Turn Signal Flashers

[pmdave]

My R100t (with sidecar attached) still has the stock turn signal flasher, that huge box with multiple contacts and double relays. Well, it flashes the indicator light for left turn, but only flashes once for right turn, and then does not continue to flash.

The right side turn signals are switched to the sidecar light, but there are still two lights out there on the fender, so the current draw should be the same as with the bike RH turn signals.

I'm thinking of replacing the big BMW flasher unit with something smaller and simpler. Anyone have experience with auto flashers? Preferred type? How do you wire them up?

pmdave

[ThommyT]

I excerpted from an earlier post of mine "4 Way Flashers work but Turn signals don't":
>>I finally spent a little time with my twin ('84 R80RT) and discovered that if I listened closely when first turning the key on, if I heard a click from under the tank, the signals and flashers would both work- if I didn't hear that click, they would not work. I assumed that was a relay unit under the tank and for one of the very rare times in my life, assumption was correct and replacing that unit fixed the problem, until one of the rear signals stopped responding - that one was easy - a loose wire in the connector under the seat that connects the front harness wires to the rear one, leading to all the rear lights. easy diagnosis and fix on both cases - just needed a little time devoted to the careful ruling out and in of theories - or in reality, being lazy and trying the easiest things first, and lucking into a diagnosis and repair. Either way it was satisfying...>>

I'm not a mechanic or an electrical engineer by far, but it sounds to me like your issue is either wiring, or connection at flasher, unless the flasher box has separate flashers for each side. You didn't state the year and I don't know how different the 800 and the 1000 are in this area, but I also have one more thought:

Please forgive me for stating the obvious, but I know sometimes I skip right over the simple and over complicate...not to put you in the same category as me, but... You did check bulbs and test sockets, right? Try working your way back from the offending lamps.

Recap: unless there is a separate flasher or relay for each side (which I have not seen in my minimal experience) it seems more likely to be wiring connection somewhere shorting out or bulb/socket issue. Usually, in my limited experience, the wires split to go to separate sides after the flasher and relays...

Typically if you use a generic flasher (TRITON makes one-AutoZone) you lose the circuitry (in the flasher)that gives you bulb failure feedback from what I have read. I can get you number of the TRITON flasher unit that works with my bike when I'm in my shop if you want.

There are also some good articles from the BMWMOA ON that discuss relays and flashers and airhead circuitry. I have, over time, copied some pertinent info into Word so I can reference them at anytime. If you'll send me an email at ttolson1@earthlink.net, I'll send them to you. This is just a friendly exchange of info, no copyright infringement intended.

Look at your manual(s) also, there is good info to help you investigate along with schematics. Electrics can be a bear sometimes, but it's not magic. If you have Haynes get a Clymer's too or vice versa. Each have somewhat different approaches and info.

Sorry about the vowel movement. Hope I haven't offended or stepped on toes. I don't claim to know much of anything, just what I've stumbled onto along this journey... Best wishes. Let me know what you learn.

ThommyT (R80RTRIDER)
Just a few thoughts. Hope it helps. :dunno

[James.A]

Dave, I use the cheap little automotive flashers in my /5's and they work fine. I do have a later headlight shell with a flasher in my parts boxes. I will check out the connections relative to a wiring diagram and get back with you. I'd be pleased to send you this spare flasher for the purpose of a swap-out trial.

[James.A]

O.K., I did some reading and head scratching, and here is what I have come up with. I have this spare flasher, part # 1 244 377.2, Dated 2/83. It has 3 lugs, or spades, numbered 49, 49a and 31. 31 and 49a are the turn signal circuit, 39 being the ground wire, with the thumb switch assigning the flashing effect to R or L. Spade/lug 49 is involved with the front and rear brake light switches in parallel. Based on what I found, I would suggest that the problem is in a ground on the non-flashing side. The wire colors on this scheme(late 70's to '84 R80 ands R100) are brown(39)green/yellow(49a) and green/black(49) The 31 and 49a turn signal circuit is consistent with later, more elaborate flasher relays as well.

[pmdave]

Thanks for the ideas, guys.

I haven't yet taken the time to scrutinize the schematic. Somewhere in the back of my mind I recall the left signals using the right side as a ground path an vice versa.

I did find an auto parts store clerk who reluctantly dug out an old parts book with schematics for turn signal relays. (at first he said they didn't have that information) So, I have a three-terminal relay now, good for experimenting.

It could well be that the ground path back to the motorcycle frame has a resistance (corrosion, etc.) There is a separate ground wire from the sidecar, but none of those connections have been cleaned for many years.

I'm assuming that if the indicator (in the instrument cluster) works correctly when the left signals are selected, that the connector pins, circuit board, etc. are good.

Anyhow, thanks for the brainstorming. I'll report back after I solve the problem.

pmdave :thumb

[rocketman]

My R100t (with sidecar attached) still has the stock turn signal flasher, that huge box with multiple contacts and double relays. Well, it flashes the indicator light for left turn, but only flashes once for right turn, and then does not continue to flash.

The right side turn signals are switched to the sidecar light, but there are still two lights out there on the fender, so the current draw should be the same as with the bike RH turn signals.

