Lightweight Wiring Diagram

patchy-man · Post by **patchy-man** » Thu Nov 22, 2007 1:04 pm

With reference to my 1960 AJS 350 Lightweight Model 8 restoration project, I would appreciate any help regarding the correct wiring diagram and colour coding for this model. The bike does have the original wiring harness fitted, but the wiring colours differ from any wiring diagrams that I have looked at for Lightweight models ?

I have also purchased a new small solid state rectifier, as the original seems to be kaput, and need help as to, how to correctly connect and wire the new rectifier ?

Many thanks in advance.

patchy-man · Post by **patchy-man** » Fri Nov 23, 2007 1:30 pm

With reference to my earlier post regarding the correct wiring diagram colour coding, unfotunatley I`m an absolute novice, when it comes to electrical wiring, and have confused myself by trying to follow a wiring diagram with different colour codes, resulting in various bulbs lighting from both headlamp switches!!!

The rectifier I have also purchased is a "encapsulated silicon rectifier" What is the correct way to wire this?, as it has four terminals, and the old original coming off only has three terminals.

Many thanks.

itma · Post by **itma** » Fri Nov 23, 2007 2:10 pm

one of them is probably an earth wire, did you not get a diagram with it?
Likely enough your harness is not an original one, anyway, just an old replacement one.
Chose one diagram and stick to that, if you have trouble stick a bit of masking tape on each cable end and write its home tag on it.
Electricals are not such a big deal, just relentlessly logical.
It helps to think of each wire as a water pipe, ie if its getting in at one end,and not coming out the other its a leak or a blockage.

Don Madden · Post by **Don Madden** » Fri Nov 23, 2007 4:35 pm

Since your new rectifier is not original & there are many types & shapes of replacements, a description of what your new one, with any markings at the terminals, (+, -, ~) is needed.

I will make some assumptions based on common bridge rectifiers: The (~) terminals connect to the alternator, & don't care which way.

The (+) is the positive output, connected to earth originally, but if you have any modern solid-state electronic devices, you must connect according to them, as modern vehicles use (-) earth.

The (-) was the original live output, with the (+) to earth but, as stated above, connect according to an modern devices, if any are fitted.

Cheers, Don.

bag-o-nails · Post by **bag-o-nails** » Sat Nov 24, 2007 8:46 am

there are four terminals on the solid state
two are for the alternator (green/white)

the alternator posts are the larger ones that face the same direction it does not matter which way round they fit

the terminal with the + connect to the earth post from the battery

connect the brown from the ign s/w to the only
remaining terminal

cheers b-o-n

paul knapp · Post by **paul knapp** » Sat Nov 24, 2007 12:24 pm

Just curious here, but wouldn't the positive terminal from the rectifier go to the positive battery terminal, either directly or via the frame if its a positive earth machine?

or is that what is stated in the 5th. line above?

Just wondering

Cheers, Paul.

bag-o-nails · Post by **bag-o-nails** » Sun Nov 25, 2007 10:01 am

G'DAY Paul

yes sorry if my discription sounded a bit confussing i did my best to kiss

thought it best to say how rather than why
confusing my self now!!!

cheers b-o-n

patchy-man · Post by **patchy-man** » Mon Nov 26, 2007 3:50 pm

Thanks guys for the assistance and instructions. I will have a go and let you know how I get on.

patchy-man · Post by **patchy-man** » Sat Dec 22, 2007 12:02 pm

I`m still struggling with the wiring on my 350 Lightweight. The ultimate aim is to obtain a spark at the plug ?
As mentioned before I have purchased a "new" solid state type rectifier to replace the old original one, and after stripping back some of the original harness covering to check and trace colour coding and connections, I still seem to be confused
I have three wires coming from the alternator, yellow, orange, green.
I would like to know where the go to in relation to the new rectifier? The old rectifier had, from left to right - green, brown, yellow wires connected to seperate terminals.
I also have a red wire coming from the points which I assume goes to the "new" coil?
I have also purchased a new 6v battery, and have no idea which wires go to that either.
I`m a total electrical novice when it comes to bike electrics, so any step by step instructions, would be appreciated.

paul knapp · Post by **paul knapp** » Sat Dec 22, 2007 1:53 pm

The bridge rectifier you apparently have should have one positive terminal which is to be connected to the positive pole of your battery, either direct with cable or through the frame.
There should also be a negative terminal which must end up connected to the negative pole of the battery, once again, either by direct cable or through the frame (depending whether the machine is wired negative earth or positive earth)
The other two terminals are for the AC current coming from the alternator. Since you have a three phase alternator, any two of the three alternator wires can be connected to one of the rectifier terminals marked ~ ,with the third alternator wire connected to the other ~ terminal on the rectifier.
At this stage, you are only converting your AC current to DC, so you must also have a regulator fitted in the circuit so as to regulate these DC volts to suit the charge rate of the battery.

Have a look here. http://www.sparxelectrical.com/acatalog ... htmlEdited by - paul knapp on 22 Dec 2007 2:05:31 PM