Warning light assimilator

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Supercat

Supercat

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Hey all,

Long time no post :)! I've been lurking here in the background reading threads and learning over the course of the winter, but the snow has only just melted enough to allow me to get out for a couple of rides over the past week. I've done a couple of little jobs on the bike over the last few months, but luckily I haven't run into any issues that required questions (knock on wood!!), until now.

I just fitted a new warning light assimilator can a few minutes ago and ran the bike briefly to see what would happen. The red light used to stay on all the time with the old can. The light comes on when I switch on the key with the new one, but it goes out immediately after the bike starts. I notice it even flickers out when I'm kicking it over. Is this correct behaviour?

BTW, the bike (72 Roadster) is running like a dream at the moment (knock on wood again), and I'm getting ready to install a Trispark ignition to replace a very aged MKIII Boyer that came with the bike. Hopefully things go smoothly with that job and she keeps on running beautifully. I'm planning to hold on to the Boyer as a backup just in case.

Thanks!!
 
Oh, a couple of other things I probably should have mentioned. Measuring voltage at the battery it's getting 13 volts at 2000 rpm, and a bit over 12 volts with the lights off at idle. With the lights on it drops to about 11.5 at idle but is up to close to 13 again at 2000 rpm.
 
The red light going out and your voltage tests show the alternator is working, battery needs testing by the looks of it.
 
Excellent, thanks Kommando! Sounds like my assimilator is functioning as it should, which is great news.

I've got an update now also: the Trispark has been installed and I started her up just for a minute to make sure all was good etc. Started in 1.5 kicks after putting the tank back on and immediately sounded significantly better than she ever has. Normally after I put the tank on I'm kicking at least 8-10 times to get the fuel flowing, so I was really impressed. Idled right away and voltage at the battery was 13+ volts at idle! More than 12 volts at idle with the lights on! Now to strobe her and go for a test ride :).

Thanks again!
 
Hi from New Zealand.
Are you aware there are 2 different types of warning light assimulator? I have a 1975 Canadian bike and have done some research on this.
I believe there was a law passed in Canada that stated the lights must be on when the engine starts, so the red light stays on to show the lights are on. The other type of assimulator used in the rest of the world is red when ignition is turned on and goes out after the alternator generates over a certain amount of power. There are 2 different part numbers for these. Not sure if this applies to earlier bikes
 
Hi Richard,

Thanks! I was aware that there was more than one type, but I was not familiar with the Canadian assimilator or the reasoning behind it. I knew that there was some kind of a boxy type one later on. Is the Canadian one that stays on to show the lights are on a square one or can shaped?
 
850commando said:
lights on became law in canada in 1974.
Click to expand...

"Machines manufactured after 1st January 1975" according to the Mk3 factory manual which ties in with the early Mk3 models having the 3AW siver can assimilator.
 
L.A.B. said:
"Machines manufactured after 1st January 1975" according to the Mk3 factory manual which ties in with the early Mk3 models having the 3AW siver can assimilator.
Click to expand...

Confirming research shows that the change over to solid state assimulator and therefore Canadian headlight module was very close to vin 327000. ;)
 
Super cool folks! Some interesting history there. Strobe timed it a little while ago and just came back from my first ride with the new ignition. Very impressed so far - seems like I can run lights all day long now with no worries about my battery going low and with no worries about low voltage kickback. She seems to be running better than ever, and kick-starting has become one of my favourite parts of the ride all of a sudden :).
 
Supercat said:
Hi Richard,

Thanks! I was aware that there was more than one type, but I was not familiar with the Canadian assimilator or the reasoning behind it. I knew that there was some kind of a boxy type one later on. Is the Canadian one that stays on to show the lights are on a square one or can shaped?
Click to expand...
The Canadian & rest of world assimulators are box shaped and fitted under the plastic air box, just in front of the battery tray on the Mk3. I have just removed mine, also the Zenner diodes, rectifier and the blue capacitor after doing a 3 phase conversion. Lots of redundant wires after this, which I have removed from a new main loom, before re wrapping
 
Supercat said:
Hi Richard,

Thanks! I was aware that there was more than one type, but I was not familiar with the Canadian assimilator or the reasoning behind it. I knew that there was some kind of a boxy type one later on. Is the Canadian one that stays on to show the lights are on a square one or can shaped?
Click to expand...
I also replaced the red light on my panel with one of these
www.sparkbright.co.uk.
I used their auto dimming eclipse version, one wire to earth, the other to the ignition on side of the switch. Seems to work very well.
 
Thanks Richard,

Those SparkBright devices do look intriguing. If anything goes wrong with my assimilator I'll probably go for the SparkBright next.
 
Is it possible to check the assimilator to confirm its bad before buying a new one?
 
Saber said:
Is it possible to check the assimilator to confirm its bad before buying a new one?
Click to expand...

Yes for the 3AW WLA unit
If you supply from a variable DC power supply slightly more than 6.5 volts DC, sometimes approaching 7 volt, the output terminal will open.
The reason for the low voltage is that the unit is run only off 1 leg of the alternator so 13 volts @ 50% duty cycle is 6.5 steady DC.

MKIII is different and the Canadian headlight control is NOT a warning light assimilator as such.
 
Thanks. The bike runs fine but the red indicator light quit working. If there is nothing connected to the assimilator and i get no continuity between WL and E - its bad right?
 
New assimilator from AN fixed the warning light issue. Fit perfectly in existing the existing spring like mount.
 
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