On my 78 R100RS we are having a problem with the indicator light for the turn signals not lighting. The turn signals and the four way flashers work fine, just the indicator light does not work. Swaping the console with another unit and swaping the flasher relay did not change anything. Checking the voltage to the bulb socket, there is very low voltage present, 1.2 volts. All connections appear to be clean and good, as far as we can tell, the system is wired properly.
Any thoughts as to what could be going on? St.
Beware! I do not suffer fools gladly! St.
I shall watch this with interest. My R90/6 has the same issue.
I'm no expert, but I'm willing to take a stab.... This could be several things, depending on the full description of the issue.
► If the Hi Beam indicator and instrument back lights also refuse to work (which may not be apparent if you no longer ride at night), then the entire instrument cluster may have lost it's "ground" connection. If you look at a schematic you'll see that most of the bulbs in the instrument cluster share a common return path.
That path could be upset by a poor connection at the large rubber connector on the rear of the instrument cluster. I had to smear No-Ox on my instrument cluster connector to get all my instrument lights working. The BRN wire that supports that "ground" function goes directly into the main harness with no other connectors, so if that's not it, then you may have a broken BRN wire inside the harness leading up to the cluster. This last is highly unlikely, but Occam's razor dictates it be included.
► If all other lights work OK, then it may be an issue with the bulb/ bulb holder. (You tried another instrument cluster, but that particular bulb is ON all the time and therefore short lived.)
[Here we have to issue a warning: To remove any of the bulb holders inside the instrument cluster you simply push LIGHTLY left, then push LIGHTLY right, and repeat until the holder pops out. DO NOT pull on the holder. DO NOT push up or down. If you do anything else you run the risk of breaking the fragile circuit board which is not available from BMW. If you simply cannot comprehend that working on the instrument cluster takes an extremely delicate touch, then stop and send it to someone who does.]
There are actually 3 common issues to the user serviceable instrument bulbs:
1) Blown bulb. Replace with a clear #194 bulb from your LAPS. (In fact, replace the bulb no matter what.)
2) Corrosion on the steel tangs of the bulb holder right where it makes contact to the copper of the circuit board. Scrape off any corrosion with an Xacto knife and apply No-Ox. (I had to do this on my 1988 just 2 days ago.) This will not only stop the corrosion, but make the holder go back into place much more smoothly.
3) When people get ham-fisted and stupid while removing the bulb holder, sometimes the extremely delicate circuit board folds up under itself, rather than have its tails protrude through the rectangular hole the bulb holder snaps into. When this happens you have to get out the dental tools and coax the tails back into position. There must be a copper leaf protruding through BOTH sides of each bulb holder hole or complete electrical contact cannot be made. It's these 2 tiny copper leaves (about 0.004" thick) that get damaged when repair personnel remove the bulb holders by pushing in the wrong direction, or by using too much force.
When replacing the rear instrument bulb cover, run the screws down until they touch and STOP.
Hope this helps.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
I am sorry, you did not read my question properly. St,
Beware! I do not suffer fools gladly! St.
Mine only happens when the key is turned to the headlight position. The indicator works in the running light position. I have chased any wires yet. ( Humidity and frustration are not a good mix for me.) I'd rather ride any way.
I am sorry, you did not read my question properly. St,
There is one more suspect place to check. Has the stock BMW 3-pole flasher unit ever been replaced with an American 2-pole flasher at any time in the past ? The flasher unit is typically located at 7 o'clock once you remove the headlamp reflector. The stock unit is cubical; US replacements are typically cylindrical.
If so, then I believe the 3rd pole feeds the indicator lamp. If you have a 2-pole flasher, then you probably also have a loose, un-connected wire with a female spade connector laying there beside it. If memory serves me correctly, you may need to double-up on one of those flasher terminals to power the indicator. Although you can buy a Y-adapter, the easiest thing to do is build your own with 3 appropriate gender crimp terminals and a very short length of wire.
Hope this helps.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Wire was in the wrong position. Problem solved. St.
Beware! I do not suffer fools gladly! St.
Wobbly, you did not read my question properly. See my other post for my comment. St.
Beware! I do not suffer fools gladly! St.
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