75 Mk III Electrical-Warning Light Control Unit

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Rondo

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Son and I have nearly completely wired the 69 commando with good results, it was almost understandable with my limited capacity for grasping electrical systems. We have now jumped over to the 75, different animal, we have electrical diagrams, loom diagrams, etc. and have decided to try and streamline some of the frills the 75 has. We are thinking about abandoning the instrument panel and possibly the warning light control unit but are not real sure of the purpose nor did we find these in our piles of parts.

Question is are we creating problems for ourselves by eliminating these? Maybe creating incomplete circuits that are required for the rest of the bike to function, etc. The control panel doesn't appear to have real valuable information on it but not understanding the value of the warning light control unit. Any comments would be greatly appreciated.
 
Rondo said:
Question is are we creating problems for ourselves by eliminating these? Maybe creating incomplete circuits that are required for the rest of the bike to function, etc. The control panel doesn't appear to have real valuable information on it but not understanding the value of the warning light control unit.
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Assuming it isn't a Canadian market model then all the warning light control (assimilator) does is switch the red charge warning lamp off when it senses alternator output has reached a certain level (and switch it on again when output drops) so the electrical system doesn't rely on the assimilator for anything other than that and disconnecting it won't disable any other circuits.
 
Rondo said:
snipped We are thinking about abandoning the instrument panel and possibly the warning light control unit but are not real sure of the purpose nor did we find these in our piles of parts.

Question is are we creating problems for ourselves by eliminating these? Maybe creating incomplete circuits that are required for the rest of the bike to function, etc. The control panel doesn't appear to have real valuable information on it but not understanding the value of the warning light control unit. Any comments would be greatly appreciated.
Click to expand...
Larry,
As Les mentioned above, no issues with eliminating the Assimilator. FYI, the assimilator is mounted on the top of the battery tray. You can't see it until you remove the stock air cleaner box.

75 Mk III Electrical-Warning Light Control Unit


Only issue regarding eliminating the console is you will need to find a new place or mounting plate for the ignition switch. Relocating the switch will entail modifying the wiring harness. Fabricating a new mount will entail more work and possibly expose the wires for the switch to the weather. Exposed ignition switch wiring makes theft easier.

Per Grant T., there are several aftermarket replacement units for the assimilator with improved/additional functions.

Gammatronix Voltage/Battery Monitors

Improving Classic Motorcycles

Improving Classic Motorcycles also offers a unit which allows the red charging light to also act as an oil pressure warning lamp. You would need to add a pressure sending unit to the engine for that additional feature. Several threads on how to accomplish that are here on the forum.

Charlie

PS Check your email
 
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chaztuna said:
FYI, the assimilator is mounted on the top of the battery tray.
Click to expand...

The first 2000-or-so Mk3s had the earlier 3AW silver can assimilator. If so, then the three terminals for the 3AW would be in the section of wiring harness close to the head steady.

Although the later assimilator (attached to the battery tray in chastuna's pic) has five connections there are seven wires in the harness at that point as two are alternative connections for the Canadian lighting control assimilator. All should be taped-up separately (or removed from the harness) none should be connected together.
 
L.A.B. said:
The first 2000-or-so Mk3s had the earlier 3AW silver can assimilator. If so, then the three terminals for the 3AW would be in the section of wiring harness close to the head steady.

Although the later assimilator (attached to the battery tray in chastuna's pic) has five connections there are seven wires in the harness at that point as two are alternative connections for the Canadian lighting control assimilator. All should be taped-up separately (or removed from the harness) none should be connected together.
Click to expand...
Les, I wondered how you could tell the early from the late assimilator. Thanks for clearing that up. The extra wires Les mentions above are the white and red wires shown in the photo below. The five wires used on USA models are to the left, the two wires used only on Canadian models are to the right.

75 Mk III Electrical-Warning Light Control Unit
 
Ahhh, we couldn't figure out the mismatched wire count coming out of the harness, we do have 7.
We intend to move the ignition switch below the seat on the left side where you see it on many other models. The 69 is in the side cover although I don't want to drill it in case someone wants to put this back into original condition some day, I'll make a bracket for it.
Thanks for the photo we do have some battery trays and I may have missed this part attached to it.
I also didn't know of these aftermarket suppliers and am anxious to see their products.

I have cleaned and reassembled the right hand handlebar switch controls and are a little wary of them (old and brittle, missing spring for BB) but seams like were stuck because I need it to hold on the master cylinder I just rebuilt? If it weren't for that we would consider buying new switches as they don't seem very expensive. Maybe there are other alternatives?
 
chaztuna said:
The extra wires Les mentions above are the white and red wires shown in the photo below. The five wires used on USA models are to the left, the two wires used only on Canadian models are to the right.
Click to expand...

The five standard (not necessarily USA) assimilator wires are white, red, green/yellow, white/green, white/brown.
The two Canadian wires are brown/green and blue.
 
