Headlight issue still won?t go away

TStanb

TStanb

Full member
1980 Series 1 Jota

As mentioned a few months ago, Hi-beam keeps fusing the 8A fuse in the fuse box BUT I have now narrowed the problem down a bit...
1. No problem when switching on lights with the dipper set on Hi beam from the start.
2. No problem using the PASS switch
3. It only appears to fuse when switching from Lo to Hi
4. The mysterious black/white wire from the new LH switchgear is now well earthed onto the main chassis, as recommended by a few members last time.

Relay problem??
 
Does it also blow the fuse going from high to low beam? Is there no problem with the lights switched on in Low beam? Only while switching either way?
As was mentioned iirc, switches often have an overlap between beams to prevent a dead point, with both beams activated together for a moment while switching. With a 55/60 globe this will pull 9.6 amps (4.6amps low beam/5amps high beam), with both beams on. You can check this with a test lamp (or two test lamps) or multimeter. Also check just how many amps are being pulled with an ammeter. Whether the current is taken to the globe through the switch or through relays won't make any difference.
 
Relay problem?
Click to expand...

Sounds like you have modified wiring, unless you're referring to the daytime riding relay?

Assuming standard, there's either a fault in your switch which is momentarily earthing the feed as you operate the switch, or you're firing the two filaments at the same time whilst switching. Although the latter will draw more current, an open fuse will usually hang on until at least twice its rated current flows, so I wouldn't expect it to blow in this situation unless you have massively uprated the headlight. So disconnect & check the switch with a meter to see what is happening.

Otherwise, would need to know wiring details
 
Thanks. I?ll look into these points tomorrow.
The problem has only been occurring since I sent my LH and RH switchgears away for re-furbing, so something must?ve changed. Problem is, I can no longer compare before and after as I never properly checked and mapped how it was before they went away :(
 
The switch mechanism is pretty basic inside.  If you take the unit off the handlebar you'll be able to see how it works. Not sure how extensive the refurb was, but I'd be looking at the soldering of the individual wires; clamping arrangement and also for loose / mislocated parts of the switch contacts
 
The wiring for the two rocker switches in the LH block is extremely tight, it's sort of alarming when you see it, hard to believe it works like that for so many years.  Highly likely something's been put together not quite correctly, an original wire has chafed through in the tight confines and shorted, or something along those lines.  If nouvo wire has been used inside for repairs etc and they've not used the correct size of thinwall automotive wire then you'd certainly have major packaging issues.
 
I?ve had a look inside the switch and, to be honest, it?s all witchcraft to me.
However, even I can spot that new wiring has been used in the refurb. I have opened up the HLP switch and it all looks in order and very neat and new. Can?t really see a problem
 
Then send it back to the person that restored it and explain the problem.
Surely they should be contacted as first option.
Possibly a wire has been wrongly attached.
 
Good news!
One of the little spring-loaded copper pads in the dipswitch was fitted upside-down.
All is good 👍
 
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