Resistors and relays...

[Spinal]

Well, today I popped by a bike MoT garage to get my new MoT. Lo and behold, after mentioning on another thread that its an Italian bike AND I've never had ANY electrical problems with it... well... MoT failed... grumble... Nothing too serious luckily...

Point 1: Dipped Beam lights does not work
fair enough, I didn't realise motobikes had 3 light levels. I thought they only had 2. Tomorrow I will open the headlamp and check the bulb. (The "parking" and "high" beams work though.

Point 2: Nut on the brake lever (the one that you use to adjust the "slack in the cable") is missing. Another fair enough. I didn't even realise there was a nut on that bolt; I got the bike that way, but I'll shove a nut on that tomorrow.

Point 3: Indicators flash at more than 120 times per minute.
Hmm, haven't bothered measuring this one. I didn't know this was an issue either. Now, short of changing the relay; I had a quick look through the manual, then I remembered that the rear indicators were replaced by the previous owner. my guess is that the 2 rear indicators are a different resistance from the original ones, and hence cause this issue.

So I was thinking a quick and easy fix would be to find a different wattage bulb... (1/2 watts more or less). Problem is, I don't remeber my physics that well Do I need a slightly higher or lower resistance bulb? Or should I skip that altogether and just hunt for a new relay that will cater for the new indicators?

Michele

p.s. What happened here about 15 minutes ago? The forum seemed unreachable... hmmm...

 

[Stratman]

You will be lucky to find bulbs that differ by just a half watt or so. My guess is that the previous owner used whatever bulbs he could find in his box of bits, probably sidelight bulbs. Look in the handbook for the correct rating and you should be OK.

 

[Sp!ke]

Wondering if your new indicators have LED bulbs, in which case you need an inline resistor.

Failing that, you may find the relay itself is to blame - usually on bikes the relay is generic, any old indicator relay will do the job so expect to pay only about £5 or so.

 

[Spinal]

Perfect, thanks! They definetly are NOT led bulbs (had to refit one of the stalks after my tragic parking accident)...

I didn't know the relays were generic, I'll have a look around then... Might try a bit of both

Michele

 

[Ted]

The flasher relay should have the correct wattage printed on it (e.g. 2x21w or 2x18w etc). Check this and then check the bulb wattage.
If the two match up, and the lights seem the correct brightness, (unlikely to be four bulbs with dodgy connections) the fault will probably lie with the flasher unit.
IIRC, and the law hasn't changed, the flash rate should be between 60 and 120 flashes per minute, with the bulbs coming on within one second of the switch being activated, or going off within one second of being activated (if the lights come on immediately) - hope that makes sense.

 

[Ted]

Should have added that whether the flashers run faster with incorrect load or slower is dependant on the design of the flasher unit, - the law requires a visual indication of bulb failure.