L.A.B. said:
The five standard (not necessarily USA) assimilator wires are white, red, green/yellow, white/green, white/brown.
The two Canadian wires are brown/green and blue.
Click to expand...
I just referenced the wiring schematic in the factory workshop manual. There is a notation stating that the white and red wires are not used on Canadian models. It appears that my Mk III was configured as a Canadian model [last registered in the US State of Ohio 1982]. It will be interesting to see what I learn when I order the build info from Andover Norton for my Mk III.

Edit: Per the part number on my assimilator, it appears that my Mk III was originally sold or at least intended for the Canadian market.

75 Mk III Electrical-Warning Light Control Unit
 
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Rondo said:
Ahhh, we couldn't figure out the mismatched wire count coming out of the harness, we do have 7.
We intend to move the ignition switch below the seat on the left side where you see it on many other models. The 69 is in the side cover although I don't want to drill it in case someone wants to put this back into original condition some day, I'll make a bracket for it.
snipped
Click to expand...
Or just buy a used early model side cover with the ignition switch hole in it?? Not sure if there will be room behind the cover for the switch and wiring?? Replacing the stock battery with one of the newer, smaller & lighter LiFe [Lithium/Iron] batteries will increase the space available. It will also lighten the bike and your wallet.
 
Rondo said:
snipped We are thinking about abandoning the instrument panel snipped

Question is are we creating problems for ourselves by eliminating these? snipped
Click to expand...
You will be eliminating all the warning lights. Use of an earlier model headlamp shell would cure that and help hide those wires inside the headlamp. They are exposed on the Mk III.
 
I cant see how the assimilator is even used much due to its location? Maybe only as a servicing device?
 
chaztuna said:
Edit: Per the part number on my assimilator, it appears that my Mk III was originally sold or at least intended for the Canadian market.
Click to expand...

In that case, does it have the Canadian ignition switch?

chaztuna said:
You will be eliminating all the warning lights. Use of an earlier model headlamp shell would cure that and help hide those wires inside the headlamp. They are exposed on the Mk III.
Click to expand...

The console warning lights have their own sub-harness which can be unplugged (6-pin plug) and removed. The main harness plug section can then be hidden under the fuel tank.
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
 
Rondo said:
I cant see how the assimilator is even used much due to its location? Maybe only as a servicing device?
Click to expand...

I'm not sure what your thinking is or what the location has to do with use as it's electronic it doesn't matter where it is located as long as it's connected and works constantly when the engine is running to switch the charge warning light off when it senses a certain level of output from the alternator as I mentioned previously.
 
Rondo said:
My misunderstanding. Not having seen one, I thought the light was on the device.
Click to expand...

The warning light ("Ignition Red") would be on the console...that you are not intending to fit.
75 Mk III Electrical-Warning Light Control Unit
 
L.A.B. said:
In that case, does it have the Canadian ignition switch? snipped
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Ignition switch??? All that I found was the contact plate. I doubt this is enough to identify it. :rolleyes: Where's Waldo? Seriously, how does the Canadian ignition switch differ?

75 Mk III Electrical-Warning Light Control Unit
 
chaztuna said:
Seriously, how does the Canadian ignition switch differ?
Click to expand...

See Mk3 manual, Section J9, "CANADIAN MASTER SWITCH: Modes and Functions".

Also, the lower left-hand corner of the Mk3 wiring diagram.

75 Mk III Electrical-Warning Light Control Unit
 
Without the console you'd loose mountings for neutral safety and turn signals as well. Toss the assimilator as it only looks at AC voltage out of the alternator, not the actual DC voltage being delivered to the system so doesn't account for a bad diode or aftermarket regulator. Drop one of these in the red light hole and get some useful information. http://www.sparkbright.co.uk/sparkright-eclipse-battery-voltage-monitor.php

In my opinion if you want reliable charging and electric starting you should fit a 3 phase alternator which will keep good voltage even when stuck in traffic at night as the coming in speed is much lower. Some like a oil pressure warning light but my experience with a MKIII is that an oil pressure gauge is better as the conical seal can split and there can still be enough oil pressure to trip a warning light off well above idle but most oil will be spilling into the timing case.

AN has new face decals to spruce up the console face.
 
Jim, thanks for the heads up regarding the Spark Bright voltage monitor. I was unaware of that product. Here is a 4th voltage monitor offering. They also offer a version for Lithium [LiFe] batteries.

http://roadstercycle.com/
 
L.A.B. said:
See Mk3 manual, Section J9, "CANADIAN MASTER SWITCH: Modes and Functions".

Also, the lower left-hand corner of the Mk3 wiring diagram.

75 Mk III Electrical-Warning Light Control Unit
Click to expand...
After reviewing the differences in the Canadian model, they now all appear moot, unless you still have a functioning P/N 06-6625 ignition switch, or can find an NOS replacement. Andover Norton supersedes all other ignition switches to the more common P/N 06-6395 switch.

Andover Norton Mk III Ignition Switch

Does the Canadian assimilator [refer to photo in post #8] still function correctly with the 06-6395 ignition switch? Are Canadian model console decals still available? Did Norton [or local dealers] fit the Canadian assimilator for US States which had enacted "Head Light On" laws during that time frame? Current US motorcycle laws are linked below:

US State by State Motorcycle Laws
 
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