I'm thinking of replacing the big BMW flasher unit with something smaller and simpler. Anyone have experience with auto flashers? Preferred type? How do you wire them up?

pmdave
I had a similar problem a few years ago, one side worked fine, the other side would work but the indicator would stop flashing after the second flash. After going round and round on this checking everything I could think of I looked at the blubs. thats when i found that one of blubs on the side that caused the indicator to stop after 2 flashes had a higher resistance than the other blubs. After I changed it the indicator worked fine for both sides. Somehow the higher resistance caused the indicator to stop flashing while the main blub continued to flash. bizzare, eh? So try changing the blubs around and see if the problem follows the blub switch.

RM

[pmdave]

Hey, that's good input! And the bulbs are easy enough to check. It could also be that a corroded bulb socket is making itself a resistor.

Thanks for the idea.

pmdave :clap

[pmdave]

It turns out that Rocketman was spot on. One of the bulbs in the sidecar fender was a 10W instead of a 21W. Changing to a 21W immediately solved the problem.

There was nothing wrong with wiring, grounds, switch, connections or turn signal relay. The Ural fender has two separate light units, each with two bulbs. So, with two 21W bulbs the draw is the same as the R side lights on the bike. (which are switched off when sidecar is attached)

Could it be that the German engineers planned it this way--so the turn signal indicator light wouldn't flash if one of the lights burns out? In any case, with the stock flasher relay, if it flashes on one side but not the other, it indicates a bulb burned out (or just too low wattage)

Thanks, Rocketman.

pmdave :thumb

[James.A]

I learned something today.

[ThommyT]

Ahem...ahem:

excerpeted from above - I know I'm verbose, but there can be pearls in there:

Please forgive me for stating the obvious, but I know sometimes I skip right over the simple and over complicate...not to put you in the same category as me, but... You did check bulbs and test sockets, right? Try working your way back from the offending lamps.
:D

hehe

oops, seem to have pulled some muscles patting myself on the back... :brow

glad ya got it and it was something that easy to fix. :thumb

[jcofwmburg]

My '74 R90/6 turn signals worked intermittently. So I put in a $4.00 auto type unit following Matt P. instructions from July BMWON. Now the turn signals work but the instrument cluster turn signal light is on all the time. It does flash along with the turn signals but otherwise is always on. I have emailed Matt but no reply as yet. Anyone know of this fix and how I may have mucked it up?
JC

[ThommyT]

John,

I wonder if your symptoms are result of some conflict with the BMW circuitry... or a bad bulb/socket? See reference(s) in the article regarding difference between generic flashers and BMW's (BMW's has circuitry that indicates bad bulb) and earlier post in this thread regarding bulbs/sockets. Just a thought...

It seems like for my '84 R80RT I bought a Triton "triple pin?" generic flasher unit at AutoZone. It did work on my bike and the indicator did not stay on as you described, that just wasn't my problem.

I bought a BMW flasher unit (both worked on my bike) when trying to diagnose my intermittent signal issue (turned out to be a bad relay under the fuel tank - see earlier post in this thread). I have no use for the flashers now, and I'd probably just lose track of them if I kept 'em anyway. I'd rather see you use 'em, if one of them will work for you. If you can find out from a dealer or parts supplier if the same flasher for the '84 R80RT would work in your '74 R90/6, I'd be happy to UPS them to you. We're both in VA, so it should get to you next day.

That about covers the extent of my knowledge (minimal) on this (or any issue, for that matter). Hope this helps and/or Matt gets back to you, for he REALLY DOES know what he is talking about as opposed to me...No real answers, but at least I made a few suggestions and offered the flashers...

Hope this post makes sense, just got home from a 630 mile, 9 hour drive (on 4 wheels) from GA to Northern VA... :snore

My email is ttolson1@earthlink.net if you want to contact me directly. Let me know if you want to try them...

Say goodnight Dick... Goodnight Dick :snore
(Anybody recognize that^? What's it from?)

Best of luck, ThommyT (R80RTRider) (and... GASP... '93 K75Rider)

[rocketman]

It turns out that Rocketman was spot on. One of the bulbs in the sidecar fender was a 10W instead of a 21W. Changing to a 21W immediately solved the problem.

There was nothing wrong with wiring, grounds, switch, connections or turn signal relay. The Ural fender has two separate light units, each with two bulbs. So, with two 21W bulbs the draw is the same as the R side lights on the bike. (which are switched off when sidecar is attached)

Could it be that the German engineers planned it this way--so the turn signal indicator light wouldn't flash if one of the lights burns out? In any case, with the stock flasher relay, if it flashes on one side but not the other, it indicates a bulb burned out (or just too low wattage)

Thanks, Rocketman.
pmdave :thumb

Glad it worked out to be something simple, It drove me totally nuts, for I forget how long when mine started acting up! Way back in the dark ages when I had a Kaw Z1A I had some similar happen, when I hit the brakes the headlight would flash! Turned out there was a short in the taillight blub, when the brake light came on it shorted to the tail-headlight circuit so the headlight would flash. took a few days till I realized the last thing I had done before the problem was replace the tail blub! It's things like that that can drive you nuts. Ha Ha.

RM

[Bob_M]

The composite knowledge on this forum combine into pure genius. It is a wonderful thing. :thumb