it's way. It was making an odd noise when the left signal was blinking. Gonna go thru the electric contents next. Appreciate you.

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Topic starter Posted : 07/07/2021 18:12
Richard Whatley
(@wobbly)
Member Moderator
Posted by: @john-young

It was making an odd noise when the left signal was blinking. Gonna go thru the electric contents next. Appreciate you.

Welcome Aboard !

The same flasher circuit is used whether you signal Left or Right. 

 

You can see from the schematic that the power gets sent through the flasher unit before going to the direction switch. I'm not doubting you, I simply think it may be something else.

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

ReplyQuote
Posted : 07/08/2021 16:02
John Young
(@john-young)
Eminent Member

@wobbly Do you think that it might be the bulb and socket connections that may be a bit dirty? I've ordered some deoxit to go thru my electric contacts. I don't have the ability to read a multimeter otherwise I could narrow things down. Thank you for responding.

ReplyQuote
Topic starter Posted : 07/08/2021 19:23
John Young
(@john-young)
Eminent Member

 Update: put in a new relay and it isn't making an odd noise when I switch on the turn signals. Left one in particular but the volt meter needle still moves in unison with the signal. 

 On a side note, the bikes that I've had in the last 10 years are an 1150gs and a k75. although both are great bikes. Hard to explain but I fit in and on the 1985 r80rt better and just feels great riding it. 

ReplyQuote
Topic starter Posted : 07/08/2021 19:37
Richard Whatley
(@wobbly)
Member Moderator
Posted by: @john-young

@wobbly Do you think that it might be the bulb and socket connections that may be a bit dirty? I've ordered some deoxit to go thru my electric contacts. I don't have the ability to read a multimeter otherwise I could narrow things down. Thank you for responding.

Before I answer that very good question, let me ask one of my own... How many 1985 cars did you see on the road yesterday ? If you said "none" or "one", then there's a very good reason for that. 1985, as far as road-worthy machinery is involved, is ancient history. I go to "classic car shows" and people drive to those shows in 1985 cars! 

This points to a common issue. In our heads, we think of ourselves as being age 25-30, only this time around with a lot more common sense and money. 😆 

That makes our Airhead (mentally) only 3 or 4 years old. But the truth is your bike (which is one of the younger Airheads) is actually 36 years! Most of the bikes in this Club are past 40, some nearing 50. What I'm leading to is that these bikes have now reached official Vintage and Classic status. That doesn't mean we shouldn't ride them, we should. What it does mean is that we need to maintain them with a WHOLE new mindset. In short, maintenance needs to be taken to a whole new level. Maintenance needs to become more proactive

One of those areas is in the electrical system. Whether or not your bike was ever ridden cross-country to a national convention in 3 days of pouring rain or not, I bet you'll agree that in the last 36 years, it's enjoyed it's share of afternoon wash-downs. Now you'll also agree that water is water, whether it comes from a cloud, a car wash, or a driveway garden hose. And it should come as no surprise when I tell you that water is the number one oxidizing agent, and that oxidation of electrical contacts is the number 1 issue with all older electrical systems. 

Now back to your original question: Do I think the bulb and socket could be suffering from oxidation in the bulb socket. My truthful answer would be: I think after 36 years that every connection on the entire bike is suffering from some level of oxidation. You are lucky that it may have started in one of the turn signals, and not the ignition system when you were 300 miles from home.

You are also very smart in that you are "listening" to your bike. This is the way vintage and classic bikes talk to their owners. If you follow through on this "signal" from your bike, then you will dramatically decrease the chance of ever being left on the side of the road by a lighting failure, charging failure, or ignition failure. The cure, as mentioned above, is to treat each electrical connection with an electrical anti-oxidation compound. And when I say "connection" I mean any place wire plugs to wire, relay plugs into socket, fuse contacts fuse holder, harness plugs to harness, or bulb plugs to bulb socket. 

