Late Navigator wiring loom

Have a word with Al Osborne, heâll sell you a kit, heâs the clubâs electrical expert, his website is AO services I think.

Dan

Hello Nick,

Someone was advertising new wiring looms for the Jubilee/Navigator fairly recently on Ebay. They seemed to do two versions -one had the proper Wipac switch connectors and another without - at different prices. It was an English address. I think it said they were made to order and not a stock item. There was some comment about the resistor wire not being available and to use something else to compensate. I know nothing more about them so can't say if they are correct or not. I am fairly certain that they were cloth covered.

You do surprise me with your comments on the loom from Norvil as it would seem strange to have new looms made which are not correct. The wiring loom was Wipac - not Lucas. They may be for a Bantam with some modifications. I do remember Bantam John telling me (ages ago) that he had the correct loom for the Jubilee and was very sarcastic that some people thought it was the same as the Bantam but with some extra connectors for the ammeter -it isn't if you want to be correct.

Patrick

Search Ebay under Norton Navigator wiring harness. Seller is 5* Flea Market at Burnley. His ad gives the impression that he knows what he is talkng about.

I see ads as well for "new genuine Lucas" wiring looms for Jubilee etc from other sources. A bit like saying a new genuine diesel engine for a Jubilee.

I need a new wiring loom for my 1964 Jubilee; it does not have a loom at the moment. I am thinking about buying one on EBay but all you have is a picture to go on. I will be doing the 12V conversion and I know some say it is not worth buying a loom if you do the conversion but I would rather start with a loom and adapt it.

If anyone has bought a light twin loom with Wipac sockets from EBay I should welcome their comments on its suitability and quality.

Bear in mind, that the original looms had a resistance wire built in - in its own asbestos? sheath. The resistance wire was important if you are sticking with 6volts, as it controlled the charging. Modern looms assume 12v - and that you will be using a regulator of some sort - Zenor Diode, PowerBox, etc.

With regard the 'standard' loom, NOS is always suspect as after some 50 years or so even if the loom has never been used there is still some tarnishing of the wires and connectors so be aware. New looms might be ok but as you seem to be aware the 6V needs the charge reduction resistor (used when the lights are all off) a new style ceramic one of 10 Watts or so should be ok but I have seen several dreadful attempts at this resistor. Again before keeping it original 6V please check out the words re 12V and electronic ignition on my web site. 6V (if you must) then an original loom might be ok but 12V and electronic ignition and a fresh loom/start is needed.

I have 6v navigator wiring loom with resistance wire and points on my bike, but it constantly needs watching. Everything works as it should but the output from the alternater has to match the load taken off. Bulb wattage needs to be tailored so that the ammeter hovers between slight charge and discharge.

6 volts is the problem that most affects reliability because current consumption is twice that of 12volt,. any intermttant fault in the switches or bulb holders or bullet connectors messes up the system ( usually on the move) , which can be hard to trace back in the workshop. 12volt and electronic ignition wil happen when I get fed up with my 6volt system.

Ithought the resistance wire was only used on side lights ? ?

Hi Nick,

I totally agree with your philosophy about keeping things original as far as is reasonably possible Both my De Luxe Jubilee and De Luxe Navigator run very satisfactorily with points ignition and 6V systems. They are a bit fiddly at times but you can do roadside repairs (if needed) quite easily. If the electronic system packs in that means a trailer home. Anyway why should someone buy an old machine in the first place if they immediately update all the systems by changing the old drum and cable brakes to hydraulic triple discs, fitting modern electronic ignition and charging, etc etc. Surely the intention is to remember the 'joys' of yesterday riding/driving.

I think that the resistance wire only comes into play when the ignition is On normal and all lights are off. My ammeter stays on the plus side again without any signs of overcharging.

We have just returned home in the 1958 Morris Isis after a 20 odd mile run to a local show; points ignition, drum brakes, standard Lucas dynamo, - no power steering, no servo brakes,no electric windows, no sat nav, no heated seats but it drove there and back absolutely faultlessly; just like it would have done when I was a learner driving a Morris Isis on L plates.

Patrick

Nick,

I could not wait as my Jubilee is nearing completion so I ordered a loom off EBay from Bill. It arrived today and looks pretty good with soldered bullet connectors and Wipac sockets.

I too have now decided to get the engine running on a 6v system and then think about converting to 12v and electronic ignition. It is more expensive to go down that route but I need to see the engine running before I invest yet more money on a bike that I bought in bits.

Just to get this right. The Lucas alternators RM15 -RM19 all have three wires out. This gives 1/3 output BLK/GRN and 2/3 output GRN/YLW. But the WIPAc as fitted to the Lightweights although having three wires have 50/50 between the two out put wires (YLW and ORN I think) this means that on ignition only the Wipac tends to want to over charge the battery so it incorporates this resistor in the loom. On side lights we need a little more output so this resistor is removed (By lights switch.) So the result of having no resistor is slight over charging of the battery when on ignition only. You can offset this by riding with the side lights on.

