fuse blown

[spartan]

On rebuilding a 1977 140 i had to install a new loom. Ive had the bike running and after riding a short distance the fuse blew.
Everything before worked perfectly.
I have traced it to the zenor diode which is new, but  every time i connect it  blows the fuse.
I also fitted a solid state rectifier does anyone know why this is occurring .
Ive also fitted boyer ignition
The bike was stored since 1984

Pete

[dodger]

Is the zenor diode earthed ok ,perhaps you have a loose conection .
When I have had a zenor  diode fail it has usually blown fuses and light bulbs, you could try connecting a volt meter to the fuse holder and a good earth on the bike rev the engine to 2000 rpm and note the voltage any reading above 16 volts or below 13 volts mean the diode is faulty.
Important note do not run the engine with both the battery and diode disconnected as this will  f**k the ignition system.

[spartan]

Dodger
The earth wire is earthed to the front battery carrier lug or rubber mounting securing bolt . i was told this by someone a forum, where should it connect to i believe this might be wrong as it is the main frame earth.
The aluminium air boxes have been powder coated but i have taken them all back to the metal where the bolts secure them to the frame.
I suspect a bad earth somewhere.

I have replaced the zenor with the original one when i get it running ill check if its working with a meter.

Pete

[steviepope2000]

Pete
Just curious about the solid state rectifier only, as I've only seen combined solid state rectifier/regulator units units advertised, like the Podtronics I've just fitted. These do away with the rectifier and zener diode. Is it possible yours is a combo and that you should have disconnected and taped-up your zener wire?
Steve

[spartan]

The solid state rectifier ive bought is a straight replacement for the lucas original which looked fried in the loom burnout.

The engine is earthed via the steady bar on the rocker casings but i was unsure where the two into one ring eyelet fitted for the frame earth.

What i think could have happened is the Zenor had no way of dumping the excess voltage due to poor earths.

I really would like to know where triumph earthed the frame, i intend to double up on earths. the indicators now have there own earths and work without a problem initially they wouldnt work at all.

The bike has been stove enamelled and i have gone back to bare metal where cases meet to get clean contacts.

I know just want the charging and ignition circuits working properly, then i reconnect the rest.

Pete

[dodger]

Its a long time since I ran a standard loom on my bike but I think the main earth point was as you say to the battery carrier mounting point or the airbox mounting on the main tube of the frame. I always run my earths back to the engine either the crankcase bolt behind the engine breather or to the head steady bolt on top of the rocker box. You also mention that the alloy airbox's have been powdercoated ,the diode not only needs an earth but it also needs to dump excess voltage ie heat and although it may possibly be earthed it is possible that it cannot disipate the heat because of the powdercoat between the diode and the alloy ?(I believe the diode needs an area of aprox 16 sq inches to disipate the excess heat)
One other thought is your bike + or - earth ?

[spartan]

The bike is a positive earth the diode is mounted onto clean base metal in the airbox.
I just want to make sure that i get it right first time, I cannot presume anything as the last loom burnt out maybe that was the reason the bike being off the road so long ie poor electric`s.
I take your point about the extra earth on the engine thats going to be done.
I could make an aluminium plate to mount the diode in the airbox, Ive done this with the rectifier it sites on a plate to disipate heat.

Pete

[dodger]

Triumph use to put an alloy heatsink (finned ) for the diode under the bottom yolk of the front forks on all the preoil in frame bikes. I once fitted one of these heatsinks just under the right air box side panel were it was in the airflow.
The reason I asked + or - was that it has been known to be supplied the wrong one by mistake.

[spartan]

Ive seen the front mounted diodes but i did want to keep it more or less visually original all the new electronic`s are hidden.
It came with the original points but ran very lumpy at tick over it is now sweet.
Well was befor this happened.
The Diode in the air box should get enough air movement from the air cleaners really but if it doesnt work i will rewire to the front heatsink type.


Pete

[spartan]

The problem with the fuse blowing was the Zenor Diode the readings i took with a digital meter on diode check told me the new one was shorting out the old one is fine and everything is working as it should be for the moment.
I dont like zenor`s so i am definitely fitting a rectifier regulator under the battery tray.
Increasing earths as suggested
Thanks for the input got there in the end hope i dont get as much troublke with the norton Commando ive just bought.

Pete

[spartan]

Ive just purchased a solid state Rectifier regulator it has two yellow wires which connect to the 2 ac generator single phase wires.
The other two wires are red ground and black supply do i just connect these to the battery.
Do i connect the black lead hot wire dirctly to the battery or before/ after  the fuse or does it have one of its own.

Pete

[dodger]

On my bike I dont use a battery just a capacitor so I connect straight to the capacitor but if you are using a battery I would advise using an inline fuse  before connection to the battery.

[spartan]

All sorted the introduction of a rectifier/regulator fitted under the battery box in air flow sorted out the problems NO Rectifier or Zenor Diode to worry about.
Voltage from the unit was a healthy 14.6 at any revs.
With the increased voltage i noticed the bike started easier with good voltage to the coils.
I have a Boyer system fitted but they prefer 6 v coils i have the original 12v one`s.

Pete

[Jubilee Ken]

Hi Pete, yeah get those six volt coils fitted quick-sharp, it will transform the bike