Lads, Just returned from 1300Km ride. Noticed at cruising speed (100 - 130Km/h), after 15 -20 minutes, the warning light starts to flicker on and off, then goes on solid. Dabbing the front brake will clear the alarm for a few minutes and then it starts slowly to flicker on and off again. Riding with the lights on. Switching to high beam made no difference. Switching the lights off (thinking it might be a dodgy lamp) made no difference. Dabbing the front brake will always clear the alarm. Also, the engine seems to be mis-firing, but not radically, just noticeably every now and then, but still seems to be going OK. At lower speeds, (<80Km/h) the problem goes away. The bike has ABS. The weather was warm to hot and humid.

- does anybody have a list of all the things which cause the warning lamp to light up.
- any ideas as to what is causing this? Could it be something to do with the load shedding relay?

(BTW, haven't drained the gearbox oil yet to see the state of the drain plug, re: slivers stuck to it.)

Thanx, Rick G.

why don't you take high blood pressure pills? It could solve your problem.
I don't have any experience with ABS, but if touching the front break will clear the alarm, I suspect that the break switch is not properly adjusted or it is faulty.
The problem with this type of micro switch is that the plunger is made of.... plastic and with the road dirt it has the tendency to get scored and stick.
This switch is the same as the one on the clutch and on the rear break (1985).

Here is the ref number:

My warning light started to flicker on a ride recently. Dabbing the brakes did nothing. Next time I turned on the ignition, dabbing both brakes did not turn off the warning lamp. As I wasn't sure what the warning lamp was really for (PO just told me that dabbing both brakes made it go away...) I reviewed the wiring diagram in my Haynes manual to find it is a light monitor / blown bulb warning thingo. A quick check of all the things the wiring diagram indicates it monitors revealed my tail light filament had blown. I therefore suspect you have a filament that has broken, but still making contact most of the time, as mine presumably was before it blew completely. The little black box can't monitor something unless it is 'on', this is why the circuit logic forces you use both brakes at start up - so it can check both switches light the brake lamp. I suspect it is nothing to do with your brakes and is instead either your park, head or tail light filament. Given the physical nature & loading of the park (short / small filament) and head (lotsa current) light filaments, I suspect it will be your tail lamp filament, as mine was.

Stout, Just before my recent long ride I actually had a blown tail lamp. The warning light was on solid and when I switched the lights off, the warning light also went out, indicating that it was actually a blown lamp. Also, at start up and when you begin rolling, dabbing both brakes extinguishes the warning light, as it should. This indicates that the lamp monitoring doo-dad works. Perusing the Haynes manual, the warning lamp is ONLY associated with lighting circuits. I've just now removed the RHS switch assembly (as per Bert's suggestion) to check the microswitch associated with the front brake. Sadly I didn't check to see if dabbing the foot brake only cleared the alarm. Before I removed the switch assembly, I put my ear to the front brake lever and could hear the microswitch click with application of the front brake. Now, if the microswitch was dodgy, it would either be permanently closed, permanently open or intermittent, no different to applying the brake while riding. My son, riding behind, always saw the brake light come on every time I dabbed the brake. Will persevere with the microswitch as a start.

I would also think that if the stop light was blown, the warning light would come on every time you applied a brake.

Your problem could be due to vibration at certain speeds giving a poor connection on one of the bulbs. I suggest that you tke off the rear light assembly Mainly because it is buried at the end of the tail assembly and give all connections and the bulb holders a thorough clean including the connections to the plug and socket which connects the light to the cable loom.

Also clean up the body of both bulbs and ensure they are giving a solid connection to the socket both on the filament pole and the earth. I suspect that should clear your problem.

As always DeoxIT is your friend, it was the only thing that permanently fixed bulb monitoring alarms on our Volvo by cleaning and treating every bulb and socket with DeoxIT the false alarms on the monitor circuit went away.
Regards,
K-BIKE

Conclude you renewed the brake light with the correct bulb previously? IIRC the 5 Watt ones are in abundance, but the 10 Watt is needed. Using the 5 Watt one will give intermittent warning lights.

No, I only replaced the tail lamp and not the stop lamp. The tail lamp was 5W and I replaced it with a 10W. Will check the stop lamp asap, as well DeoxIT-ing. Thanx!

That's interesting Renez (and Rick).

Mine had a 5w in it as well but I only had 10w in my garage stash, so that's what I replaced it with. I noticed a few days later that both 5w and 10w were available at a local auto parts store here, but saw no harm in keeping a sightly brighter tail light.

Looked at mine...10W tail light (replaced recently) and 21W stop light. The Haynes manual indicates that these are the correct Wattages. Anyway, DeoxIT'd the lamp and holders. Further rummaging around the internet took me to an article that alludes to the thought that the lamp monitor electronics and the ABS control business are somewhat inter-related. Only scanned the article, (Looked a bit complicated!) but will try and digest it in some detail.

Haven't had a chance to go for a longish ride to see if there's any change.