Previously Alan Osborn wrote:

Just to get this right. The Lucas alternators RM15 -RM19 all have three wires out. This gives 1/3 output BLK/GRN and 2/3 output GRN/YLW. But the WIPAc as fitted to the Lightweights although having three wires have 50/50 between the two out put wires (YLW and ORN I think) this means that on ignition only the Wipac tends to want to over charge the battery so it incorporates this resistor in the loom. On side lights we need a little more output so this resistor is removed (By lights switch.) So the result of having no resistor is slight over charging of the battery when on ignition only. You can offset this by riding with the side lights on.

How would the lightweight wiring loom or switch connections need to be refigured if going from wipac to lucas alternator ?? One small change like this messes the balance.GRAHAM

That is looking good. That late blue colour certainly looks good.

Do we call 'her' Bluebelle?

Nicholas,

Would you please let me know which 'finned resistor' you bought on EBay. I can't seem to identify the right one.

Many thanks,

Dennis

Nick,

Yes it does help.

Many thanks,

Dennis

Nick, I bought two new a Wipac-pattern switches to go with the new wiring loom but I took them both out of the boxes before noting which one is the ignition and which is the light switch! Schoolboy error. They have no markings on them so I can't tell which is which. Do you know if they are connected differently internally or is the only difference the letters on each knob?

The switches are Wipac numbers SO 781 and 781.

I have a multi-meter so it might be a case of wiring up the bike and checking each switch position if they do switch differently.

Dennis

Hi Dennis,

The switches are interchangeable - the difference is only the knob.

Beat me to it!

dan

Al Oz recommends soldering short wires with a bullet connector at the end, to the switch connectors, it gives a more reliable connection, the connectors that came with my loom from the club certainly donât fit the switch well but are working for now.

dan

Phew! That's a relief.

Just got to work out how to fit the combined rectifier/regulator now.

Previously Nick Clarke wrote:

Dennis,

I searched on 'aluminium clad power resistors' and came up with thousands of variations! I struggled to find a 10W 3.9 Ohm resistor from the UK although found some from China / Hong Kong. I am no electronics expert but assumed that my ancient alternator is probably not producing quite as much power as it should so I chose a 10W 3.3 Ohm resistor from Phi Sigma Electronics (photo attached) - at a cost of £2.39! This is working although it gets very hot with just IGN selected so I have used a Jubilee clip to hold it to the frame as a heat sink - I suggest you check very carefully that it isn't overheating and a fire hazard if you try one! Bill from 5*Fleabay recommends strapping his ceramic resistor to the frame with a metal tie-wrap which got just as hot! I have found a 50w 3.9 Ohm resistor from China and ordered one as a second option but not due till 23 May so don't know if it will be up to the job till then. Hope this helps! Nick

Hi,

Another option is:-

https://uk.rs-online.com/web/p/panel-mount-fixed-resistors/1074125/

regards

Tony

Tony,

Thanks. The one I bought looks very like the one you suggest. I am loath to scrape powder coat off the frame but I assume the resistor needs a heat sink so good contact with bare metal may be required and perhaps some heat sink compound. Would copper grease be a viable alternative to heat sink compound which is very expensive; I have copper grease

Previously Nick Clarke wrote:

Dennis,

I searched on 'aluminium clad power resistors' and came up with thousands of variations! I struggled to find a 10W 3.9 Ohm resistor from the UK although found some from China / Hong Kong. I am no electronics expert but assumed that my ancient alternator is probably not producing quite as much power as it should so I chose a 10W 3.3 Ohm resistor from Phi Sigma Electronics (photo attached) - at a cost of £2.39! This is working although it gets very hot with just IGN selected so I have used a Jubilee clip to hold it to the frame as a heat sink - I suggest you check very carefully that it isn't overheating and a fire hazard if you try one! Bill from 5*Fleabay recommends strapping his ceramic resistor to the frame with a metal tie-wrap which got just as hot! I have found a 50w 3.9 Ohm resistor from China and ordered one as a second option but not due till 23 May so don't know if it will be up to the job till then. Hope this helps! Nick

Your idea that the alternator is tired and giving lower output is reasonable but your guess to go for a lower resistor is the wrong way, if you want to 'waste' less electricity then you need a higher resistor BUT at these values and charge rates it will make insignificant difference.

I can supply a resistor of 3.9ohms but I charge £5 because I have to send it to you (and maybe make a profit)

It lives!

Having fixed the new wiring harness to my Jubilee I am at least getting a good spark at both cylinders. I almost got the plug leads right first time I was only 100% out