One of the last jobs on the Atlas after fitting some indicators and a modern handlebar switch was to reconnect the rear light .The first connection an earth from the loom to the numberplate immediately caused the headlight and front pilot to go very dim. As none of the rear lights are connected this is a puzzle . I thought you guys might like a little brain exercise before I dive in.
Question is where you did a mistake. I presume that everything worked before you fitted indicators and new switch. So step back as many steps needed until everything connected works.
The new handlebar switch might be faulty. I fitted a cheap chinese keyswitch to a BSA. Tested it before fitting, But it turned out to malfunction under load. Tried another one. Same outcome. Fitted a high priced keyswitch intended for boat use. Problem solved.
Fit a bulb in place of the fuse and start throwing switches and removing bulbs etc. The bulb brightness will show the current draw.
My guess for an answer to this dimming issue would be a conflict of polarity. I purchased a modern switch for my Atlas and quickly found that the wiring colours were totally random and what I assumed were negative and positive wires did not conduct current in the direction required. Time for a meter man.
Thanks guys, We have messed with most of the electrics while the bike has been in bits, I was a bit stumped with the fact that I had metered the earth wire to check it is an earth before connecting it to the rear light body . I'm thinking one of the flasher wires must have earthed on the rear light and is somehow carrying the live ,even though it has not been switched on at the bar switch. All very strange as I had the indicators working the day before . My head hurts!!.
If you remove the last fitted earth earth wire, does it still dim the headlight? If so, something else is obviously wrong. If not, connect another ground wire from the tail lamp to the earth side of the battery. Depending on if you have positive or negative earth. If not dimming headlight now, you'll know what to do. If still dimming, something earlier fitted is wrong. Please tell what happens.
I will be glad to get this done, No 1 son is getting very ratty ,not been able to ride since last year.My normal magic mechanic status has long evaporated and I have become an object of derision .Covid 19 took me to a dark place I have never been ,total apathy,no drive to complete anything. No IOM holliday ,workshop in total chaos, stalled DIY projects everywhere. Its now over 6 months since we had it . If it were winter and the usual dearth of bike possibilities I think life would seem pointless. Thank god for an involving hobby ,we are blessed.
The Atlas is a rough old dog, but always willing and has kept going with minimal input for many years,whatever we do to it has opened a can of worms . We more or less anticipated the same with the electrics. I connected up the indicators and lighting to the rear,leaving the troublesome earth wire unconnected. The mudguard seems to be an adequate earth and all is working.I can only think the light feed (pilot ) must have a short to the earth lead somewhere ,but why it only shorts in one direction is a nonsense!!. Moving on to installing the new saddle fixing and the kit supplied by Andover could never work. Just as I said,a can of worms!.
My last baffling electrical problem was self made...trapped a wire under a mudguard stay bolt. Have you made some change other than electrical?
Head blasted, new guides,valves,seats multi angled,pistons re-ringed lightened,balanced.
Robert; I’m an electrician by trade, tinkered with bikes a long while (though little to do with fancy things like indicators) but happy to visit and help out, fend off the whipper snappers and get to basics with this issue. Where are you located? I’m M1 J25 UK. I travel to Belgium/ Holland frequently in normal times. If it’s not possible to meet up we should exchange some diagrams and tips on keeping the youngsters amused.
You didn't happen to fit a LED pilot bulb?
Hi Jonathan, I'm always happy to meet up with another Norton sufferer!. And if your passing on your way you will be welcome to a cuppa /beer or workshop assistance. We seem to have resolved that issue by the well established method of ignoring it !.The bike is happy to provide its own earth thro the mudguard so we have left the annoying wire to its own devices. We have fitted LED indicators (pos earth) with a repeater bulb and tweaker. Most things now controlled by a modern multifunction bar switch (so cheap I bought two!) . The switch came with no wiring diagram (of course!) and the LED set with several bits of information that did not really gel. Pos earth just adds to the confusion. Determination is the main requirement . Startup should be soon and I am fretting that the weird multi piece (similar to Cords but with even more parts) rings will be ok . In the meantime my 50 year old Dutch niece is visiting and has decided she wants the leather biker chick lifestyle and is looking for a "proper" motorbike . I think SV650----she thinks MT07. after passing her test. A bit too much I say.
OK at least its working. If the two headlamp bulbs were glowing there must be a Potential Difference across the filament. Either side was connected to a reduced supply level. As they say, all resolved and no smoke blowing.
The SV650 is a perfect starter bike, all will be measured from that in her future...
I ride with a cousin on an early Deauville who likes old bikes and collects most of the bits as they fall off in front of him. It was such a good bike he could never get rid of it.
Will be in touch before my next passing .
Very best regards