I use a product called No-Ox-Id by Sanchem (also found on Amazon), but it is the equivalent of the product previously mentioned. This class of compound works to stop old corrosion and at the same time prevent any new corrosion. So it's a "double whammy". The amount you need on any single connection is miniscule, certainly no more than the equivalent of 1 drop of water. And you don't need to treat the entire bike in a single marathon session. You can do the turn signal pods and tail lamp on day one. You can then do your under-seat fuses, battery cable connections, and harness connections on another. Then move on to your under-tank connections. All your bike is asking for is: a plan. The work is as simple as unplug a single wire, treat the male gender connector prong, and plug the terminal or connector back together. 

From then on, whenever you have the Starter Cover removed, treat all the connections you see. Whenever you have the Front Engine Cover off, treat all the connections you see. Simply include these areas with your regular maintenance and you'll be fine, just don't allow an opportunity to treat a new connector pass.

Hope this helps.

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

ReplyQuote
Posted : 07/09/2021 05:48
andy murphy
(@murphyam53)
Eminent Member

John,

All the advice and information from Mr. Marburger and Mr.Whatley is absolutely correct and to the point. I think I can add a few specifics. I am the proud owner of a 1995 R100RT that is very close to the same bike with some wiring differences. My bike's voltmeter would also wiggle with the turn signals and droop when I turned on the grip heaters. This is caused by dirty connections between the battery and the largest electrical loads on the bike: ignition, lights, turn signals, brake lights. The power to these loads is controlled by the ignition switch, light switch, brake light switches, turn signal relay, and kill switch. All of this wiring comes together on the interconnect circuit board in the headlight shell. Ideally all of these connections should be disconnected (one at a time), cleaned, tightened, treated with no-ox-id, and reconnected. Also clean and treat the two fuses on the interconnect board. The schematic on your bike shows a single wire connection at the ignition switch that also needs cleaning and treating. The switches could also use a good cleaning, but don't try to disassemble these. De-ox-it (different company, Craig Labotatories, D-series) makes a spray cleaner that also lubricates the switch mechanism. 

This process should ideally also include all electrical contacts: relays, lamp sockets and lamp bodies, wiring interconnections, charging and ignition connections. I know that sounds like a lot of work, and it is, but it will solve electrical problems that you haven't even seen or found yet.

The experts and well seasoned enthusiasts on this site are here to help you keep that fine old BMW reliable and entertaining for many years to come.

Andy

1995 R100RT

ABC# 15601

  

ReplyQuote
Posted : 07/10/2021 13:25
John Young
(@john-young)
Eminent Member

   Scot, Richard and Andy, Thank you very much for your help. I am going to follow your directions and really do a good electrical connection cleanup.  With some of the harness? connections is there any that might be a challenge for the novice to get apart? Along the way I would like to upgrade as many light bulbs to leds. Scot you mentioned that you changed your turn signals bulbs to led type. In another post also Richard you recommended a headlight led bulb on Amazon. I looked it up on Amazon and it is not currently available with no eta. I'm a bit out of my knowledge base on bulbs. Can you recommend another option that is a good fit? Not sure if there is a complete package that a vendor might sale that has all these bulbs. If anyone has other suggestions in this cleanup I would be greateful. Andy, can you tell me if you know what changes BMW made between 1985 and 1995 RTs? I'm in Savannah, GA. and have been reading about tech days and other outings regarding the Airhead Community. Looking forward to getting my bikes electrical cleaned up and plan a road trip to meet up with others from the ABC. That first round of drinks will be on me. Thank you again for the time you took to get back with me.  

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Topic starter Posted : 07/10/2021 15:44
Richard Whatley
(@wobbly)
Member Moderator

John -

I'm not any type of authority on the R80 wiring, so forgive me in advance if I error. Most of the interconnect wiring is either inside the headlamp or under the tank, but your actions will be the same for either design. But I believe the bulk of your connections are inside the headlamp shell (PLEASE TELL ME). Here's a compilation...

  • The anti-oxidation treatment will go as previously described. The only mishaps will be if you plug the wire back onto the wrong terminal, so I suggest you work with a bright white work light to make the colors stand out. And unplugging one wire at a time will vastly increase your chances of success. A pair of flat-nosed pliers called "duck bill pliers" will also make things easier. Unplug, swab the male terminal with a ear swab coated in compound, and re-connect. Occasionally you will feel a loose connection and you can tighten those up with your pliers, but most of the connectors have not have been disturbed since Munich and be "Das ist gut".
  • Same goes for any relays inside the headlamp shell. 
  • The one area for vast improvement is the German cone-end fuses. They were only passable when new. A huge step forward is to adapt modern 7A mini blade flat-pack fuses, which requires new fuse holders. I use the "hood-less" type holders since the headlamp shell provides weather protection.

  • Your LED lamp conversion will only be worthwhile if you fit bulbs that match the color of the lens. For example, the turn signal lens are Yellow, so you should order 4 Amber turn signal bulbs. The tail lamp is Red, so use Red LED bulbs there. I get my bulbs from Super Bright LEDs.... all except the headlamp bulb
  • For an H4 replacement HL bulb you are looking for a construction that places the elements on a 3-sided column. Such as this one. If you go back to the previous source, you'll see that all their bulbs are constructed on a flat (2-sided) substrate. A 3-sided construction more fully illuminates the HL reflector and thus 1) more fully illuminates the road, and 2) makes you MORE visible to on-coming traffic. Once you stop to think about it, the reasons and advantages are intuitive.
  • One additional advantage you can give yourself is to replace the OEM mechanical voltage regulator with a modern solid state version. You can get these at the bottom of the page here: http://motoelekt.com/charging.htm   Most of the people replacing their alternators simply need a new regulator, so you can save yourself $400 right there. (And, you can share half your savings with yours truly. 🤣 )

Hope this helps.

 

PS. My only additional concern is if you have the front brake master cylinder under the tank. Those model year bikes are a special case and require EXTRA work to clear the wiring of the brake fluid that has undoubtedly spoiled some very important electrical connections. 

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

ReplyQuote
Posted : 07/11/2021 05:48
David Elkow
(@4949)
Estimable Member

Just tossing this in.  Based on a previous ABC forum discussion, I believe that LED bulbs can not be used for the turn signals on ‘81-‘95 models due to the way the circuit is wired. There might be a work-around for this … don’t know. 

ReplyQuote
Posted : 07/11/2021 18:29
Richard Whatley
(@wobbly)
Member Moderator

Oh sure, David ! Just "toss that in" and ruin everyone's fun. 🤣 

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

ReplyQuote
Posted : 07/12/2021 06:54
John Young
(@john-young)
Eminent Member

  I found out as well that my 85 r80rt won't take leds in the turn signals. So update on my slow progress: I got the deoxit today. I was in the process of changing my final drive and driveshaft gear oil. I was confused by The Clymer manuals directions on checking gear oil levels. Got that done and have started cleaning up the light sockets, turn signals brake lights and parking light sockets. I have ordered some duckbill pliers and hopefully they'll arrive tomorrow so I can go forward with the rest of the electrical connections. I haven't opened the headlight bucket yet, but when I do I'll let you know what I find. I am going to replace the oem fuses with the newer mini fuses. I am ordering a new voltage regulator? from euroelectric. Once I figure out how many fuse holders I'll need I'll get them ordered as well. My brake master cylinder is under the gas tank so I am curious to see what I'll see under there. Really am enjoying working on the bike. Haven't broke anything yet so I hope my luck continues. I disconnected the negative terminal from the tranny case to avoid any electrical mishaps. I will update the progress I make. Thanks again for all your help. 

ReplyQuote
Topic starter Posted : 07/12/2021 19:52
Richard Whatley
(@wobbly)
Member Moderator

@john-young Please read the latest Welcome letter in the Discussions area placed there today. The third part of my response deals with brake m/c under the fuel tank. This is a "must read" that I don't have time to repeat.

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

ReplyQuote
Posted : 07/13/2021 07:22
John Young
(@john-young)
Eminent Member

 I have completed the turn signal connections, parking light and brake light connection cleanup. The next stage will be to get the connections to the battery and under the tank cleaned up and hopefully there isn't much if any brake fluid damage there. Moving forward I'm going to put an led headlight and led brake light to lessen the alternators work. I have a new v. regulator coming and eventually brighten the lighting to the instruments for better night time driving. 

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Topic starter Posted : 07/15/2021 12:30
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